Cocoa Extract

Cocoa Extract is a bitter chocolate-tasting mixture that is comprised of xanthine molecules (theobromine and Caffeine) and an assortment of procyanidins. This extract appears to hold cardiovascular and cognitive benefit associated with improving blood flow.

This page features 189 unique references to scientific papers.

Confused about what actually Works?
MUST GET: Supplement Stack Guides - Saving You Money & Time


In Progress

This page on Cocoa Extract is currently marked as in-progress. We are still compiling research.

You can help contribute by:

Follow this Page for updates

Confused about Supplements?
Get the Stack Guides

Also Known As

Chocolate polyphenols, Cocoa polyphenols, Cacao polyphenols, Cacao extract, Chocamine

Do Not Confuse With

Chocolate (The extract paired with macronutrients)

Things to Note

  • There may be some stimulatory properties exclusively in those highly sensitive to the small Caffeine content of cocoa
  • While technically the bioavailability of cocoa can be influenced by diet, there tends to be no major differences in absorption between supplements and chocolate products
  • Dark chocolate tends to refer to 50% cocoa content or higher, and is seen as the best source of cocoa polyphenolics due to being both palatable and a dense source of polyphenolics. Unsweetened baking chocolate and unsweetened cocoa powder are better souces but less palatable
  • Milk chocolate is seen as a poor source of polyphenolics whereas white chocolate contains little enough to not even be considered a source of cocoa polyphenolisc

Studies assessing the influence of cocoa extract on blood flow note that 5-26g of dark cocoa contains 65-1,095mg of flavanols, and that within this range there are dose-dependent benefits to blood flow. This may be related to the recommended intake of cocoa flavanols (not so much cocoa 'extract', but the flavanols in particular) being in the range of 500-1000mg daily taken with meals.

If chocolate does not state the epicatechin content, consuming between 25-40 grams of a chocolate containing at least 85% cocoa by weight should be targeted (which is approximately 200kcal of chocolate). Dark chocolate that is 50% cocoa by weight may need up to twice the amount, around 400kcal or 100 grams to have the same effects while milk and white chocolate have too low a content of catechins to have any appreciable effect.

It is unsure if this is the optimal dose, but it appears to be more effective than lower doses.

This does not mean you should be pigging out on chocolate. Note the recommended dosage (especially the amount of dark chocolate that will satisfy for a reasonable dose).

Sol Orwell

Table of Contents:

Edit1. Sources and Composition

1.1. Origin and Composition

Cocoa extract (also referred to as Cocoa polyphenolics) are derived from Cacao seeds as a bitter bulk ingredient for commercial usage and supplementation[1] and as a general statement the phrase "Cocoa extract" refers to the collection of polyphenols found in dark chocolate which confer health benefits. Most of the polyphenols in cocoa are flavonoids, specifically the subset known as flavanols, and so the terms cocoa flavonoids and cocoa flavanols are sometimes used interchangeably with cocoa extract.

Cocoa extract refers to the polyphenolics or 'flavonoids' found in the plant which is eventually used to make chocolate, and these flavonoids are the molecules which mediate the vast majority of health benefits associated with chocolate consumption

Cocoa specifically contains (unsweetened cocoa powder unless otherwise specified):

  • (-)-epicatechin at 158.30mg/100g[2] with other sources suggesting a range of approximately 1.5-2.5mg/g.[3][4] (-)-epicatechin is lower in unsweetened baking chocolate (1-1.2mg/g[4]), dark chocolate (0.31-0.32mg/g[4]) semi-sweet baking chips (0.4-0.57mg/g[4]), milk chocolate (0.02-0.14mg/g[4]), and chocolate syrup (0.06-0.12mg/g[4])
  • (+)-catechin at 107.75mg/100g[2] almost always at lesser amounts than the (-)-epicatechin content in all chocolate products[4]
  • Procyanidins of varying chain length (all degrees of polymerization between a dimer and greater than 10 represented, favoring longer chains[4]) with their quantities reflecting the (-)-epicatechin content, unsweetened cocoa having a range of 18-22mg/g[4] with one source suggesting up to 44mg/g[3] baking chocolate between 10-14mg/g,[4] milk chocolate at 2mg/g or less,[4] and dark chocolate possessing 2-3mg/g total procyanidins[4]
  • (-)-Epicatechin-(2a-7)(4a-8)-epicatechin 3-O-galactoside at 5mg/100g[2]
  • Clovamide[5]
  • Cinnamtannin A2 at 33.17mg/100g[2] (catechin tetramer, currently thought to be exclusive to chocolate)[2]
  • Benzoic acid (0.06mg/100g)[2]
  • 3-Methylcatechol, 4-Methylcatechol, and 4-Ethylcatechol (all below 0.1mg/100g)[2] and catechol at 0.12mg/100g[2]
  • Quercetin (dark chocolate) at 25mg/100g[2]
  • Resveratrol (0.04mg/100g) and its 3,O-glucoside (0.1mg/100g) in dark chocolate[2]
  • Ferulic acid (dark chocolate) at 24mg/100g[2]
  • Nicotine at 0.12mcg/kg[6]

As a general statement, milk chocolate has little to no cocoa bioactives in it due to extensive processing while milk chocolate and chocolate syrup have negligible quantities. Standard dark chocolate, dutched chocolate, and semisweet baking chips are comparable good sources of catechins and procyanidins while unsweetened baking chocolate is better and unsweetened cocoa powder the best dietary source of these bioactives.[3][4]

Cocoa extract contains polyphenolics[7] ranging from 8.07 to 484.7mg/g (defatted cocoa powder)[8], which places it as one of the better dietary sources (alongside select herbs used as Spice, dark colored berries, and select vegetables)[2][7][9] being reported to sometimes contain up to 10% flavonoids.[10]

In regards to the polyphenolics, cocoa has a large amount of procyanidins (chains of catechin molecules) and a particularly high content of (-)-epicatechin relative to other catechin sources like green tea. Other phenolics such as resveratrol and quercetin seem to be lower than the catechin and procyanidin content and their relevance to cocoa powder is uncertain

Other components of cocoa extract include:

In regards to the low-weight psychoactives cocoa has a low amount of trace amines and xanthines such as caffeine which are not thought to be highly relevant following ingestion of chocolate, excluding potential MAOI interactions due to tyramine.

In general, cocoa is said to have around a 60/40 epicatechin:catechin ratio due to having higher levels of procyanidin B2 (epicatechin dimer) and procyanidin C1 (epicatechin trimer), with lower relative concentrations of procyanidin B1 (epicatechin-catechin) when compared to other procyanidin sources (Grape Seed Extract or Pycnogenol).[10] Natural cocoa products appear to have more total flavonoids than do other dark chocolate or cocoa products, with milk chocolate products having the least amount of flavonoids.[11]

1.2. Processing

As a general statement towards cocoa products and their flavonoid content, additional processing or manufacturing stages away from pure cocoa will gradually reduce the flavonoid content and total flavonoids tend to reflect the cocoa percentage of the product. The exception to this general rule would be dutch processing (alkalization) which can reduce the (-)-epicatechin, (+)-catechin, and total flavonoid content by upwards of 60%[12][13] with losses scaling with processing time[14] and affecting other components like procyanidins and Quercetin content.[12] Alkalization has been noted to increase the content of (-)-catechin relative to other processing methods,[13] but this molecule is not normally found in cocoa and is not linked to the health benefits of cocoa products.

Dutch processing, or alkalization of cocoa products, tends to result in an abnormally rapid loss of the beneficial compounds in cocoa products when compared to other processing methods.

1.3. Formulations and Variants

'Dark' chocolate, beyond the color and bitterness (from the xanthine molecules), refers to chocolate products which tend to be around 80% cocoa by weight and confer a significantly higher concentration of catechins and other bioactives.

Dark chocolate is the variant of chocolate with a significantly higher cocoa content and thus more of the beneficial compounds in chocolate, conferring benefits at a much lower oral dose

A particular brand of cocoa extract is known as 'chocamine' patented by RFI ingredients, which according to their website[15] the product specifications state that the powder is standardized to theobromine (greater than 12% by weight), caffeine (less than 0.5%), polyphenolics (greater than 5%) and contains added tapioca starch and some other spices (Ginger, allspice, Cinnamon, and vanilla powder in undisclosed amounts).

Chocamine is a theobromine rich cocoa powder

Edit2. Molecular Targets

2.1. Nitric Oxide

Nitric Oxide is a gasotransmitter involved in relaxing blood vessels, and increasing the activity of this molecule promotes blood flow and in certain instances may also reduce blood pressure.

Cocoa flavanols, particularly (-)-epicatechin, are known to improve blood flow in a way that is prevented by blocking the endothelial nitric oxide synthase (eNOS) enzyme[16] and while biomarkers of nitric oxide activity (such as the nitrate/Nitrate ratio) seem to be increased after (-)-epicatechin ingestion[17][18][19] the activity of nitric oxide donor molecules are unaffected[20][21][22][23] even in hypertensives.[24][25] This suggests that (-)-epicatechin must work via eNOS to promote nitric oxide formation but it is not working via antioxidative means (antioxidants such as Grape Seed Extract may preserve nitric oxide availability in instances of a high bodily oxidative state, but such a mechanism would augment the efficacy of nitric oxide donors), and this is likely traced back to an induction of the eNOS enzyme itself.

Both procyanidins and (-)-epicatechin in chocolate have been noted to induce eNOS activity in vitro[26][27] with isolated (-)-epicatechin being most active at a concentration of 1μM 20-40min after incubation,[26] similar to the time (-)-epicatechin acts in humans following oral ingestion. This increase in eNOS protein content is associated with increased phosphorylation of Ser-1177 and Ser-633 (dephosphorylation of Thr-495) secondary to calmodulin associated with eNOS due to PI3K activation.[26] Catechin appears to be 25% as potent as (-)-epicatechin with a mixture of both is less potent than pure epicatechin, which is thought to underlie why cocoa extract may be more potent than other catechin sources such as green tea.[26]

(-)-epicatechin appears to increase the protein content of the eNOS enzyme, which is the rate limiting step of making nitric oxide in blood vessels. By increasing the amount of this protein it allows more nitric oxide to be produced, which then act to enhance blood flow

The activation of eNOS from (-)-epicatechin is known to be calcium-independent[28][29] (increasing intracellular calcium can inhernetly activate eNOS[30]) but may act at the level of the cell membrane itself, since anchoring dextran to (-)-epicatechin (to restrict it from entering the cell[31]) does not prevent its actions in increasing nitric oxide signalling at a low concentration (100-500nM) nor in activating PI3K/Akt signalling to PDK1,[29] and elsewhere Akt has been noted to associated with heat shock protein 90 (HSP90) to form a complex which then travels to eNOS.[28]

It should also be noted that (-)-epicatechin can increase calcium release in a cell in a manner not related to eNOS activation,[32] and (+)-catechin also has affinity for this receptor but when both are introduced at the same time there may be less potency overall (thought to be from competitively inhibiting (-)-epicatechin binding).[29] This antagonism may be why dark chocolate, a relativly good source of (-)-epicatechin relative to (+)-catechin, may confer more benefits to blood flow than other plant sources of catechins.

(-)-epicatechin appears to act at the cell membrane via PI3K to then activate eNOS through heat shock proteins, but the specific receptor that it acts on in the cellular membrane is currently not known

2.2. Prostaglandins

Cocoa extract is said to influence prostaglandin activity in the human body secondary to the procyanidin content, and incubation of endothelial cells with a cocoa extract (49% procyanidins) at 2µg/mL resulted in decreaes in leukotrienes (LTC4, LTD4, and LTE4) with a doubling of PGI2.[33]

Oral ingestion of a chocolate product with a relatively high procyanidin content (0.4%) relative to a low content (0.009%) can acutely increase plasma prostacyclin by 32% and reduce total leukotrienes by 29%; there were also differences in (-)-epicatechin content in this study.[33]

This mechanism may underlie the anti-asthmatic actions of cocoa extract seen in rodents[34] as pharmaceuticals that act similar to prostacyclin (iloprost[35]) and agents that reduce leukotriene activity (pranlukast and zileuton[36]) confer anti-asthmatic activity, although the theophylline content of cocoa may also have an minor anti-asthmatic role[37] although it is underdosed (relative to its maximum efficacy) in cocoa products.

Edit3. Pharmacology

3.1. Absorption

In an acidic medium such as the stomach, cocoa polyphenolics (monomers such as (-)-epicatechin as well as procyanidins up to five monomers in length) appear to be structurally stable over the course of one hour[38] while administration of famotidine (H2 receptor antagonist which reduces stomach acidity) does not alter absorption rates of cocoa flavanols.[39]

The stomach does not appear to significantly influence the bioavailability or kinetics of the active cocoa molecules as they are stable in acid, so due to this enteric capsules are unlikely to exert unique benefits to supplementation

It is known that some dietary polyphenolics can have their absorption affected by food such as dietary fats[40][41] and there may be species differences.[41] As cocoa polyphenolics predominately consumed via food products their interactions with dairy products has been investigated, particularly due to how catechins in chocolate as structurally similar to those in tea which have been investigated for their interactions with milk.[42][43]

Ingestion of milk (250mL) alongside cocoa polyphenolics (70mg (-)-epicatechin) in healthy subjects does not appear to reduce absorption when measured after two hours, as the reduction of serum (-)-epicatechin glucuronide from 330+/-150nM in the water control to 273+/-138nM was not significant[44] while elsewhere in a rat study whole milk and heavy cream successfully lowered absorption relative to skim milk or water.[45] Gastric digestion rate does not appear to be influenced with milk relative to water (humans),[46] but it is possible that coingestion of milk (250mL) with flavanols can increase the time they spend in the body since it reduced how many are eliminated after 24 hours.[46]

One study has noted that coingestion of cocoa flavanols (via 125mg/kg cocoa powder) alongside about dietary carbohydrate (about 1g/kg carbohydrate via bread or sugar products) increased their bioavailability and subsequent AUC to 140% of cocoa alone (measured over 2.5 hours) while dietary fats and protein had no significant influence.[39]

As a general statement high fat meals may reduce absorption of the active molecules which high carb meals may increase their absorption, but practically speaking simply consuming cocoa flavanols via chocolates should have similar absorption rates when compared to isolated dietary supplements since said chocolates contain appreciable levels of both fats and carbohydrates

3.2. Transportation in Serum

Oral ingestion of drinks (with some additional macronutrients) containing cocoa was noted to increase serum epicatechin when measured at 120 hours post ingestion to approximately 500ng/mL (2g cocoa), 1,200ng/mL (5g), 3,500ng/mL (13g), and 8,000ng/mL (26g); data derived from graphs.[20]

Twice daily dosing of a cocoa drink (450mg flavanols at each dose) has failed to increase steady state catechin concentrations, thought to be related to a 3.6 hour half-life.[47]

Consumption of dark chocolate (40 grams) can be active in the blood stream two hours after consumption[48][49][50] near peak improvements in blood flow[23] and the (-)-epicatechin content appears to reach a concentration of around 118-121nM (0.11-0.12μM) in serum at this time point. Despite differences in effects between healthy controls and those with prooxidative conditions (hypertension, smoking) there do not appear to be differences in overall serum exposure to (-)-epicatechin.[49][50] Increasing the flavanol content in solid chocolate products causes dose-dependent increases in serum (-)-epicatechin.[51]

Chronic consumption of thrice daily dark chocolate ingestion (200 mg flavanols; (-)-epicatechin content not disclosed) has resulted in increased serum (-)-epicatechin at week six (78.28+/-64.35ng/mL), nine (46.23+/-41.52ng/mL), and twelve (57.68+/-46.54ng/mL) which very high variability.[52]

Consumption of low doses of dark chocolate (85% cocoa or greater) appears to result in low micromolar concentrations of (-)-epicatechin

In regards to procyanidins specifically, consumption of chocolate (0.375g/kg) containing 2.8% procyanidins (thus 10.5mg/kg procyanidins) has been noted to increased blood levels of procyanidin B2 to 100nM after two hours (Cmax) with approximately 50nM at both the one and four hour marks returning to baseline after eight hours.[53] A study elsewhere using the same chocolate product noted lower serum concentrations of 16+/-5nM after 30 minutes and a peak of 41+/-4nM after two hours.[54] in human plasma after the consumption of a flavanol-rich cocoa|published=2002 Oct|authors=Holt RR1, Lazarus SA, Sullards MC, Zhu QY, Schramm DD, Hammerstone JF, Fraga CG, Schmitz HH, Keen CL|journal=Am J Clin Nutr]

3.3. Neurological Distribution

Oral ingestion of (-)-epicatechin in mice at 125mg/kg bodyweight for 13 days has been noted to reach brain tissue, reaching a wet weight of 4.3ng/mg (-)-epicatechin and 1.5ng/mg 3'-O-methyl(-)-epicatechin; increasing the oral dose 10-fold resulted in brain concentrations of 7.3ng/mg and 16ng/mg respectively with all aforementioned numbers collectively referring to both free forms and conjugations.[55] There is no detectable 4'-O-methyl(-)-epicatechin in the brain following (-)-epicatechin ingestion[55] and the presence of the aforementioned two compounds has been confirmed elsewhere with shorter dosing periods.[56]

3.4. Metabolism

Ingestion of catechin from cocoa is subject to methylation to produce either 3'-O-methylcatechin or 4'-O-methylcatechin.[47]

Edit4. Neurology

4.1. Opioidergic Neurotransmission

Consumption of any food deemed palatable is able to increase opioidergic activity via a hypothalamic release of β-endorphin,[57][58] and chocolate has been implicated in opioidergic activity as one study noted a reduction (lessening) of a negative mood state associated with palatable chocolate but not unpalatable chocolate.[59]

4.2. Neurogenesis

In a mouse study assessing the actions of (-)-epicatechin (125-750mg/kg) on memory, despite an increase in memory formation being noted there did not appear to be any enhancement of newborn cellular survival in the hippocampus.[55]

It was noted that (-)-epicatechin increased vascularity of the DG subregion of the hippocampus, with no significant influence on CA1 or CA3 areas and without affecting the overall size of any area.[55] This effect was traced back to increased spine density in DG granule cells, and a few genes involved in learning were upregulated including synaptosomal-associated protein 25 (SNAP-25[60]) and kinesin family member 17 (Kif17[61]) alongside some involved in angiogenesis and some downregulation of inflammatory genes.[55]

4.3. Appetite

It appears that the scent of dark chocolate (relative to no inhalation of aromatics) is enough to potentially reduce appetite in women.[62]

4.4. Headaches and Blood Flow

In otherwise healthy young adults subject to a cognitive task, it appears that five days supplementation of 172mg cocoa flavanols (final dose 90 minutes before testing) increases blood oxygenation level-dependent (BOLD) contrast indicating increased cerebral oxygenation specifically in the prefrontal cortex, anterior cingulate cortex (ACC), and parietal cortex;[63] this was not accompanied by altered reaction times[63] which increased activity of the ACC is thought to result in.[64]

This was accompanied by an increase in blood flow that peaked two hours after supplementation (40% increase) and returned to baseline within six hours, suggesting the peripheral phenomena is linked to the neural.[63]

In otherwise healthy youth, cocoa flavanols appear to enhance blood flow to the brain and alongside the increase in blood flow there appears to be an increase in cerebral oxygenation

In a cohort of 37,103 men (Sweden) followed for 10.2 years found a decreased risk of stroke associated with chocolate with the highest quartile (25%) of consumption, with a median intake of 62.9g weekly, having an 0.83 relative risk compared to the no chocolate intake; the CI was 0.70-0.99.[65]

Epidemiological research a potential protective effect of cocoa flavanol ingestion against strokes when consumed in the diet

4.5. Anxiety and Stress

50g of dark chocolate (125mg (-)-epicatechin) given two hours prior to a psychosocial stressor in otherwise healthy men, relative to placebo chocolate, attenuated the rise of salivary cortisol and adrenaline with no influence on noradrenaline nor ACTH in a manner correlating with serum (-)-epicatechin.[66]

4.6. Depression and Mood

A possible mechanism for cocoa extract in interacting with mood may be its ability to prevent increases in the activity of the indoleamine 2,3-dioxygenase (IDO) enzyme during cellular inflammation as seen in vitro with concentrations that can be biologically relevant in the gut[67] as the increase in IDO mediates conversion of L-tryptophan into L-kynurenine via the L-kynurenine pathway;[68]) while beneficial for pathogen defense, excessive activation is thought to deplete L-tryptophan and thus reduce the amount available for serotonin biosynthesis.[69]

There is evidence for alterations in IDO activity in mood disorders (neopterin being a biomarker of IDO activity) such as seasonal affective disorder[70] and depression,[71] and the gut was mentioned specifically due to intestinal peyer's patches allowing exposure of oral bioactives to immune cells without absorption of said bioactive from the gut being required; the gut contains a high degree of bodily serotonin (upwards of 95%[72]) and the concentration of cacao flavanols required to inhibit IDO may be too high for serum activity.[67]

It is possible that cocoa components can exert an antiinflammatory effect on immune cells (macrophages and PMBCs) in the gut which, quite indirectly, exerts a mood elevating state related to serotonin. Although the current theory, the relevance of this signalling pathway to chocolate's effects on mood is not conclusively demonstrated

Consumption of chocolate alongside water has been noted to reduce (lessen) a negative mood state in response to a film without affecting positive or neutral mood states[59] and a later experiment noted that this was due to the palatability of chocolate as a chocolate product that was not deemed palatable failed to replicate the effects.[59]

Palatability per se is known to influence mood via opioid signalling, a release of β-endorphin from the hypothalamus, and can be mimicked in rats via sucrose feeding.[57][58]

There is an ability of chocolate to reduce negative mood states associated solely with how much users like to taste chocolate, since consumption of sweets that the consumer enjoys can per se improve mood state. It is likely any treat that the consumer likes can have similar effects

In older adults (40-65yrs), supplementation of 500mg cocoa polyphenols for 30 days (but not 250mg) was associated with an improved mood state mainly around calmness and contentness; 250mg was ineffective.[73]

4.7. Cognition

One study conducted on elderly persons with mild cognitive decline noted that cocoa flavanols were able to improve cognitive performance in a relatively dose dependent manner at both 520mg and 990mg daily, as assessed by Trail making tests and Verbal Fluency.[74] Elsewhere, there has been a failure of 250-500mg cocoa polyphenols for 30 days at improving attention (speed, continuity, and power of attention).[73]

4.8. Memory and Learning

In mice, ingestion of (-)-epicatechin at 500μg/g (0.05%; 125mg/kg in reference to body weight) of the diet for 42 days noted that consumption of epicatechin resulted in improvements in memory retention when given to mice and had more prominent effects when the mice experienced daily exercise;[55] this effect is nonsignificantly greater when given at six-fold the oral dose (750mg/kg) although higher doses of (-)-epicatechin do not have the same effects.[55]

250-500mg of cocoa flavonols daily for 30 days in otherwise healthy older adults has failed to improve quality of working memory or secondary memory[73] while elsewhere supplementation of 37g of 60% dark chocolate (400mg procyanidins) with 8 ounces of chocolate beverage containing a similar procyanidin content failed to improve working, moderate, or long-term memory as assessed by a battery of tests.[75]

Edit5. Cardiovascular Health

5.1. Absorption

Cocoa flavanols (procyanidins 2-10 monomers in length) may inhibit fat absorption, where the tested chocolate with the highest phenolic content (48.1%) inhibiting pancreatic lipase 25–53% at 20μM (more potency associated with longer chain procyanidins).[76] Phospholipase A2 was inhibited by 46–74% at 100μM.[76]

The procyanidins found in cocoa may be able to inhibit some fat absorption when coingested, although the practical significance of this information is not known (as procyanidins are commonly seen as a minor constituent of chocolate)

5.2. Cardiac Tissue

In mice given (-)-epicatechin at 1mg/kg twice daily for 15 days paired with physical exercise, the combination of those two factors relative to control appeared to result in an increase of mitochondrial proteins notably complex II of the electron transport chain and two markers of the mitochondrial membrane (porin and mitofilin).[77]

In regards to epidemiological research, there appears to be an association between higher chocolate intake and lower morbidity/mortality and risk for cardiovascular disease, as well as a protective effect as assessed by some other biomarkers (such as blood pressure).[78][79][80][81]

Rodent studies suggest benefical effects of (-)-epicatechin ingestion on the heart tissue itself in regards to promoting its energetic capacities at a relatively low human equivalent dose (0.08mg/kg twice daily), suggesting a possible protective effect of chocolate ingestion

One study looking at coronary circulation in healthy subjects given chocolate products noted that dark chocolate (550mg polyphenols) reported an increased coronary flow velocity reserve (CFVR) by 26% which did not occur after white chocolate ingestion, and this change did not seem to be dependent on changes in oxidation status of the blood or blood pressure.[82]

An increase in coronary blood flow has been noticed not related to blood oxidation status nor changes in blood pressure following ingestion of dark chocolate in otherwise healthy subjects

Some studies in humans have noted transient increases in blood pressure to a mild degree (4mmHg) when chocolate products are acutely ingested, which do not appear to be due to increases in resting blood pressure,[83] although acute ingestion of chocolate does not always cause this.[84][82] It is possible that the small xanthine content of chocolate (Caffeine and its metabolites theobromine and theophylline) accounts for this transient increase secondary to increased cardiac output (known to result from acute ingestion of xanthines[85]).

Chocolate products have the potential to acutely increase blood pressure, which may be due to the xanthine content rather than the flavanol content. This acute increase does not appear to result in a long-term increase in resting blood pressure

5.3. Red Blood Cells

Various polyphenols from cocoa appear to dose-dependently (2.5-40µM) protect red blood cells from lysis against oxidative stressors with longer chain procyanidins being more effective than monomers such as catechin at lower concentrations, with 1mg/mL of the mixed (acetone) extract slightly outperforming Vitamin C as a reference in vitro.[86]

Oral ingestion of 100mg of cocoa flavanols in rats (500-666mg/kg) appears to be enough to confer protection to red blood cells against AAPH (oxidative stressor)[86] and in humans given chocolate at 0.25, 0.375, and 0.50g/kg bodyweight (2.8% procyanidins and 1.2% monomers) noted that all doses protected red blood cells from hemolysis with the middle dose being most effective.[53]

5.4. Atherosclerosis

Aortic pulse wave velocity (PWV) is a measure used to assess aortic stiffness, a hardening of the aorta from calcification[87] which is the long-term target of Vitamin K for cardiovascular health[88] and is a good independent predictor of all-cause mortality at all ages[89] with anything that can reduce calcification thought to be protective.

When testing cocoa in otherwise healthy adults on this parameter, 10g of 75% dark chocolate daily for a month has resulted in a decrease in PWV of 5% (6.13+/-0.41m/s to 5.83+/-0.53m/s)[90] which is an effect not observed with acute usage of a higher dose of cocoa (100 grams) in the same demographic.[21]

It is possible that prolonged ingestion of cocoa products can result in a reduction in arterial calcification

In vitro, it appears that cocoa polyphenolics is able to inhibit LDL and vLDL oxidation[91][92] with similar or lesser potency to a similar concentration of Green Tea Catechins.[93] Despite the potency in vitro, studies assessing oral intake of cocoa flavanols have noted that diets containing the procyanidins (466mg) have caused only mild increases in lag time by 8%[94] or none at all[95][82] while large acute doses of flavanols (1,095mg) fail to appreciably influence LDL oxidation rates.[20]

While epicatechin and the procyanidins found in cocoa can technically reduce LDL oxidation rates due to their antioxidant properties, this is an effect demonstrated in vitro and does not appear to apply to oral ingestion possibly due to the low absorption of (-)-epicatechin relative to the dose required for direct antioxidant effects.

5.5. Blood Flow and Vasorelaxation

Ingestion of dark chocolate (30g of 70% cocoa) in prehypertensive subjects can increase the amount of nitric oxide in serum within 15 days by 54% as assessed by serum biomarkers.[96]

One study has also noted a reduction in vascular arginase activity,[97] the enzyme that degrades Arginine, thought to result in a refractory increase in L-arginine availability.

It is unsure if this is related to the antioxidant properties of cocoa (which are thought to be the mechanism by which agents like Grape Seed Extract or Vitamin C aid nitric oxide), as at least one study has noted increased blood flow independent of changes in oxidation of LDL (biomarker of oxidation).[20]

In regards to blood flow and circulatory health, cocoa flavanols are thought to improve circulation secondary to causing production of nitric oxide. This is likely due to epicatechin or other catechins directly stimulating the nitric oxide synthase enzyme

One study using oral ingestion of cocoa (450mg polyphenols and 87mg (-)-epicatechin) twice daily for two weeks in hypertensives noted an increase in insulin-induced artery width associated with supplementation[47] and improvements in blood pressure seen in hypertensives seem to coexist with improvements in insulin sensitivity[24][25] and β-cell function.[25] Studies that assess blood vessel diameter under resting conditions without insulin stimulation usually find no significant interaction between cocoa flavanols and vessel diameter.[98]

In type II diabetics on medication, daily ingestion of dark chocolate (963mg flavanols with 203mg (-)-epicatechin, taken in three divided doses) appears to cause a baseline increase in blood flow by 30%[23] with further spikes two hours after each oral dose lasting for four hours; this occured without improvements in glycemic control nor blood pressure.[23]

An increase in insulin-mediated vasodilation may also occur and contribute to the effects of chocolate on blood flow

In otherwise healthy young subjects, ingestion of a flavanol rich dark chocolate (100g) has acutely increased arterial diameter in both a resting and hyperemic state resulting in an increase in both flow-mediated vasodilation (FMD; 1.43%) and a decrease in the aortic augmentation index (ALX; 7.8%); these benefits occurred without alterations in plasma antioxidant status[21] and elsewhere have been noted to extend to an improvement in coronary flow velocity reserve (CFVR)[82] and are due to the flavanol content as a low flavanol content in the same style of study fails to have benefit.[95][82] If ingested for a month, healthy young adults may experience benefits to blood flow even with 10 grams of dark chocolate (75% cocoa) increasing FMD 9.31% relative to baseline (with no change in control).[90]

In otherwise healthy older individuals given drinks containing various dosages of cocoa (2, 5, 13, and 26g or placebo) and measured over the next 120 minutes, it was found that 5-26g cocoa (65-1,095mg total flavanols) was able to increase blood flow as assessed by FMD in a dose-dependent and linear manner, which correlated with serum polyphenolics, namely (-)-epicatechin[20] which appears to be the isomer of the catechins which is active[99] by increasing nitric oxide synthase activity [26] Oral ingestion of isolated (-)-epicatechin appears to mimick the effects seen with cocoa polyphenols.[100]

Dark chocolate has elsewhere been noted to be effective in diabetics,[23] smokers,[18][101] and those at risk for cardiovascular disease.[102][19][103] Overall this topic has been subject to meta-analysis assessing various health demographics and there did appear to be an average increase in blood flow assessed via FMD reaching 2% (95% CI or 1.6-2.39%) with comparable increases with a single dose (2.25%) or daily dosing for up to 12 weeks (1.76%) but slightly more benefits in those with elevated cardiovascular disease (CVD) risk factors (2.36%) than in healthy people (1.53%).[104]

It should be noted that some trials have failed to find improvements in blood flow[105] with at least one study noting some degree of 'response' that while hypertensive subjects noted a benefit in blood flow from 75g dark chocolate over a week, that those with worse symptoms (Framingham risk score and reactive hyperemeia index) had less efficacy.[103]

Appears to promote circulation in a dose-dependent manner, which correlates very well with serum (-)-epicatechin. Cocoa polyphenolics may be epicatechin prodrugs in regards to improving blood flow, and overall the increase in blood flow following cocoa ingestion appears to be somewhat reliable in regards to both health state (healthy or mildly diseased) and in regards to how long supplementation is continued

5.6. Blood Pressure

One of the mechanisms that cocoa flavanols possesses is thought to be reduction of blood pressure via inhibition of angiotension converting enzyme (ACE), establishing a role of cocoa flavanols as an ACE inhibitor[106] although its interactions with nitric oxide are also relevant to blood pressure (being the major mechanism related to blood flow),[107][108] potentially related to how an insulin-mediated interaction with nitric oxide can widen blood vessels after cocoa ingestion.[47]

Beyond blood flow, it has been thought that cocoa flavanols can reduce blood pressure by both related mechanisms (the increase in blood vessel width related to nitric oxide) but also by other possible means such as ACE inhibition

Short term studies have noted minor transient increases in blood pressure (alongside an increase in blood flow)[83][20] or reductions in blood pressure,[74] while in hypertensives there is similar variability with one study noting a decrease in ambulatory blood pressure associated with dark chocolate consumption (100 grams for two weeks)[24] while a similar study using the dose of cocoa via beverage in hypertensives failed to find any effect.[47] When an increase in blood pressure occurs, it appears to be transient and mild (4mmHg[83]) and does not appear to be associated with an increase in basal or resting blood pressure.[83]

In healthy individuals (young adult soccer players) consumption of a low dose of flavanols (168mg) via chocolate for one week appeared to be associated with minor reductions in systolic (5%), diastolic (7%) and mean (6%) blood pressure relative to cream chocolate control.[109]

One meta-analysis of 20 studies[110] concluded that consumption of cocoa products (usually dark chocolate or cocoa supplementation) is associated with a small 2-3mmHg reduction of systolic blood pressure.

While benefits to blood pressure appear to be more variable than benefits to blood flow, there may be a minor reduction in blood pressure with chronic consumption of cocoa flavanols.

5.7. Platelets and Viscosity

(-)-epicatechin is known to exert a protective effect on fibrinogen against the free radical known as peroxynitrate (ONOO-) in vitro at 1-10μM,[111] as (-)-epicatechin can effectively sequester ONOO-[112] which is known to modify the structure of proteins in excess concentrations. Epicatechin can reduce this modification to proteins in general[111] and when it does this for fibrinogen the result is less ability to clot the blood.[113]

In vitro it seems that epicatechin can prevent oxidative changes to a major protein involved in blood clotting which should result in cocoa flavonoids being able to preserve the clotting response; this mechanism is not yet tested in humans

In otherwise healthy men who consume dark chocolate (50g) two hours prior to a psychosocial test known to promote blood clotting[114][115] it appears that consumption of the dark chocolate is associated with less biomarkers of clotting (D-Dimer) than white chocolate not containing flavonoids;[116] this is not related to changes in catecholamines such as adrenaline which were unaffected.[116]

40 grams of dark (85% cocoa) chocolate appears to be capable of reducing platelet viscosity in smokers when measured two hours after consumption, an effect accompanied by reduction in oxidation (48% reduction in ROS), the prostaglandin 8-iso-PGF2α (10%) and NOX2 activity (22%)[50] and unique to smokers as it did not occur in nonsmoking controls;[50] this may be related to a known higher baseline oxidation and NOX2 activity in smokers.[50][49] Elsewhere in healthy nonsmoking individuals given 700mg cocoa flavonoids daily for a week[117] or 900mg total polyphenolics acutely,[118][119] the platelets removed from subjects appear to be resistant to aggregation when stimulated by clotting factors such as Arachidonic acid, ADP, or adrenaline with some differences between the two sexes (although both find overall anticlotting actions).[120]

The concentration of (-)-epicatechin required to increased nitric oxide concentration in a platelet, approximately 0.1μM (100nM),[49] appears to be feasible in the blood following ingestion of 40g dark chocolate.[49][50] Comparatively speaking, the effects seem to be similar to aspirin in concept although 900mg cocoa polyphenolics (total (-)-epicatechin and procyanidins) is less potent than a baby aspirin (81mg) when both are taken acutely.[119]

The increased aggregative potential of platelets seen in prooxidative states (studies assessing smokers) seems to be remedied with ingestion of dark chocolate while not necessarily affecting otherwise healthy states, but may also extend to instances of acute stress. In this sense, cocoa flavonoids seem to have a conditional anticlotting effect with a potency lesser than aspirin

5.8. Triglycerides

One meta-analysis looking at interventions using cocoa products of variable time lengths (2-12 weeks) noted that overall there was no significant reduction of triglycerides, as the apparent reduction of 5.06mg/dL was too variable (with the 95% CI ranging between a reduction of -13.45mg/dL to an increase of 3.32mg/dL);[121] the studies assessed that had the largest observed reductions[109][25][24] tended to also have nonsignificant results due to excess variability between subjects.

5.9. Cholesterol

A small meta-analysis on the ingestion of cocoa products[121] assessing five studies on healthy persons[75][122][109][95][94] with the other five being on hypertensive,[47][24] overweight or obese,[123][98] or diabetic subjects[23] found that ingestion of variable doses of cocoa flavanols (88-963mg) or procyanidins (213-754mg) was indicative of a reduction in LDL cholesterol 5.90mg/dL (95% CI of a 1.32-10.47mg/dL reduction) whereas HDL-C and total cholesterol did not appear to be significantly affected overall.[121]

Edit6. Interactions with Glucose Metabolism

6.1. Glycation

In instances of acute hyperglycemia (following an oral glucose tolerance test), subjects who ingested 100g of dark chocolate for three days appeared to not have any increase in blood pressure or impairments to blood flow that were seen with the white chocolate control.[124]

6.2. Insulin

Ingestion of 100g chocolate in otherwise healthy individuals does not appear to increase insulin secretion in response to an oral glucose tolerance test.[124]

One study using oral ingestion of cocoa (450mg polyphenols and 87mg (-)-epicatechin) twice daily for two weeks in hypertensives noted an increase in insulin-induced artery width associated with supplementation.[47]

6.3. Insulin Sensitivity

Insulin is known to promote an increase in Nitric Oxide bioavailability, which then acts to augment insulin-mediated glucose uptake forming a reciprocal relationship.[125][126] Due to the ability of (-)-epicatechin to promote nitric oxide bioavailability and it being known to increase insulin-mediated vasodilation[47] it's influence on glucose uptake as a result of enhanced insulin signalling has been investigated.

Healthy adults given 100 grams of dark chocolate (500mg total flavanols) daily for 15 days, relative to white chocolate control, have been noted to experience an increase in insulin sensitivity (HOMA, QUICKI, and ISI) when subject to a glucose load; the average insulin sensitivity index (ISI) appeared to be near doubled with dark chocolate (15.18+/-7.69) relative to white chocolate control (7.4+/-3.5).[122] An improvement in insulin sensitivity (via HOMA2) has also been noted with overweight adults given 451mg flavanols daily for 12 weeks in a manner that did not interact with modest physical exercise[98] while three days supplementation of 100g dark chocolate in otherwise healthy adults is perhaps too short of a time to have an appreciable effect on insulin sensitivity.[124]

Elsewhere, essential hypertensives given a cocoa beverage with 450mg flavanols (87mg (-)-epicatechin) for two weeks failed to see any improvement in insulin sensitivity during a hyperinsulinemic isoglycemic glucose clamp despite an increase in insulin-mediated vasodilation[47] although the same (-)-epicatechin dose via 100 grams of dark chocolate in a similar population improved insulin sensitivity during an oral glucose tolerance test alongside improvements in blood flow and pressure in both those with unimpaired insulin sensitivity[24] and insulin resistant hypertensives (1009mg total polyphenolics with 111mg epicatechin daily for 15 days).[25]

Edit7. Fat Mass and Obesity

7.1. Adipokines

Short term ingestion of dark chocolate (100g of 70% cocoa) in overweight women for one week has been noted to not have an effect on circulating interleukins IL-1α, IL-1β, or IL-6 but reduced concentrations of interleukin 1 receptor antagonist (IL-1Ra) by 33+/-4% relative to baseline;[127] IL-1Ra is known to be antiinflammatory via preventing the actions of IL-1α and IL-1β[128] but is also secreted in high amounts from visceral fat[129] where it is thought to be a biomarker for leptin resistance.[130] Due to a reduction in waist circumference seen in this sample of women,[127] it was thought to be indicative of leptin resensitivity rather than a proinflammatory mechanism per se.

Currently hypothesized to influence leptin metabolism in subjects with visceral fat due to influences on a biomarker of leptin sensitivity, but no studies have currently assessed leptin levels or sensitivity with prolonged cocoa ingestion

7.2. Lipolysis

Fat oxidation rates during modest exercise in overweight adults who previously had 451mg cocoa flavanols for 12 weeks (alongside an exercise program) does not appear to alter fat oxidation rates relative to either exercise without the flavanols, flavanols without exercise, or neither.[98]

7.3. Weight

Studies in overweight or obese adults that incorporate dark chocolate into their dietary regimen have failed to note any inherent weight loss effect of 50g dark chocolate (2135mg polyphenolics) over four weeks despite benefits to blood flow.[131]

Edit8. Skeletal Muscle and Physical Performance

8.1. Myokines

A pilot study using six middle aged subjects (41+/-5 years) of average weight given 1mg/kg (-)-epicatechin twice a day for one week was able to increase the follistatin to myostatin ratio by 49.2+/-16.6%; exact levels of myostatin and follistatin in these subjects before and after supplementation was not disclosed.[132]

When (-)-epicatechin is fed orally to mice at 2mg/kg daily (in two divided doses of 1mg/kg) for two weeks, the 18% increase in myostatin and 30% decrease in follistatin which normally occurs are prevented while in young mice given the same dose of (-)-epicatechin reduces myostatin 15% with no influence on follistatin.[132]

8.2. Bioenergetics

Cocoa powder (6.43% (-)-epicatechin content and 3.54% procyanidin B2) at 50mg/kg daily in mice for two weeks has been noted to reduce blood glucose thought to be secondary to an increase in fat oxidation in skeletal muscle,[133] a hypothesis supported by an increase in resting energy expenditure (RER) and expression of CPT2 and UCP1 proteins independent of any changes in locomotor activity.[133]

These beneficial bioenergetic changes at the level of the mitochondria have been noted in a preliminary study of five humans who had impaired mitochondria function and structure (type II diabetic and with heart failure) when given 100 mg (-)-epicatechin daily for three months.[134] An improvement of mitochondria cristae has been noted both in mice with poor oxidative metabolism in skeletal muscle[135] as well as the aforementioned human study.[134]

Consumption of 100g dark chocolate (70% cocoa) has been noted to nonsignificantly increase plasma non-esterified fatty acids (NEFA) when consumed acutely two hours prior to cycling exercise relative to milk chocolate[136] and to increase serum free fatty acids when 40g is consumed before a 90 minute cycle,[137] with no obervable changes in total triglyceride content[137] or in biomarkers of metabolic rate or fat oxidation rates.[136][137]

It is known that consumption of fatty acids per se can increase total free fatty acids in serum during exercise even without changes in performance[138] although the differing effects between dark chocolate and cocoa-free control with a similar fatty acid profile[137] suggest a role for the catechins.

8.3. Muscular Endurance

Oral ingestion of 1mg/kg (-)-epicatechin twice daily in one year old mice (C57BL/6N), an age where physical performance tends to decrease,[139] for 15 days alongside exercise noted improvements in duration and distance until failure relative to exercise alone;[77] ingestion of (-)-epicatechin at this dose without exercise failed to have any effect when compared to control.[77]

In rats that are bred for low endurance performance (LCR rats[140][141] with defects in aerobic metabolism[142]) the same dose of (-)-epicatechin for a month appeared to increase mitochondrial cristae, angiogenesis, and biogenesis of mitochondria which are thought to be the mechanisms underlying improvements in physical performance (although it was not directly measured in this study[135]). This study noted a 40% increase in expression of VEGF-A, an angiogenic factor, which was normalized 15 days after (-)-epicatechin cessation.[135]

It is further thought to be relevant to glycolytic muscle (in rats, the plantaris muscle) since this muscle type differs in these selectively bred rats relative to those bred for high performance[143] (the soleus muscle does not appear to differ[143][144]) and the parameters (-)-epicatechin appears to benefit, mitochondrial activity and angiogenesis, are inherently lower in these muscle.[145]

One study in mice specifically looking at detraining noted that administration of 1mg/kg twice daily (-)-epicatechin for 15 days of rest in trained mice prevented improvements in exercise performance from being lost during prolonged rest, which was associated with preventing the exercise-induced increases in complex III and IV of the mitochondria from being reduced.[146]

In soccer players, consumption of chocolate (containing 168mg flavanols; 39mg (-)-epicatechin) once daily for a week was associated with improvements in oxidative status yet failed to influence their performance during sporting (via self-report during the week long intervention).[109]

8.4. Muscular Power Output

(-)-epicatechin at a dose where it improved endurance performance in mice after 15 days (1mg/kg twice daily) failed to have any influence on force output or acute contractility (when tested ex vivo) despite being more resistant to fatigue from repeated contractions[77] whereas elsewhere 1mg/kg twice daily in sedentary middle aged adults (42 years of age) appeared to slightly increase grip strength by 7% relative to baseline; no placebo control was used in this latter study.[132]

8.5. Immunological Interactions

Dark chocolate (100g of 70% cocoa) given to otherwise healthy men acutely before exercise noted that the increase in plasma (-)-epicatechin was associated with an increase in total antioxidant capacity of the blood immediately before and after exercise but failed to cause any differences in IL-6 concentrations relative to milk chocolate or baseline or in oxidative burst of neutrophils.[136]

Edit9. Inflammation and Immunology

9.1. Immunosuppression

In overweight men given 70g high flavanol chocolate (1078mg; 349mg (-)-epicatechin), leukocyte adhesion factor sICAM-1 increased relative to the group given 70g of standard 58% cocoa (259mg; 97mg (-)-epicatechin) while sICAM-3 increased acutely in both groups;[51] when supplementation persisted for four weeks both these adhesion factors decreased with no differences between chocolates in a fasted state or in response to a high fat test meal.[51]

9.2. Interleukins

Cocoa procyanidins have been noted to have no influence on IL-5 secretion in PMBCs at rest, but augment the increase when under stimulation from PHA.[147]

9.3. Macrophages

Cacao extracts have been noted in vitro to downregulate inflammatory cytokines from macrophages including MCP-1, TNF-α, and IL-6 with a potency greater than a similar concentration of pure (-)-epicatechin[148] (similar antiinflammatory effects seen in whole blood[149]) other studies to find similar actions in macrophages have noted efficacy with the isolated cocoa constituent clovamide when both studies are using LPS as an inflammatory stimuli;[5] when LPS is not present, procyanidins from cocoa have been noted to possess the ability to increase the secretion of IL-1, IL-6, and TNF-α in PMBCs[150][151] with more potency seen with the longer chain flavanols.[151]

It has been suggested[152] that these constituents are acting via their antioxidant capacities, since there are REDOX sensitive pathways since antioxidants in general may suppress macrophage activation (a major locus, NF-kB, is suppressed by antioxidants[153] and (-)-epicatechin has been noted to suppress NF-kB[149]).

Similar to most antioxidants which are REDOX capable (antioxidant or oxidant dependent on cellular context) (-)-epicatechin and other flavanols in cocoa may have antiinflammatory effects when other inflammatory stimuli are present while inherently having some stimulatory action on macrophages at rest

9.4. T Cells

The indoleamine 2,3-dioxygenase (IDO) enzyme mediates the breakdown of L-tryptophan into L-kyurenine and various metabolites (known as the kynurenine pathway[68]) is induced by IFN-γ in T cells (as well as macrophages, less in B cells and HUVECs[154][155]) during inflammation and appears to have a role in viral and bacterial infections.[156][157] IDO is also thought to be a potential link between depression and inflammation as it hypothetically depleted L-tryptophan stores which could have been used to synthesize serotonin,[69] and IDO activity (assessed by neopterin as a proxy measure) is thought to increase with oxidation as the two are correlated in immune cells[158] and in vivo.[159]

In regards to cocoa, the degradation of L-tryptophan (via IDO) in PMBCs appeared to be greatly suppressed to a near absolute degree at a concentration of 5µg/mL when activated by mitogens; THP-1 cells were wholly unaffected.[67]

9.5. Allergies

When tested in guinea pigs sensitized to an antigen (ovalbumin) who were given unsweetened cocoa at one of two doses (300 of 600mg/kg) for 35 days with the final dose an hour before antigen presentation, it was noted that there was a dose-dependent anti-allergic action of supplementation relative to water (as control).[34]

9.6. Virological Interactions

The structure of epicatechin, found in chocolate but is one of the main four Green Tea Catechins, has been found to normalize adverse changes (by the Tat protein; elevated in HIV) with proBDNF and BDNF, which exerted neuroprotective effects against the side-effects of HIV with greater potency than Resveratrol.[160]

Edit10. Interactions with Hormones

10.1. Corticosteroids

(-)-epicatechin is thought to interact with cortisol as the antiinflammatory effects of cortisol are somewhat mitigated by oxidative stress, and the antioxidant abilities of (-)-epicatechin (1-50µM) can preserve the actions of cortisol in isolated monocytes.[161]

Edit11. Peripheral Organ Systems

11.1. Intestines

A diet high in cocoa flavanols (494mg with 89mg epicatechin and 21mg catechin) daily for four weeks has been noted to increase the bacterial count of bifidobacterial, enterococcus, and lactobacilli strains in the intestines while decreasing clostridia as assessed by fecal examination.[162] This study also noted decreases in blood pressure and C-reactive protein, with the latter correlated to changes in lactobacilli,[162] and the suppression of clostridia histolyticum noted with cocoa flavanols has been noted with isolated (+)-catechin[163] and other Green Tea Catechins.[164]

11.2. Liver

In subjects with liver cirrhosis, eating a meal can result in low blood pressure due to a phenomena known as the hepatic venous pressure gradient (HPVG); due to hypertension in the liver, more blood is redirected to the liver to accomodate food intake resulting in a reduction in peripheral blood pressure.[165][166] This is likely due to decreased nitric oxide bioavailability in the liver and is exacerbated by excess oxidation, with both nitric oxide donors[167] and antioxidants[168] having been at times implicated in being therapeutic.

In these subjects, a liquid meal that contains dark chocolate (85% cocoa) appeared to be associated with less of a post-meal increase in the HPVG relative to a meal without flavonoids thought to be related to improved liver circulation, although despite the hypothesis and benefits to HPVG when measuring portal vein and total blood flow as well as hepatic artery blood flow there did not appear to be any differences between groups;[169] regardless, the peripheral gradient was about halved with dark chocolate and peripheral arterial pressure increased without changes in heart rate.[169]

The post meal reduction in blood pressure that subjects with cirrhosis experience can be attenuated by ingestion of polyphenolic containing dark chocolate products

11.3. Kidneys

In diabetic rats, injections of 15-30mg/kg (-)-epicatechin for 35 days appeared to dose-dependently attenuate lipid peroxidation relative to diabetic control; there was no effect of (-)-epicatechin on mice without diabetes and this was associated with a preservation of superoxide dismutase (SOD) activity.[170]

In otherwise healthy subjects given 1g/kg dark chocolate (70% cocoa) and measured two hours later, it appears that supplementation increased the oxygenation of corticol and medullary tissue in the kidneys compared to the control of white chocolate; this effect was correlated with the serum (-)-epicatechin content.[171]

11.4. Eyes

Acute ingestion of 40g dark chocolate in glaucoma patients and normal controls failed to influence blood pressure and intraocular pressure (IOP) any more than white chocolate control,[172] and while there appeared to be increased venule dilation in response to a flicker test this was only present in controls (without glaucoma) given dark chocolate.[172]

Edit12. Longevity and Life Extension

12.1. Mitochondria and Cellular Structures

Oral administration of 1mg/kg (-)-epicatechin to aged mice appears to attenuate some of the age-related changes in antioxidant proteins and some proteins involved in mitochondrial biogenesis (sirtuins) and reduce the senescence-associated biomarker β-galactosidase compared to aged control.[173]

Edit13. Interactions with Aesthetics

13.1. Skin

Cocoa flavanols have been investigated for their effects on the skin due to being minor constituents of cocoa butter, a fat derived from the cacao plant used topically in many skin care products, as trace flavanols remain in the butter conferring aromatic and antioxidant (preservative) properties.

In otherwise healthy women given either ten grams of chocolate with a low flavanol content (200mg) thrice daily for a total of 600mg flavanols or control chocolate failed to observe any differences in photoprotection as assessed by minimum erythema dose (MED).[52]

600mg flavanols daily via three doses of dark chocolate (200mg each) has been noted to slightly increase skin elasticity on the temple, but not arms, relative to control chocolate.[52] There were no observed changes in skin hydration status between groups.[52]

In adult men with a history of acne given either chocolate (in the form of unsweetened capsules) or a visually identical placebo in varying doses (1-6oz) for one week appeared to increase number of lesions relative to placebo.[174] This effect may be limited to the acne prone, as a pilot study using 39g chocolate bars over a week only noted a third of subjects increased lesion count[175] with another pilot study using higher doses (340g or 12oz of milk chocolate) over week in acne prone men noting a similar 4-7 day time course for exacerbation of acne lesions.[176]

Edit14. Interactions with Medical Conditions

14.1. Peripheral Artery Disease (PAD)

Cocoa extract is thought to be beneficial for periperal artery disease (PAD) due to its ability to enhance blood flow, secondary to (-)-epicatechin and related catechins increasing Nitric Oxide (NO) signalling via reducing the activity of NOX-2 in vitro, requiring a mixture of catechins rather than isolated (-)-epicatechin.[48] NOX-2 is a catalytic subunit of NADPH oxidase which produces free radicals, and can cause a reduction of NO signalling as the oxidation promotes conversion into peroxynitrate indirectly reducing NO availability[177] and dark chocolate is well known to suppress NOX2 activity and increase blood flow in instances of low blood flow associated with oxidation[49][50] which also characterizes PAD.[178]

Dark chocolate, due to the catechins specifically in regards to a high (-)-epicatechin content, are known to acutely benefit any condition where blood flow is impaired associated with elevated oxidation. Peripheral artery disease is one of these conditions

In people diagnosed with PAD given chocolate, ingestion of a single dose of dark chocolate (40 grams of 85% cocoa) but not milk chocolate (40g of 35% cocoa) resulted in an increase in serum epicatechin and other catechins, which was thought to underlie the benefits seen in walking distance (11% increase) and walking time (15% increase) relative to themselves as control.[48]

In contrast to the aforementioned, ingestion of 50 grams of dark chocolate in PAD sufferers without a walking test has failed to influence blood flow at rest and failed to influence any measured circulatory/microcirculatory parameters relative to baseline; white chocolate also ineffective.[179]

14.2. Alzheimer's

It is known that cognitive aging is related to a reduction in blood flow to the brain[180][181] thought to at least in part underlie associations between dietary flavonoids and reduced risk of cognitive decline seen in both epidemiological research on dementia[182] and rodent interventions and neural susceptability to damage;[183] this potential benefit is similar to what is hypothesized for dietary Nitrate intake, and due to (-)-epicatechin increasing cerebral blood flow[63] it as well as its food source (dark chocolate) are thought to have a protective role.[184] At least two of the brain regions that (-)-epicatechin can increase blood flow to, the prefrontal and parietal cortices,[63] seem to have less blood flow to them during Alzheimer's disease.[185][186]

Edit15. Nutrient-Nutrient Interactions

15.1. Chocolate

When tested in vitro in regards to suppressing NOX2 activity (a mechanism which results in increased blood flow in pro-oxidative states) and increasing secretion of VCAM-1 and E-selectin, concentrations of (-)-epicatechin, EGCG, and catechin that are found in serum after ingestion of 40 grams of dark chocolate (a concentration range of 0.1-10μM) were effective when used together while no constituent was effective on its own; this suggests additive or synergistic effects of catechin constituents in chocolate relative to pure (-)-epicatechin.[48]


  1. Crozier SJ, et al. Cacao seeds are a "Super Fruit": A comparative analysis of various fruit powders and products. Chem Cent J. (2011)
  2. Phenol-Explorer: an online comprehensive database on polyphenol contents in foods
  3. Gu L1, et al. Procyanidin and catechin contents and antioxidant capacity of cocoa and chocolate products. J Agric Food Chem. (2006)
  4. Miller KB1, et al. Survey of commercially available chocolate- and cocoa-containing products in the United States. 2. Comparison of flavan-3-ol content with nonfat cocoa solids, total polyphenols, and percent cacao. J Agric Food Chem. (2009)
  5. Zeng H1, et al. Anti-inflammatory properties of clovamide and Theobroma cacao phenolic extracts in human monocytes: evaluation of respiratory burst, cytokine release, NF-κB activation, and PPARγ modulation. J Agric Food Chem. (2011)
  6. Müller C1, et al. Determination of caffeine, myosmine, and nicotine in chocolate by headspace solid-phase microextraction coupled with gas chromatography-tandem mass spectrometry. J Food Sci. (2014)
  7. Manach C, et al. Polyphenols: food sources and bioavailability. Am J Clin Nutr. (2004)
  8. Determination of Flavanol and Procyanidin (by Degree of Polymerization 1-10) Content of Chocolate, Cocoa Liquors, Powder(s), and Cocoa Flavanol Extracts by Normal Phase High-Performance Liquid Chromatography: Collaborative Study
  9. Habauzit V, Morand C. Evidence for a protective effect of polyphenols-containing foods on cardiovascular health: an update for clinicians. Ther Adv Chronic Dis. (2012)
  10. Ghosh D, Scheepens A. Vascular action of polyphenols. Mol Nutr Food Res. (2009)
  11. Ramirez-Sanchez I, et al. Fluorescent detection of (-)-epicatechin in microsamples from cacao seeds and cocoa products: Comparison with Folin-Ciocalteu method. J Food Compost Anal. (2010)
  12. Andres-Lacueva C1, et al. Flavanol and flavonol contents of cocoa powder products: influence of the manufacturing process. J Agric Food Chem. (2008)
  13. Hurst WJ1, et al. Impact of fermentation, drying, roasting and Dutch processing on flavan-3-ol stereochemistry in cacao beans and cocoa ingredients. Chem Cent J. (2011)
  14. Miller KB1, et al. Impact of alkalization on the antioxidant and flavanol content of commercial cocoa powders. J Agric Food Chem. (2008)
  15. Chocamine
  16. Fisher ND, et al. Flavanol-rich cocoa induces nitric-oxide-dependent vasodilation in healthy humans. J Hypertens. (2003)
  17. Taubert D, et al. Effects of low habitual cocoa intake on blood pressure and bioactive nitric oxide: a randomized controlled trial. JAMA. (2007)
  18. Heiss C, et al. Acute consumption of flavanol-rich cocoa and the reversal of endothelial dysfunction in smokers. J Am Coll Cardiol. (2005)
  19. Heiss C, et al. Vascular effects of cocoa rich in flavan-3-ols. JAMA. (2003)
  20. Monahan KD, et al. Dose-dependent increases in flow-mediated dilation following acute cocoa ingestion in healthy older adults. J Appl Physiol. (2011)
  21. Vlachopoulos C, et al. Effect of dark chocolate on arterial function in healthy individuals. Am J Hypertens. (2005)
  22. Heiss C, et al. Sustained increase in flow-mediated dilation after daily intake of high-flavanol cocoa drink over 1 week. J Cardiovasc Pharmacol. (2007)
  23. Balzer J, et al. Sustained benefits in vascular function through flavanol-containing cocoa in medicated diabetic patients a double-masked, randomized, controlled trial. J Am Coll Cardiol. (2008)
  24. Grassi D1, et al. Cocoa reduces blood pressure and insulin resistance and improves endothelium-dependent vasodilation in hypertensives. Hypertension. (2005)
  25. Grassi D1, et al. Blood pressure is reduced and insulin sensitivity increased in glucose-intolerant, hypertensive subjects after 15 days of consuming high-polyphenol dark chocolate. J Nutr. (2008)
  26. Ramirez-Sanchez I, et al. (-)-epicatechin activation of endothelial cell endothelial nitric oxide synthase, nitric oxide, and related signaling pathways. Hypertension. (2010)
  27. Leikert JF, et al. Red wine polyphenols enhance endothelial nitric oxide synthase expression and subsequent nitric oxide release from endothelial cells. Circulation. (2002)
  28. Ramirez-Sanchez I1, et al. (-)-Epicatechin-induced calcium independent eNOS activation: roles of HSP90 and AKT. Mol Cell Biochem. (2012)
  29. Moreno-Ulloa A1, et al. Cell membrane mediated (-)-epicatechin effects on upstream endothelial cell signaling: evidence for a surface receptor. Bioorg Med Chem Lett. (2014)
  30. Taylor MS1, et al. Dynamic Ca(2+) signal modalities in the vascular endothelium. Microcirculation. (2012)
  31. Intraluminal-restricted 17β-estradiol exerts the same myocardial protection against ischemia/reperfusion injury in vivo as free 17β-estradiol
  32. Ramirez-Sanchez I1, et al. (-)-Epicatechin induces calcium and translocation independent eNOS activation in arterial endothelial cells. Am J Physiol Cell Physiol. (2011)
  33. Schramm DD1, et al. Chocolate procyanidins decrease the leukotriene-prostacyclin ratio in humans and human aortic endothelial cells. Am J Clin Nutr. (2001)
  34. Awortwe C1, et al. Unsweetened natural cocoa has anti-asthmatic potential. Int J Immunopathol Pharmacol. (2014)
  35. Jones RL1, et al. Relaxant actions of nonprostanoid prostacyclin mimetics on human pulmonary artery. J Cardiovasc Pharmacol. (1997)
  36. Misson J1, Clark W, Kendall MJ. Therapeutic advances: leukotriene antagonists for the treatment of asthma. J Clin Pharm Ther. (1999)
  37. Hansel TT1, et al. Theophylline: mechanism of action and use in asthma and chronic obstructive pulmonary disease. Drugs Today (Barc). (2004)
  38. Rios LY, et al. Cocoa procyanidins are stable during gastric transit in humans. Am J Clin Nutr. (2002)
  39. Schramm DD1, et al. Food effects on the absorption and pharmacokinetics of cocoa flavanols. Life Sci. (2003)
  40. Lesser S1, Cermak R, Wolffram S. Bioavailability of quercetin in pigs is influenced by the dietary fat content. J Nutr. (2004)
  41. Visioli F1, et al. Hydroxytyrosol excretion differs between rats and humans and depends on the vehicle of administration. J Nutr. (2003)
  42. Hollman PC1, et al. Addition of milk does not affect the absorption of flavonols from tea in man. Free Radic Res. (2001)
  43. van het Hof KH1, et al. Bioavailability of catechins from tea: the effect of milk. Eur J Clin Nutr. (1998)
  44. Roura E1, et al. Milk does not affect the bioavailability of cocoa powder flavonoid in healthy human. Ann Nutr Metab. (2007)
  45. Gossai D1, Lau-Cam CA. Assessment of the effect of type of dairy product and of chocolate matrix on the oral absorption of monomeric chocolate flavanols in a small animal model. Pharmazie. (2009)
  46. Mullen W1, et al. Milk decreases urinary excretion but not plasma pharmacokinetics of cocoa flavan-3-ol metabolites in humans. Am J Clin Nutr. (2009)
  47. Muniyappa R1, et al. Cocoa consumption for 2 wk enhances insulin-mediated vasodilatation without improving blood pressure or insulin resistance in essential hypertension. Am J Clin Nutr. (2008)
  48. Loffredo L1, et al. Dark chocolate acutely improves walking autonomy in patients with peripheral artery disease. J Am Heart Assoc. (2014)
  49. Loffredo L1, et al. NOX2-mediated arterial dysfunction in smokers: acute effect of dark chocolate. Heart. (2011)
  50. Carnevale R1, et al. Dark chocolate inhibits platelet isoprostanes via NOX2 down-regulation in smokers. J Thromb Haemost. (2012)
  51. Esser D1, et al. Dark chocolate consumption improves leukocyte adhesion factors and vascular function in overweight men. FASEB J. (2014)
  52. Mogollon JA, et al. Chocolate flavanols and skin photoprotection: a parallel, double-blind, randomized clinical trial. Nutr J. (2014)
  53. Zhu QY1, et al. Influence of cocoa flavanols and procyanidins on free radical-induced human erythrocyte hemolysis. Clin Dev Immunol. (2005)
  54. Procyanidin dimer B2 [epicatechin-(4beta-8)-epicatechin
  55. van Praag H1, et al. Plant-derived flavanol (-)epicatechin enhances angiogenesis and retention of spatial memory in mice. J Neurosci. (2007)
  56. Abd El Mohsen MM1, et al. Uptake and metabolism of epicatechin and its access to the brain after oral ingestion. Free Radic Biol Med. (2002)
  57. Fullerton DT, et al. Sugar, opioids and binge eating. Brain Res Bull. (1985)
  58. Gosnell BA1, Levine AS. Reward systems and food intake: role of opioids. Int J Obes (Lond). (2009)
  59. Macht M1, Mueller J. Immediate effects of chocolate on experimentally induced mood states. Appetite. (2007)
  60. Hou QL1, et al. SNAP-25 in hippocampal CA3 region is required for long-term memory formation. Biochem Biophys Res Commun. (2006)
  61. Wong RW1, et al. Overexpression of motor protein KIF17 enhances spatial and working memory in transgenic mice. Proc Natl Acad Sci U S A. (2002)
  62. Massolt ET, et al. Appetite suppression through smelling of dark chocolate correlates with changes in ghrelin in young women. Regul Pept. (2010)
  63. Francis ST, et al. The effect of flavanol-rich cocoa on the fMRI response to a cognitive task in healthy young people. J Cardiovasc Pharmacol. (2006)
  64. Mulert C1, et al. The relationship between reaction time, error rate and anterior cingulate cortex activity. Int J Psychophysiol. (2003)
  65. Chocolate consumption and risk of stroke: A prospective cohort of men and meta-analysis
  66. Wirtz PH1, et al. Dark chocolate intake buffers stress reactivity in humans. J Am Coll Cardiol. (2014)
  67. Jenny M1, et al. Cacao extracts suppress tryptophan degradation of mitogen-stimulated peripheral blood mononuclear cells. J Ethnopharmacol. (2009)
  68. Adams S1, et al. The kynurenine pathway in brain tumor pathogenesis. Cancer Res. (2012)
  69. Widner B1, et al. Neopterin production, tryptophan degradation, and mental depression--what is the link. Brain Behav Immun. (2002)
  70. Hoekstra R1, et al. Effect of light therapy on biopterin, neopterin and tryptophan in patients with seasonal affective disorder. Psychiatry Res. (2003)
  71. Maes M1, et al. Increased neopterin and interferon-gamma secretion and lower availability of L-tryptophan in major depression: further evidence for an immune response. Psychiatry Res. (1994)
  72. Gershon MD1, Tack J. The serotonin signaling system: from basic understanding to drug development for functional GI disorders. Gastroenterology. (2007)
  73. Pase MP, et al. Cocoa polyphenols enhance positive mood states but not cognitive performance: a randomized, placebo-controlled trial. J Psychopharmacol. (2013)
  74. Desideri G, et al. Benefits in cognitive function, blood pressure, and insulin resistance through cocoa flavanol consumption in elderly subjects with mild cognitive impairment: the Cocoa, Cognition, and Aging (CoCoA) study. Hypertension. (2012)
  75. Crews WD Jr1, Harrison DW, Wright JW. A double-blind, placebo-controlled, randomized trial of the effects of dark chocolate and cocoa on variables associated with neuropsychological functioning and cardiovascular health: clinical findings from a sample of healthy, cognitively intact older adults. Am J Clin Nutr. (2008)
  76. Gu Y, et al. Inhibition of key digestive enzymes by cocoa extracts and procyanidins. J Agric Food Chem. (2011)
  77. Nogueira L1, et al. (-)-Epicatechin enhances fatigue resistance and oxidative capacity in mouse muscle. J Physiol. (2011)
  78. Chocolate consumption and cardiometabolic disorders: systematic review and meta-analysis
  79. Mostofsky E, et al. Chocolate intake and incidence of heart failure: a population-based prospective study of middle-aged and elderly women. Circ Heart Fail. (2010)
  80. Buijsse B, et al. Cocoa intake, blood pressure, and cardiovascular mortality: the Zutphen Elderly Study. Arch Intern Med. (2006)
  81. Corti R, et al. Cocoa and cardiovascular health. Circulation. (2009)
  82. Shiina Y, et al. Acute effect of oral flavonoid-rich dark chocolate intake on coronary circulation, as compared with non-flavonoid white chocolate, by transthoracic Doppler echocardiography in healthy adults. Int J Cardiol. (2009)
  83. West SG1, et al. Effects of dark chocolate and cocoa consumption on endothelial function and arterial stiffness in overweight adults. Br J Nutr. (2014)
  84. Mogollon JA, et al. Blood pressure and endothelial function in healthy, pregnant women after acute and daily consumption of flavanol-rich chocolate: a pilot, randomized controlled trial. Nutr J. (2013)
  85. Pincomb GA, et al. Effects of caffeine on vascular resistance, cardiac output and myocardial contractility in young men. Am J Cardiol. (1985)
  86. Zhu QY1, et al. Inhibitory effects of cocoa flavanols and procyanidin oligomers on free radical-induced erythrocyte hemolysis. Exp Biol Med (Maywood). (2002)
  87. Zieman SJ1, Melenovsky V, Kass DA. Mechanisms, pathophysiology, and therapy of arterial stiffness. Arterioscler Thromb Vasc Biol. (2005)
  88. Theuwissen E1, Smit E, Vermeer C. The role of vitamin K in soft-tissue calcification. Adv Nutr. (2012)
  89. Tota-Maharaj R1, et al. Coronary artery calcium for the prediction of mortality in young adults <45 years old and elderly adults >75 years old. Eur Heart J. (2012)
  90. Pereira T1, et al. Central arterial hemodynamic effects of dark chocolate ingestion in young healthy people: a randomized and controlled trial. Cardiol Res Pract. (2014)
  91. Pearson DA, et al. Inhibition of in vitro low-density lipoprotein oxidation by oligomeric procyanidins present in chocolate and cocoas. Methods Enzymol. (2001)
  92. Kondo K, et al. Inhibition of LDL oxidation by cocoa. Lancet. (1996)
  93. Salah N, et al. Polyphenolic flavanols as scavengers of aqueous phase radicals and as chain-breaking antioxidants. Arch Biochem Biophys. (1995)
  94. Wan Y1, et al. Effects of cocoa powder and dark chocolate on LDL oxidative susceptibility and prostaglandin concentrations in humans. Am J Clin Nutr. (2001)
  95. Engler MB1, et al. Flavonoid-rich dark chocolate improves endothelial function and increases plasma epicatechin concentrations in healthy adults. J Am Coll Nutr. (2004)
  96. Sudarma V1, Sukmaniah S, Siregar P. Effect of dark chocolate on nitric oxide serum levels and blood pressure in prehypertension subjects. Acta Med Indones. (2011)
  97. Schnorr O, et al. Cocoa flavanols lower vascular arginase activity in human endothelial cells in vitro and in erythrocytes in vivo. Arch Biochem Biophys. (2008)
  98. Davison K1, et al. Effect of cocoa flavanols and exercise on cardiometabolic risk factors in overweight and obese subjects. Int J Obes (Lond). (2008)
  99. Ottaviani JI, et al. The stereochemical configuration of flavanols influences the level and metabolism of flavanols in humans and their biological activity in vivo. Free Radic Biol Med. (2011)
  100. Schroeter H, et al. (-)-Epicatechin mediates beneficial effects of flavanol-rich cocoa on vascular function in humans. Proc Natl Acad Sci U S A. (2006)
  101. Hermann F, et al. Dark chocolate improves endothelial and platelet function. Heart. (2006)
  102. Faridi Z, et al. Acute dark chocolate and cocoa ingestion and endothelial function: a randomized controlled crossover trial. Am J Clin Nutr. (2008)
  103. d'El-Rei J1, et al. Characterisation of hypertensive patients with improved endothelial function after dark chocolate consumption. Int J Hypertens. (2013)
  104. Effects of Dark Chocolate and Cocoa Products on Endothelial Function: A Meta-Analysis
  105. Farouque HM, et al. Acute and chronic effects of flavanol-rich cocoa on vascular function in subjects with coronary artery disease: a randomized double-blind placebo-controlled study. Clin Sci (Lond). (2006)
  106. Persson IA, et al. Effects of cocoa extract and dark chocolate on angiotensin-converting enzyme and nitric oxide in human endothelial cells and healthy volunteers--a nutrigenomics perspective. J Cardiovasc Pharmacol. (2011)
  107. Ried K, et al. Does chocolate reduce blood pressure? A meta-analysis. BMC Med. (2010)
  108. Vlachopoulos C, Alexopoulos N, Stefanadis C. Effect of dark chocolate on arterial function in healthy individuals: cocoa instead of ambrosia. Curr Hypertens Rep. (2006)
  109. Fraga CG1, et al. Regular consumption of a flavanol-rich chocolate can improve oxidant stress in young soccer players. Clin Dev Immunol. (2005)
  110. Ried K, et al. Effect of cocoa on blood pressure. Cochrane Database Syst Rev. (2012)
  111. Bijak M1, et al. Protective effects of (-)-epicatechin against nitrative modifications of fibrinogen. Thromb Res. (2012)
  112. Wippel R1, et al. Interference of the polyphenol epicatechin with the biological chemistry of nitric oxide- and peroxynitrite-mediated reactions. Biochem Pharmacol. (2004)
  113. Nowak P1, Wachowicz B. Peroxynitrite-mediated modification of fibrinogen affects platelet aggregation and adhesion. Platelets. (2002)
  114. Wirtz PH1, et al. Independent association between lower level of social support and higher coagulation activity before and after acute psychosocial stress. Psychosom Med. (2009)
  115. Wirtz PH1, et al. Coagulation activity before and after acute psychosocial stress increases with age. Psychosom Med. (2008)
  116. von Känel R, et al. Effects of dark chocolate consumption on the prothrombotic response to acute psychosocial stress in healthy men. Thromb Haemost. (2014)
  117. Hamed MS1, et al. Dark chocolate effect on platelet activity, C-reactive protein and lipid profile: a pilot study. South Med J. (2008)
  118. Rein D1, et al. Cocoa inhibits platelet activation and function. Am J Clin Nutr. (2000)
  119. Pearson DA1, et al. The effects of flavanol-rich cocoa and aspirin on ex vivo platelet function. Thromb Res. (2002)
  120. Ostertag LM1, et al. Flavan-3-ol-enriched dark chocolate and white chocolate improve acute measures of platelet function in a gender-specific way--a randomized-controlled human intervention trial. Mol Nutr Food Res. (2013)
  121. Tokede OA, Gaziano JM, Djoussé L. Effects of cocoa products/dark chocolate on serum lipids: a meta-analysis. Eur J Clin Nutr. (2011)
  122. Grassi D1, et al. Short-term administration of dark chocolate is followed by a significant increase in insulin sensitivity and a decrease in blood pressure in healthy persons. Am J Clin Nutr. (2005)
  123. Almoosawi S1, et al. The effect of polyphenol-rich dark chocolate on fasting capillary whole blood glucose, total cholesterol, blood pressure and glucocorticoids in healthy overweight and obese subjects. Br J Nutr. (2010)
  124. Grassi D1, et al. Protective effects of flavanol-rich dark chocolate on endothelial function and wave reflection during acute hyperglycemia. Hypertension. (2012)
  125. Kim JA1, et al. Reciprocal relationships between insulin resistance and endothelial dysfunction: molecular and pathophysiological mechanisms. Circulation. (2006)
  126. Konopatskaya O1, et al. Insulin and lysophosphatidylcholine synergistically stimulate NO-dependent cGMP production in human endothelial cells. Diabet Med. (2003)
  127. Di Renzo L1, et al. Effects of dark chocolate in a population of normal weight obese women: a pilot study. Eur Rev Med Pharmacol Sci. (2013)
  128. Arend WP1, et al. Interleukin-1 receptor antagonist: role in biology. Annu Rev Immunol. (1998)
  129. Cartier A1, et al. Increased plasma interleukin-1 receptor antagonist levels in men with visceral obesity. Ann Med. (2009)
  130. Meier CA1, et al. IL-1 receptor antagonist serum levels are increased in human obesity: a possible link to the resistance to leptin. J Clin Endocrinol Metab. (2002)
  131. Nogueira Lde P1, et al. Consumption of high-polyphenol dark chocolate improves endothelial function in individuals with stage 1 hypertension and excess body weight. Int J Hypertens. (2012)
  132. Gutierrez-Salmean G1, et al. Effects of (-)-epicatechin on molecular modulators of skeletal muscle growth and differentiation. J Nutr Biochem. (2014)
  133. Watanabe N, et al. Flavan-3-ols fraction from cocoa powder promotes mitochondrial biogenesis in skeletal muscle in mice. Lipids Health Dis. (2014)
  134. Taub PR1, et al. Alterations in skeletal muscle indicators of mitochondrial structure and biogenesis in patients with type 2 diabetes and heart failure: effects of epicatechin rich cocoa. Clin Transl Sci. (2012)
  135. Hüttemann M1, et al. (-)-Epicatechin is associated with increased angiogenic and mitochondrial signalling in the hindlimb of rats selectively bred for innate low running capacity. Clin Sci (Lond). (2013)
  136. Davison G1, et al. The effect of acute pre-exercise dark chocolate consumption on plasma antioxidant status, oxidative stress and immunoendocrine responses to prolonged exercise. Eur J Nutr. (2012)
  137. Allgrove J1, et al. Regular dark chocolate consumption's reduction of oxidative stress and increase of free-fatty-acid mobilization in response to prolonged cycling. Int J Sport Nutr Exerc Metab. (2011)
  138. Okano G1, Sato Y, Murata Y. Effect of elevated blood FFA levels on endurance performance after a single fat meal ingestion. Med Sci Sports Exerc. (1998)
  139. Leick L1, et al. PGC-1alpha is required for training-induced prevention of age-associated decline in mitochondrial enzymes in mouse skeletal muscle. Exp Gerontol. (2010)
  140. Koch LG1, Britton SL. Artificial selection for intrinsic aerobic endurance running capacity in rats. Physiol Genomics. (2001)
  141. Naples SP1, et al. Skeletal muscle mitochondrial and metabolic responses to a high-fat diet in female rats bred for high and low aerobic capacity. Appl Physiol Nutr Metab. (2010)
  142. Kivelä R1, et al. Gene expression centroids that link with low intrinsic aerobic exercise capacity and complex disease risk. FASEB J. (2010)
  143. Rivas DA1, et al. Low intrinsic running capacity is associated with reduced skeletal muscle substrate oxidation and lower mitochondrial content in white skeletal muscle. Am J Physiol Regul Integr Comp Physiol. (2011)
  144. Lessard SJ1, et al. Exercise training reverses impaired skeletal muscle metabolism induced by artificial selection for low aerobic capacity. Am J Physiol Regul Integr Comp Physiol. (2011)
  145. Hepple RT1, Vogell JE. Anatomic capillarization is maintained in relative excess of fiber oxidative capacity in some skeletal muscles of late middle-aged rats. J Appl Physiol (1985). (2004)
  146. Hüttemann M1, Lee I, Malek MH. (-)-Epicatechin maintains endurance training adaptation in mice after 14 days of detraining. FASEB J. (2012)
  147. Mao TK1, et al. Effect of cocoa flavanols and their related oligomers on the secretion of interleukin-5 in peripheral blood mononuclear cells. J Med Food. (2002)
  148. Ramiro E1, et al. Flavonoids from Theobroma cacao down-regulate inflammatory mediators. J Agric Food Chem. (2005)
  149. Al-Hanbali M1, et al. Epicatechin suppresses IL-6, IL-8 and enhances IL-10 production with NF-kappaB nuclear translocation in whole blood stimulated system. Neuro Endocrinol Lett. (2009)
  150. Wisman KN1, et al. Accurate assessment of the bioactivities of redox-active polyphenolics in cell culture. J Agric Food Chem. (2008)
  151. Kenny TP1, et al. Immune effects of cocoa procyanidin oligomers on peripheral blood mononuclear cells. Exp Biol Med (Maywood). (2007)
  152. Becker K1, et al. Immunomodulatory properties of cacao extracts - potential consequences for medical applications. Front Pharmacol. (2013)
  153. Asehnoune K1, et al. Involvement of reactive oxygen species in Toll-like receptor 4-dependent activation of NF-kappa B. J Immunol. (2004)
  154. Andert SE1, et al. Neopterin release from human endothelial cells is triggered by interferon-gamma. Clin Exp Immunol. (1992)
  155. Hofmann B1, et al. Different lymphoid cell populations produce varied levels of neopterin, beta 2-microglobulin and soluble IL-2 receptor when stimulated with IL-2, interferon-gamma or tumour necrosis factor-alpha. Clin Exp Immunol. (1992)
  156. Fuchs D1, et al. Decreased serum tryptophan in patients with HIV-1 infection correlates with increased serum neopterin and with neurologic/psychiatric symptoms. J Acquir Immune Defic Syndr. (1990)
  157. Pfefferkorn ER. Interferon gamma and the growth of Toxoplasma gondii in fibroblasts. Ann Inst Pasteur Microbiol. (1986)
  158. Nathan CF. Peroxide and pteridine: a hypothesis on the regulation of macrophage antimicrobial activity by interferon gamma. Interferon. (1986)
  159. Hronek M1, et al. The association between specific nutritional antioxidants and manifestation of colorectal cancer. Nutrition. (2000)
  160. Nath S, et al. Catechins protect neurons against mitochondrial toxins and HIV proteins via activation of the BDNF pathway. J Neurovirol. (2012)
  161. Ruijters EJ1, et al. The cocoa flavanol (-)-epicatechin protects the cortisol response. Pharmacol Res. (2014)
  162. Tzounis X, et al. Prebiotic evaluation of cocoa-derived flavanols in healthy humans by using a randomized, controlled, double-blind, crossover intervention study. Am J Clin Nutr. (2011)
  163. Tzounis X, et al. Flavanol monomer-induced changes to the human faecal microflora. Br J Nutr. (2008)
  164. Lee HC, et al. Effect of tea phenolics and their aromatic fecal bacterial metabolites on intestinal microbiota. Res Microbiol. (2006)
  165. McCormick PA1, et al. The effect of non-protein liquid meals on the hepatic venous pressure gradient in patients with cirrhosis. J Hepatol. (1990)
  166. O'Brien S1, et al. Postprandial changes in portal haemodynamics in patients with cirrhosis. Gut. (1992)
  167. Bellis L1, et al. Low doses of isosorbide mononitrate attenuate the postprandial increase in portal pressure in patients with cirrhosis. Hepatology. (2003)
  168. Hernández-Guerra M1, et al. Ascorbic acid improves the intrahepatic endothelial dysfunction of patients with cirrhosis and portal hypertension. Hepatology. (2006)
  169. De Gottardi A1, et al. Postprandial effects of dark chocolate on portal hypertension in patients with cirrhosis: results of a phase 2, double-blind, randomized controlled trial. Am J Clin Nutr. (2012)
  170. Quine SD1, Raghu PS. Effects of (-)-epicatechin, a flavonoid on lipid peroxidation and antioxidants in streptozotocin-induced diabetic liver, kidney and heart. Pharmacol Rep. (2005)
  171. Pruijm M, et al. Effect of dark chocolate on renal tissue oxygenation as measured by BOLD-MRI in healthy volunteers. Clin Nephrol. (2013)
  172. Terai N1, et al. The short-term effect of flavonoid-rich dark chocolate on retinal vessel diameter in glaucoma patients and age-matched controls. Acta Ophthalmol. (2014)
  173. Moreno-Ulloa A1, et al. Recovery of Indicators of Mitochondrial Biogenesis, Oxidative Stress, and Aging With (-)-Epicatechin in Senile Mice. J Gerontol A Biol Sci Med Sci. (2014)
  174. Caperton C1, et al. Double-blind, Placebo-controlled Study Assessing the Effect of Chocolate Consumption in Subjects with a History of Acne Vulgaris. J Clin Aesthet Dermatol. (2014)
  175. Anderson PC. Foods as the cause of acne. Am Fam Physician. (1971)
  176. Block SG, et al. Exacerbation of facial acne vulgaris after consuming pure chocolate. J Am Acad Dermatol. (2011)
  177. Bedard K1, Krause KH. The NOX family of ROS-generating NADPH oxidases: physiology and pathophysiology. Physiol Rev. (2007)
  178. Loffredo L1, et al. Imbalance between nitric oxide generation and oxidative stress in patients with peripheral arterial disease: effect of an antioxidant treatment. J Vasc Surg. (2006)
  179. Hammer A1, et al. Dark chocolate and vascular function in patients with peripheral artery disease: A randomized, controlled cross-over trial. Clin Hemorheol Microcirc. (2014)
  180. Rabbitt P1, et al. Losses in gross brain volume and cerebral blood flow account for age-related differences in speed but not in fluid intelligence. Neuropsychology. (2006)
  181. Spilt A1, et al. Late-onset dementia: structural brain damage and total cerebral blood flow. Radiology. (2005)
  182. Commenges D1, et al. Intake of flavonoids and risk of dementia. Eur J Epidemiol. (2000)
  183. Galli RL1, et al. Fruit polyphenolics and brain aging: nutritional interventions targeting age-related neuronal and behavioral deficits. Ann N Y Acad Sci. (2002)
  184. Fisher ND1, Sorond FA, Hollenberg NK. Cocoa flavanols and brain perfusion. J Cardiovasc Pharmacol. (2006)
  185. Nagahama Y1, et al. Cerebral correlates of the progression rate of the cognitive decline in probable Alzheimer's disease. Eur Neurol. (2003)
  186. Johnson KA1, et al. Preclinical prediction of Alzheimer's disease using SPECT. Neurology. (1998)
  187. Chan EK1, et al. Dark chocolate for children's blood pressure: randomised trial. Arch Dis Child. (2012)
  188. Ried K1, Frank OR, Stocks NP. Dark chocolate or tomato extract for prehypertension: a randomised controlled trial. BMC Complement Altern Med. (2009)

(Common misspellings for Cocoa Extract include chocmine, choamine, chocolamine)

(Common phrases used by users for this page include myokines supplements, cocoa powder extract, cocoa extract caffeine, cocao benefits extract, chocamine composition, Brazilian Cocoa Extract)

(Users who contributed to this page include , Primalkid, )