Studies related to Platelet Aggregation and Cocoa Extract

Dark Chocolate Effect On Platelet Activity, C-reactive Protein And Lipid Profile: A Pilot Study

Effect Decrease
Trial Design Cohort
Trial Length 1-7 Days
Number of Subjects 28
Gender Both Genders
Age Range 18-29
Notes for this study:
700mg of cocoa flavonoids daily for one week in otherwise healthy subjects appeared to have mild beneficial effects on serum lipoproteins (LDL and HDL) but primarily reduced the aggregatory potential of platelets when they were stimulated outside the body.

High sensitivity C-reactive protein decreased, suggesting an antiinflammatory property; this effect was only noted in women. No placebo control was used in this study.

Safety And Efficacy Of Cocoa Flavanol Intake In Healthy Adults: A Randomized, Controlled, Double-masked Trial

Effect None
Trial Design Randomized trial
Trial Length 1-6 months
Number of Subjects 108
Gender Both Genders
Age Range 30-44, 45-64
Notes for this study:
Daily intake of up to 2000mg/day cocoa flavanols failed to affect blood pressure, platelet function, or metabolic variables relative to placebo controls in healthy individuals at low risk for cardiovascular disease. While 2000mg/day failed to affect the above clinical outcomes, it was well tolerated.
Funding issues for this study:
This study was funded by Mars, Inc, which manufactures the cocoa extract.

The Effects Of Flavanol-rich Cocoa And Aspirin On Ex Vivo Platelet Function

Effect Decrease
Trial Design Cohort
Trial Length 24 hours
Number of Subjects 16
Gender Both Genders
Age Range 18-29
Notes for this study:
Acute ingestion of cocoa polyphenolics (total epicatechin and procyanidins of 900mg) taken as a single dose appeared to have anti-clotting properties when platelets were tested six hours later; the potency was lesser than aspirin (81mg) but the two seemed additive.

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

Effect Decrease
Trial Design Cohort
Trial Length 24 hours
Number of Subjects 42
Gender Both Genders
Age Range 18-29, 30-44
Notes for this study:
Beverages enriched by the flavan-3-ol fraction of cocoa have antiplatelet activity when tested two and six hours after ingestion in both biological sexes, although there appeared to be some differences between the two not explained by pharmacokinetics.

Men appeared to experienced less aggregation from ADP, while women experienced benefits via the thrombin receptor; both groups saw benefits on collagen-induced bleeding time. There may have been some compounds in the control (white chocolate) which were also bioactive.

Dark Chocolate Inhibits Platelet Isoprostanes Via NOX2 Down-regulation In Smokers

Effect Decrease
Trial Design Double blind
Trial Length 24 hours
Number of Subjects 40
Gender Both Genders
Age Range 18-29, 30-44
Body Types Average
Notes for this study:
In smokers, but not healthy nonsmoking controls, 40 grams of 85% dark chocolate eaten two hours before measurement was able to reduce platelet function (thought to reflect reduced potential to aggregate) secondary to suppressing NOX2 activity. The suppressive effects on NOX2 were due to an antioxidative effect of (-)-epicatechin in serum.

Smokers have higher baseline NOX2 activity and platelet function, milk chocolate (no catechins) was used as the control.