The latest from Examine

Do plausible mechanisms for vitamin C equal good outcomes for diabetes?

Norman Haworth determined the chemical structure of vitamin C in 1933. Since then, vitamin C has been the subject of many studies, for a wide range of potential benefits. Can it help with diabetes? A recent study combined 28 randomized controlled trials to answer this question.

Read our analysis of this study. ⁠

Did you know?

Many of our modern drugs are based on chemicals found in nature. For example, aspirin (acetylsalicylic acid) is only a slight modification of salicylic acid, which is found in willow bark.⁠

If you were without internet access for one month, what would you be doing?

Join the conversation.

Can food have negative calories?

Negative calorie foods are foods purported to have fewer calories than the body expends to digest them. However, while some foods do contain very few calories, evidence supporting the existence of negative calorie foods is lacking.

Click through to learn more.⁠⁠⁠⁠⁠

Top 5 Study Summaries for July 2022

Each month, we summarize 150+ recent studies for our Members. Read five of this month’s most favorited Study Summaries for free.⁠⁠⁠⁠⁠

Eggs or cereal — which breakfast makes you eat less for lunch?

What you eat during a meal has been shown to affect how much you eat during the next meal.⁠⁠⁠⁠⁠

This study measured the caloric intake at lunch of people with overweight or obesity after they were given either cereal or two eggs for breakfast. ⁠⁠⁠⁠⁠

Click through to read the full Study Summary for free. ⁠⁠⁠⁠⁠

Did you know the difference between chronic pain and intractable pain?

Chronic pain is pain that continues a month or more beyond the usual recovery period for an injury or illness, or that goes on for months or years due to a chronic condition. Constant pain that cannot be sufficiently reduced is often categorized as intractable pain, and can have widespread physiological effects. ⁠⁠⁠⁠⁠

Click for related information on pain.

Do you listen to music when you work? If so, what type?⁠⁠

Join the conversation.

Episode VI: Return of the Researcher

Tweaks Google made to its search algorithm in 2018 and 2019 reduced our traffic by ≈90%. This should have been a death sentence. Yet here we are, 3 years later, with a much bigger team and a brand-new website launching in August. 🚀 ⁠⁠⁠⁠⁠

Read our story.

Children's health tip:

Play is a powerful emotional regulator in kids! Elementary-aged children experience less pain and fear during some minor medical procedures when they’re distracted by a simple kaleidoscope.⁠ ⁠⁠⁠⁠⁠

Click through for more details in the full Study Summary.

Did you know?

Like women, men experience a decline in sex hormones as they age — a phenomenon known (in some circles) as “andropause”. Unlike menopause, which can happen very quickly, men’s decline in sex hormones is typically gradual.⁠ ⁠⁠⁠⁠⁠

What supplements affect libido and sexual health? We've compiled a list with evidence-based information.

When and why did you start caring more about health and nutrition?⁠⁠

Join the conversation.

Sleep tip

When you are cold, your peripheral blood vessels constrict to spare body heat for your vital organs. Conversely, if you take a warm bath, they relax, so that when you exit the bath, you cool off quickly, which may help you fall asleep faster and sleep better.⁠ ⁠⁠⁠⁠

Click for more tips for better sleep.

Lower fat intake, lower testosterone levels??

“Low-fat diets kill your testosterone, bro!” ⁠⁠⁠

The claim that eating less fat means producing less T was investigated in a 2021 meta-analysis of 6 trials (206 healthy men, total). Click through to read our analysis of this study. ⁠⁠⁠

Spoiler: The trials didn’t all reach the same conclusion. Genetics and the type of dietary fat seem to affect the results. Future research will need to explore these two factors; we’ll keep our eyes out and keep you updated!

What's the best-tasting meal you could make using just a microwave?

Join the conversation.

Can weighted blankets help with insomnia?

Insomnia (issues falling or staying asleep) can result in fatigue, anxiety, and depression. About 40% of insomniacs do not respond to the two standard treatments — pharmaceuticals and cognitive behavioral therapy. ⁠ ⁠⁠

Weight blankets apply deep pressure stimulation (DPS) to the whole body; there is mixed evidence that they improve sleep and anxiety. DPS also increases the production of oxytocin, a hormone critical to relaxation and sleep. ⁠⁠

Can weighted blankets alleviate insomnia in people with psychiatric conditions? Click through for the full study summary.

Gut health tip:

The effects of probiotics are strain- and disease-specific, so unless you’re using the proper strain for your situation — such as 𝘚𝘢𝘤𝘤𝘩𝘢𝘳𝘰𝘮𝘺𝘤𝘦𝘴 𝘣𝘰𝘶𝘭𝘢𝘳𝘥𝘪𝘪 CNCM I-745 to prevent antibiotic-associated diarrhea — you could be wasting your money.⁠

Click for more information on gut health supplements.

Examine 2.0 is launching in late July! 🚀

For the past couple of years, we’ve been hard at work assembling a website that’s faster and sturdier (the underlying code is all new), with a much clearer interface and better-organized, more useful information. And a much improved search function!

Click to learn more about the dramatically improved Examine and everything that led to it.

Does exercise make you hungrier?

Could it even make you eat more calories than you burned? A systematic review of 48 studies explored this question, and we analyzed it for you. Click through to read the full analysis. As usual, though, remember that your mileage may vary.⁠⁠

The review we analyzed looked at average responses in a variety of studies, not at you specifically. So exercise can certainly have a neutral, positive, or negative impact on your personal energy balance.

Remember that exercise’s impact on your personal energy balance can also vary, changing over time or in different life contexts.

So basically, don’t let this evidence negate your personal experience, and don’t use it to tell someone that their personal experience is invalid!

Broccoli cooking tip

Sulforaphane is a sulfur-rich compound with potential health benefits. Broccoli microwaved to 60°C (140°F) has about 80% more sulforaphane than broccoli cooked at the same temperature in a lidded, water-filled pot.⁠ ⁠⁠

Click through to learn more about sulforaphane.

What is a p-value?

Whether the evidence for a study result is strong depends notably on this result’s 𝘱-value, so understanding 𝘱-values is important! Unfortunately, they’re not intuitive. Fortunately, our primer is both simple enough for laymen and correct enough for the stickler biostatisticians among you. 🧐📈⁠⁠

Impossible? Well, click through to find out.

Did you know?

Some pharmaceuticals marketed as sleep aids are better at producing unconsciousness than actual sleep, as measured by electroencephalography (EEG). For example, compared to melatonin, zolpidem has been shown to reduce slow-wave sleep.⁠ ⁠

Click through for more information on melatonin.

What is your post-workout recovery routine?⁠

Join the conversation.

Got acid reflux? Take a deep breath!

At the end of two trials (Qiu et al. Ann Palliat Med. 2020 Mar), lasting 6 and 9 months, breathing exercises had reduced the need for acid-suppressing medication.⁠

Click through for supplements and interventions related to gut health.

Is Kefir good for you?

🥛🦠 Kefir is milk fermented with kefir grains, a symbiotic culture of yeast and bacteria. It is similar to (and tastes like) liquid yogurt.

You might have seen health gurus call kefir a “supercharged probiotic” and “microbiome balancer” — but the picture drawn by the evidence is more nuanced.

Kefir appears to be good for some people, bad for others. Our new page on kefir walks you through the evidence for various case scenarios.⁠

Did you know?

Depression is probably mediated more by glutamate and GABA than by serotonin, but serotonergic neurons can affect glutamate and GABA levels indirectly, which may be why selective serotonin reuptake inhibitors (SSRIs) are a common treatment for depression.⁠ ⁠ ⁠

Click for more information about depression.⁠

What are your top 3 sources of fiber?⁠

Join the conversation.

Citrulline malate may help you pump out a few extra reps

The market is flooded with performance-enhancing supplements, few of which actually work. Citrulline malate has emerged as a legitimate contender in recent years, but the evidence is still far from creatine-level.

We covered reasons for optimism and reasons for caution in our summary of a recent meta-analysis of eight randomized trials. ⁠

Reconnect with nature to reduce stress and blood pressure

Time spent in nature relaxes you both subjectively (you feel calmer) and objectively (your cortisol and blood pressure decrease, notably).⁠ ⁠

Click through to check out a Study Summary on "Forest bathing". ⁠ ⁠

Podcast interview with RDs vs. BS: Why your mouse study doesn't impress us.

Why's there so much conflicting information in nutrition, and how should you make sense of it?

Nick Milazzo, the Editor of Study Summaries, shares his insights on how to navigate the murky waters of nutrition research on the podcast, RDs vs. BS. They discuss why nutrition research is difficult to conduct, why findings are usually inconclusive, and how data can be used as a weapon to sell exaggerated claims.

Listen to the full episode on RDs vs. BS.

Did you know?

Grapefruits contain compounds that inhibit liver enzymes required to metabolize many drugs. As a result, grapefruits can modulate the potency of caffeine and many pharmaceuticals, including warfarin and birth-control pills.

Click for more evidence-based information on grapefruit.

If they had the same taste and nutritional value, would you choose regular meat, lab-grown meat, or meat analogues? ⁠

Join the conversation.

Does "peer-reviewed" mean "true"?

Peer review isn't foolproof, click through to find out why.

Top 5 Study Summaries

Each month, we summarize 150+ recent studies for our Examine Members. Click through to read five of this month's most favorited Study Summaries.

This month’s selection includes two Editor’s Picks (more detailed Study Summaries, with helpful graphics).⁠

Examine in the press: "Does turmeric’s reputation translate into real health benefits?" by the Guardian

We humbly thank The Guardian for reaching out to us for our unbiased insights on curcumin. This yellow-orange chemical found in turmeric (a tall plant in the ginger family, native to Asia) is one of the most searched-for supplements on Examine, possibly due to its purported anti-inflammatory properties.

Read the full article on the Guardian, featuring quotes from our co-founder, Kamal Patel and resident researcher, Wyatt Brown.

For more on curcumin, click here.⁠

Preview Examine v2 and get on the prelist for extra gifts!

Arriving in July with some gifts to you. ⁠
It's hot, it's purple, it's Examine v2!

Get a glimpse of what's to come and sign up for the prelist for early access, big savings and a chance to win a Lifetime Membership!

Melatonin can benefit the heart?

Melatonin is a hormone best known for its role in regulating sleep-wake cycles. In addition to inducing sleepiness, melatonin administration may reduce blood pressure, protect against heart attacks, and reduce cardiac oxidative stress.⁠ ⁠

What does the evidence say about melatonin and your health? Click through for our full analysis. All for free. 😎 ⁠

What's your favorite nut (and nut butter) and why? ⁠

Join the conversation.

Examine in the press: "Can protein powders help aging muscles?" by the New York Times

Recently, the New York Times looked at how protein powder can help aging muscles and we are honored to have had our very own resident researcher, Dr. Bill Willis, a protein synthesis expert, give his insights on how to minimize sarcopenia (age-related muscle loss).⁠

Read the full article on The New York Times.

Click here for more on sarcopenia.

Click here for our protein intake guide for older adults.

Sugar-free gum and your health

Sugar-free gum, particularly gum containing xylitol, may reduce the risk of cavities. That being said, you’ll probably have to consume a lot for it to have an effect.⁠

Does chewing gum offer any health benefits?⁠ Click through to find out.

Did you know that not all body fat is the same?

Not all body fat is equal. Distributed as it is around the organs, visceral fat is more closely correlated with inflammation and metabolic disease than is subcutaneous fat (the fat just below the skin).⁠

Click for more about inflammation. ⁠

Caffeine and chocolate

A 2014 study found 42 to 278 mg of caffeine per 100 grams of chocolate, depending on brand and cacao content (with more cacao usually translating as more caffeine). This helps explain why chocolate is a little addictive!⁠

Click through for more on caffeine.

Did you know the liver regulates iron levels?

The liver stores a lot of iron, which it releases into circulation when levels are low. Thus, the liver plays a major role in regulating iron levels, and liver diseases can lead to iron-deficiency anemia.⁠⁠

Learn more about iron and other possible causes of deficiency.

Do you count calories? Why or why not?⁠

Join the conversation.

Healthy Aging Supplement Guide

Since we’re not getting any younger ourselves, we parsed the literature to determine which supplements are most likely to help us maintain our quality of life as we age. And we want to share our findings with you. Click through to get our Healthy Aging Supplement guide for FREE, and if you have friends who’d benefit from this guide too (hint: everyone can 😉), share it with them!

Did you know this about testosterone?

Together, your free testosterone and your loosely bound testosterone compose your bioavailable testosterone, which has a greater impact on your health than your total testosterone.

Click through for more information on testosterone.

How effective is vitamin C actually in fighting off a common cold?

Can it help to improve blood sugar control? How does it affect exercise recovery?⁠

Our team here at Examine parses scientific research day in and day out. We've noted what the evidence says about these questions with more in-depth information over on our vitamin C supplement page.

Can a week of unrestricted sleep make up for long-term sleep loss?

We're all familiar with long days and nights, whether they're due to work, insomnia, or an erratic schedule. Sleep is critical for a lot of health outcomes, such as metabolic health, immune health, and cognition, as shown in this picture. So it makes sense to wonder: is "catching up on sleep" actually a thing? A recent study investigated how sleep recovery affected cognitive performance after 10 days of sleep restriction.⁠

Do you need a detox?

While there are some things you can do to help your body’s built-in detoxification system function optimally, there is a lack of strong scientific evidence to support the safety and efficacy of most commercial detoxification programs. Click through to learn more.

Creatine is one of the most well-studied supplements

Aside from enhancing power output during exercise, what other effects does it have on the body?

Click through to check out our comprehensive supplement page on creatine. ⁠

Do you warm up before lifting weights?
Do you stretch?⁠

Join the conversation.

How much protein do you need?

In our Optimal Protein Intake Guide, you’ll find the optimal protein-intake range for pregnant women, active adults focusing on muscle gain, sedentary adults trying to lose some fat, and so on and so forth. You’ll also find information on protein intake per meal, protein intake after exercise, vegan proteins, and more! All of it fully referenced, and yes, completely free.⁠

Goji berries for blood glucose and lipid metabolism

What does the research say about goji berries and metabolic health?

We analyzed a meta-analysis of 6 randomized controlled trials.

Top 5 Study Summaries - April 2022

Each month, we summarize 150+ recent studies for our Examine.

Click through to see this month's favorite Study Summaries.

This month’s selection includes an Editor’s Pick (a more detailed Study Summary, with helpful graphics).⁠

How much caffeine is in different chocolate brands?

If you’ve ever noticed that you feel more alert after eating your favorite chocolate bar, that’s because cocoa naturally contains caffeine — the world’s most widely used psychoactive drug. Like this chart from Müller et al.’s study shows, chocolate bars that contain more cocoa tend to also contain more caffeine, even across different brands.

⁠ Based on this chart, you’re consuming about 0.5–2.5 mg of caffeine per gram of chocolate. For comparison, your morning cup of coffee can have about 50–250 mg of caffeine, depending on how it’s prepared (PMID: 34071879).

Learn more about caffeine’s effects on exercise performance, cortisol, cognition, and more.

Did you know some foods contain trace amounts of nicotine?

Some common foods contain trace amounts of nicotine: ≤0.00159 mg/kg for chocolate 🍫 and ≤0.0042 mg/kg (i.e., ≤0.0042 mg/L) for brewed tea 🍵, for instance, compared to ≤24,000 mg/kg for tobacco (of which about 1/10 get absorbed when smoking a cigarette 🚬).

Click through for more information on nicotine.⁠

Don’t fall into the “is this food healthy or unhealthy?” trap

The term "healthy" is overused when it comes to foods and diets. Individual reactions vary widely, and there are still many open questions in need of research.⁠

Nootropic: Alpha-GPC

Alpha-GPC is one of the more common nootropic supplements used for cognitive enhancements. One study has even shown it to improve power output in athletes.

Click through to learn more about its effects and how to safely take it.

Drug-free treatments for hypertension?

🩸📉 If you have high blood pressure, like almost 30% of Americans, is there something you can do — aside from medicating?⁠⁠

A recent study compared various lifestyle interventions.

‘Chemical’ is not a bad word.

In fact, everything you can see, breathe, smell, taste, or touch, including the human body, is made up entirely of chemicals! This means trying to “avoid chemicals” is impossible!⁠

⁠ What you probably DO want to avoid, though, is exposure to harmful chemicals in quantities that are likely to negatively affect your health. These chemicals (which include metals/metalloids, antimicrobials, microplastics, mycotoxins, and pesticides) can contaminate food and water, with the sources of contamination including the environment, agricultural practices, industrial waste, food packaging, and even cooking practices! ⁠

⁠ For an in-depth review on the topic, click through to check out Thompson and Darwish's 2019 study in the 𝐽𝑜𝑢𝑟𝑛𝑎𝑙 𝑜𝑓 𝑇𝑜𝑥𝑖𝑐𝑜𝑙𝑜𝑔𝑦.

Stress and its influence on aging

Stress resilience is key to aging well. A person who is 100 years old is 100 years old in chronological age, but their biological age — how old their cells and tissues are — can be different, and is more indicative of their susceptibility to chronic disease and other health burdens. ⁠ ⁠

Chronic stress can accelerate biological aging through epigenetic mechanisms. We recently summarized an interesting study that dives into those mechanisms and how they relate to health outcomes like insulin resistance and adrenal sensitivity.

Of mice, men, and gainz

“Mouse research doesn’t apply very well to humans.”⁠


⁠𝙐𝙣𝙩𝙞𝙡 𝙣𝙤𝙬.⁠

⁠Read on to discover the most exciting discovery of the century.

A weight-neutral approach to obesity

In this narrative review, the authors proposed a weight-neutral strategy for obesity treatment, focused on increasing physical activity and cardiorespiratory fitness. Some of the authors’ conclusions should be interpreted with caution, as there were several instances in which they cited research that didn’t support their statements. Nevertheless, the general sentiment that weight-neutral interventions can effectively improve health and reduce risk for chronic disease is well-supported by the current body of literature.

The effects of full fasting vs. modified fasting on cognitive performance

🍽️ 🧠 Fasting has been said to harm cognition and work capacity. A recent trial put this theory to the test. Read our analysis.

IIFYM (If It Fits Your Macros)

IIFYM (If It Fits Your Macros) is one of the most popular types of “flexible diets”. It lets you eat whatever foods you want, within some protein/fat/carbs guidelines. A recent randomized trial tested this approach against a more rigid diet with a structured meal plan, investigating the effects of each on body composition and resting metabolic rate.⁠

Vitamin D and the risk of falls in older adults

☀️💊 Are older people who supplement with vitamin D more or less likely to fall?⁠ Studies published mere months apart report seemingly conflicting results. In some trials, vitamin D decreased the risk of falls. In others, once-a-month megadoses 𝘪𝘯𝘤𝘳𝘦𝘢𝘴𝘦𝘥 the risk of falls. In others still, vitamin D had no effect.⁠ Even meta-analyses of these trials don’t always shed a light, as they often overlook details that could explain those discrepancies.⁠

Pesticide exposure can increase with a Mediterranean diet but decrease with organic food

Earlier this year, 𝑇ℎ𝑒 𝐴𝑚𝑒𝑟𝑖𝑐𝑎𝑛 𝐽𝑜𝑢𝑟𝑛𝑎𝑙 𝑜𝑓 𝐶𝑙𝑖𝑛𝑖𝑐𝑎𝑙 𝑁𝑢𝑡𝑟𝑖𝑡𝑖𝑜𝑛 published a study on pesticides and organic foods. Switching from a Western diet to a Mediterranean diet increased urinary pesticide residues, except when organic foods were used.

The Top 5 Study Summaries

Every month, we summarize 150+ new studies for our Examine Members.

Check out our Members’ favorite summaries for March 2022.

This month’s favorites include two Editor’s Picks, which delve deeper into the studies and include helpful graphics.⁠

Food addiction: is it real, and does that matter?

☀️🍰 😍 Food addiction: Is it real, and does it matter?⁠

⁠Stephan Guyenet, PhD in neuroscience, uses the latest evidence to clearly answer this prickly question. ⁠

Intestinal Candidiasis (Candida Overgrowth)

☀️Yeast is a type of fungus and a normal part of the gut microbiome. It is harmless in most people but can cause illness in certain populations. One such illness is called intestinal candidiasis (𝘊𝘢𝘯𝘥𝘪𝘥𝘢 being a genus of yeast).⁠

⁠ Intestinal candidiasis is one of those lesser-known illnesses on which it can be hard to find reliable information. Many people have never heard about it, while others make it responsible for everything that goes wrong with your body.⁠ ⁠