Chocolate: What is the Optimal Dose?

Bret asked us how much chocolate is needed for good health:

I have a question about having dark chocolate daily. Does it need to be every day or what is the mininum grams per day. I have been having around 35g a day of 70% but I wondered if less would be ok or not having it at all.

This is a great time for this question, since Halloween candy will be running out soon, and those on tight budgets may be tempted to skimp on their chocolate. Should they?

Chocolate Is Not Considered Essential … Yet

Chocolate has not yet been recognized by the Food and Nutrition Board of the National Academies as an essential nutrient. We haven’t either: Our food plate lists it among “pleasure foods,” which are healthful but optional.

However, we are becoming ever-more chocolate friendly. In the new edition of our book, we list chocolate among our “supplemental foods” which we recommend consuming regularly. But our suggested dose is “as desired.” Perhaps we should narrow that down a little.

Chocolate Against Cardiovascular Disease

We’ve previously warned of the danger of chocolate deficiency, based on a systematic review that found: “The highest levels of chocolate consumption were associated with a 37% reduction in cardiovascular disease and a 29% reduction in stroke.” [1]

Here’s a visual summary of their findings:

The review authors report that every study accounted for chocolate intake in a different way, so they could only compare the groups with highest and lowest chocolate consumption in each study, not specific doses of chocolate.

Chocolate Against Diabetes

Bret was concerned about the sugar in chocolate, but if this is a problem, it’s outweighed by the benefits of chocolate. A Japanese study found that the rate of diabetes was reduced by 30% in those who consume the most chocolate. [2]

Chocolate Against Dementia and In Support of Cognitive Function

Several studies [3, 4] have found that chocolate consumption reduces risk of dementia and enhances performance on tests of cognitive function.

One of them found that cognitive function was optimized with a relatively low dose of chocolate – ten grams per day:

The associations between intake of these foodstuffs and cognition were dose dependent, with maximum effect at intakes of approximately 10 g/d for chocolate and approximately 75-100 mL/d for wine, but approximately linear for tea. [3]

The other found that cognition improved with intake of cocoa flavanols up to quite high doses – elderly given 1 g/day cocoa flavanols performed significantly better on cognitive tests than those given lower doses. [4]

Unfortunately I don’t know what fraction of chocolate is made of flavanols. I’m guessing it’s not more than a few percent, in which case this research suggests the optimal dose of chocolate may be 50 g/day or more.

Chocolate in Support of Circadian Rhythms

Most authors attribute the benefits of chocolate to their flavanols, which are thought to improve endothelial function and increase blood flow to the brain, among other effects.

However, there are other active compounds in chocolate, include peptides that interact with the opioid receptor. The opioid receptor has a role in circadian rhythms, which is one reason low-dose naltrexone (which blocks opioid function at night) works. It’s possible that eating chocolate during the day may support circadian rhythms via opioid receptor stimulation, especially if the peptides can reach the systemic circulation.

Indirect evidence that this may be beneficial comes from a Russian study in which exorphins (opioid receptor ligands) were injected into rats:

The chronic intraperitoneal administration of the peptide at the same dose of 5 mg/kg significantly increased exploratory activity, decreased anxiety, and improved learning. [5]

I don’t know how much chocolate would have to be eaten to achieve a similar exorphin dose in humans, but I imagine it’s large.

Chocolate in Support of Nobel Prizes

So how shall we resolve the issue of optimal chocolate dose? For me, the decisive evidence comes from a recent study by Franz Messerli published in the New England Journal of Medicine.

Based on chocolate’s support for cognitive function, he decided to see if chocolate consumption was related to another measure of cognition – Nobel Prize awards per capita. He counted Nobel Prizes and compared them to the recipient’s country’s chocolate consumption. These were his findings [6]:

There is clearly a strong correlation. The correlation coefficient is .79; p < 0.0001.

The correlation coefficient if Sweden is removed increases to .86 – which is suspicious:

Given its per capita chocolate consumption of 6.4 kg per year, we would predict that Sweden should have produced a total of about 14 Nobel laureates, yet we observe 32. Considering that in this instance the observed number exceeds the expected number by a factor of more than 2, one cannot quite escape the notion that either the Nobel Committee in Stockholm has some inherent patriotic bias when assessing the candidates for these awards or, perhaps, that the Swedes are particularly sensitive to chocolate, and even minuscule amounts greatly enhance their cognition. [6]

Those dastardly Swedes! Giving themselves more Nobel Prizes than their chocolate consumption warrants!

But I apologize, I’ve been diverted. The key point is, is there an optimum chocolate consumption?

the dose–response curve reveals no apparent ceiling on the number of Nobel laureates at the highest chocolate-dose level of 11 kg per year. [6]

11 kg/yr is an average of 30 g/day. So benefits are still increasing at that dose.

Of course, this was only a population level study. We still need to measure the doses in individual laureates to gain confidence. But anecdotally, there appears to be a correlation:

“I attribute essentially all my success to the very large amount of chocolate that I consume,” said Eric Cornell, an American physicist who received the Nobel Prize in 2001. “Personally I feel that milk chocolate makes you stupid. Now dark chocolate is the way to go. It’s one thing if you want like a medicine or chemistry Nobel Prize…but if you want a physics Nobel Prize it pretty much has got to be dark chocolate.”

Dark chocolate is, indeed, the PHD-approved form of this highly beneficial food.

Conclusion

This dose-response data might not be strong enough to define an RDA, but I’m going to take a stand: Bret’s intake of 35 g/day is healthy. Indeed, it’s right in line with the Nobel Prize-maximizing chocolate intake of the Swiss.

In regard to your last question, Bret – can you eat less chocolate, or none at all – the answer is clear. Yes, you can. But you must accept the consequences. You probably won’t be winning the next Nobel Prize for Physics.

References

[1] Buitrago-Lopez A et al. Chocolate consumption and cardiometabolic disorders: systematic review and meta-analysis. BMJ. 2011 Aug 26;343:d4488. doi: 10.1136/bmj.d4488. http://pmid.us/21875885.

[2] Oba S et al. Consumption of coffee, green tea, oolong tea, black tea, chocolate snacks and the caffeine content in relation to risk of diabetes in Japanese men and women. Br J Nutr. 2010 Feb;103(3):453-9. http://pmid.us/19818197.

[3] Nurk E et al. Intake of flavonoid-rich wine, tea, and chocolate by elderly men and women is associated with better cognitive test performance. J Nutr. 2009 Jan;139(1):120-7. http://pmid.us/19056649.

[4] 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 Sep;60(3):794-801. http://pmid.us/22892813.

[5] Belyaeva YA et al. Effects of acute and chronic administration of exorphin C on behavior and learning in white rat pups. Moscow University Biological Sciences Bulletin Volume 64, Number 2 (2009), 66-70, DOI: 10.3103/S0096392509020035. http://www.springerlink.com/content/qt537481061656gt/?MUD=MP.

[6] Messerli FH. Chocolate consumption, cognitive function, and Nobel laureates. N Engl J Med. 2012 Oct 18;367(16):1562-4. doi: 10.1056/NEJMon1211064. Epub 2012 Oct 10. http://pmid.us/23050509.

Leave a comment ?

142 Comments.

  1. Not the most rigorous study, but it allows me to rationalize my recently-formed habit of eating 100 grams of Lindt’s 90% chocolate every day.

    http://newsinfo.inquirer.net/204871/dark-chocolate-cuts-heart-deaths-australian-study

    The comments to this thread are very interesting, BTW. I have wondered about the copper toxicity possibility before. The anecdote about eating 900 grams of chocolate a week and living to a ripe old age also afford me some solace 🙂

    • Thomas, I also eat Lindt’s 90% dark chocolate every day — only one or two small squares though. I’d eat more, but can’t afford the calories.

      BTW I was personally offended when they discontinued the 93% cocoa bars!!! Most wonderful taste in the world IMO.

  2. Primal Snacking on the Go » PrimalTokyo PrimalTokyo - pingback on April 30, 2013 at 3:27 am
  3. Pedro Guimarães

    Hello,

    I’m eating 50g of dark chocolate(85%) everyday. But should I count this 50g as a Starch or a Sugary Plants wheight? Chocolate can have a considerable quantity of carbs… 😕

  4. Dave Daurelle

    Well reported! Thank you very much.

  5. Just wondering if you see any problem with the soy lecithin in some of the brands?

    • No. Actually lecithin from almost any source is arguably a decent nutritional supplement (for choline etc). It is the proteins in soy that I’m most concerned about.

      • Does this mean that lecithin contains no proteins? Or, that the soy proteins within soy lecithin are negligible?

        Many thanks!

  6. I’m confused about chocolate. What should we be looking for in chocolate that is healthy and what should we avoid? I bought some Fair Trade chocolate that contains the following ingredients:
    Cane sugar
    Cocoa mass (minimum 48% cocoa content)
    Cocoa butter
    Soya lecithin

    Should I be looking for chocolate without sugar?

  7. Bravo, very informative and witty. Delicious to read! Thank you.

  8. Ali:

    If you’re still monitoring this thread, sugar isn’t good for you, Soy lecithin, OK, cocoa butter okay. Try using straight coca. I’ve adapted to taste. Two tablespoons of cocoa to 8 oz. of water make a very drinkable hot chocolate. or use coconut milk straight or half-and half for a richer drink.

    Paul: Is there someone to stop the shout out messages, especially in an old thread. I continue to be interested in any substantive comments on this topic, but otherwise they are a distraction and close to spam when I’m notified by email

  9. I have noticed that my digestion worsens after having chocolate, by the way. Could it be the sugar? I get mild reflux (which I normally don’t get), and some burping and mild stomach bloating.

    I used to have some “GERD” symptoms (not so mild reflux, lots of gas and burping, and significant bloating – the lean man with a pregnant woman’s pending belly 🙂 ) That’s almost entirely gone away now with PHD and supplements and micronutrient rich foods, but chocolate brings it back.

    Any ideas? Suggestions? Get 100% and use stevia leaves if wanting sweetening? The highest% organic chocolate I can find here is 80%.

  10. I have noticed that my digestion worsens after having chocolate, by the way. Could it be the sugar? I get mild reflux (which I normally don’t get), and some burping and mild stomach bloating.

    I used to have some “GERD” symptoms (not so mild reflux, lots of gas and burping, and significant bloating – the lean man with a pregnant woman’s pending belly 🙂 ) That’s almost entirely gone away now with PHD and supplements and micronutrient rich foods, but eating chocolate brings it back.

    Any ideas? Suggestions? Get 100% and use stevia leaves if wanting sweetening? The highest% organic chocolate I can find here is 80%.

    • you may not like hearing this much, Stormsabet,

      but, from what i have read (there a few studies on pubmed), some methylxanthines, such as theobromine and caffeine, may relax &/or weaken the LES (lower esophageal sphincter) muscles.

      & guess what, theobromine and caffeine are found in dark chocolate.

      i gave up dark choc & my night time reflux (silent reflux) went away eventually…may or may not have been related.
      but you need to give it time to test, because the mechanism (imo) is that your LES muscles need time to recover/strengthen.

      • Hm, thank you! 🙂 Very happy to hear about and see re: the mechanisms of that.

        For myself, it consistently goes away when I don’t eat chocolate (though the lag time is sometimes 1-3 days) and returns when I eat chocolate (or the night afterwards)

        I’m curious whether you tried eating your chocolate towards the early hours of the day, and whether that made any difference.

        Though, I suppose that I might want to look into what mathylxanthines are, in the morning. 🙂

        Thank you – that’s very useful!

        (Science trumps somewhat pleasurable tastes any day. :))

        • *methylxanthines 🙂

        • “I’m curious whether you tried eating your chocolate towards the early hours of the day, and whether that made any difference”…

          Yes i did. at one time i was eating too much dark choc & i also knew it contained caffeine. so i decided to stop eating after 3pm.
          This did not seem to have much (any?) effect by itself.
          …But note i did Not suffer from reflux after eating.
          I self-diagnosed that my issue was more ‘posture relate’ ie. as long as my torso was upright (seated or standing) i was fine.
          But if was lying down (ie. at night) i would suffer from stomach fluids travelling the wrong way (night time breathing can also be a factor, together with lying down)…

          cont.

        • “But if was lying down (ie. at night) i would suffer from stomach fluids travelling the wrong way”…

          so hence i concluded a weak LES could be my issue.

          so i stopped the dark choc.
          i was not a coffee drinker.
          i may have stopped drinking tea (not sure), tho i am currently not drinking tea, i just kinda stopped a while back.
          non-phd alert > i also stopped drinking sugar free caffeine & guarana energy drinks.

          cont.

        • & after a few weeks my issues went away, maybe 100% by 2 months.

          Now, after a few weeks of giving them up i had started doing the occasional sugarfree caffeine&guarana energy drink again.
          & now (Paul, cover your ears) i am back drinking the sugarfree energy drink as before. But have never eaten dark choc again.

        • …& this was all 8 or 9 months ago,
          so the caffeine (& guarana) in the energy drink has not caused me any issues.

      • Now that I think about it, I wonder if you experience – or have heard of anyone else experiencing – reflux with tea or coffee.

        🙂 That’s very interesting indeed.

      • Hmm.

        This also makes me wonder: if the LES is weakened by methylxanthines in coffee/tea/chocolate, are there significant negative endpoints (diseases or problems) which show up in conjunction with the positive endpoints (such as reduced heart disease, increased mental acuity…) in heavy chocolate eaters/tea drinkers/coffee drinkers? More GERD? Esophageal problems?

        And, if not, are other foods or practices perhaps used in conjunction with tea/coffee/chocolate that somehow mediate those effects? Are the effects not very noticeable? Or, are the studies not equipped to ferret them out? Or, do too many people in the general population now have digestive system problems from general diet and lifestyle to tell whether the chocolate/tea/coffee cause them…? 🙂

        • My wife had to give up chocolate and coffee due to GERD issues. Takes time to heal the esophagus and build muscles back into the LES, as previously mentioned.

          I had no issues with GERD, but gave up chocolate and coffee because they worsened my hypothyroid symptoms. I’m not sure if it was from disruption of circadian rhythms or more direct, but quitting them also improved my mood. Seems that what goes up must come down, and I came down pretty hard and got cranky then depressed. I keep telling myself this is thyroid related, and that when it’s fully recovered I’ll be able to indulge again, but… reality has a pesky habit of interfering with fantasy. We’ll see. My TSH is creeping down very slowly.

  11. So, would you say the higher the cacao count, the better? I found a brand that’s 98 % cacao sweetened just with stevia. It’s intense!

  12. For all budding Nobel laureates who don’t want sugar to get in the way of their progress, you can easily make your own sugar-free and quite bearable-once-you-are-used-to-it chocolate as follows:
    Equal quantities of cacao butter,coconut oil and cacao powder (more or less cacao powder to taste) plus vanilla. Put cacao butter in a bowl in a pot of simmering water (no lid on) and allow to melt. Add coconut oil then when both are melted add the cacao powder and vanilla. And macadamia nuts chopped for the de luxe version. I mix it together with a hand egg-beater but I suspect you don’t have those in the U.S. so a whisk should do. Put it in trays and, when it has cooled enough, put it in the freezer. Cut before it gets too frozen and then keep it in the freezer. For wimps and the uninitiated, I do a small tray with a little honey added, but I am sure rice malt would do the job. The true chocaholic rapidly adapts to the non-sweet version (tested on family and friends) although the coconut oil takes off the edge and makes the switch to sugarless easier. Good idea to use organic ingredients unless you want to increase your lindane levels and contribute to a very low standard of living for workers on cocoa plantations.
    Rhonwen

  13. By my understanding of the PHD, one of its main goals is to minimise intake of toxins. However, I get the impression that chocolate and cacao can contain some things that are not so good for the human body, for example:

    – heavy metals (lead and chromium in particular)
    – mycotoxins, e.g. aflatoxins, ochratoxin
    – acrylamide (if the beans are roasted)

    Should these not be considered toxic? Does chocolate/cacao fall into the category in which “the dose makes the poison”?

  14. Chocolate addiction aside, we must remeber that correlations like the one above, does not mean causation. Swiss chocolate might have a lot of sugar, 10kg of sugary or not so sugary chocolate might be consumed, but whether than is (dare I say it) thrown away or added into desserts or shipped abroad, it seems unlikely that that that much dark cholocate is being consumed. Indeed the dose is the poison, same thing for coffee. It seems that a rotation perfect health diet, would give you the most benefits with the least stress on the body, particulary for allergens. Let’s also be honest, who can afford 30g of quality chocolate a day, except perhaps noble laureats? Get its beneficial amount of magnesium from a supplement and copper from liver.

  15. And flavonoids from berries

  16. Hi Paul,

    I understand the benefits of Cacao and I consume a small amount of raw cacao powder each day in a smoothie, however I’ve recently read information (Weston Price) which claims that cacao is high in phytic acid, and therefore stops our body from absorbing the essential nutrients that the cacao contains, not to mention any other nutrients in my smoothie too!

    I’m currently pregnant and following your diet and like the idea of having a low phytic acid diet.

    What’s your take on this? Does cacao contain phytic acid and if so does this mean we should comsume it alone without other foods?

    Many thanks for your time on this,
    Sarah

    • Naturally occurring phytate is usually already bound to minerals and so it doesn’t tend to chelate much else. When it does, it is often beneficial, as when it helps relieve iron excess in men or postmenopausal women. I wouldn’t worry much about it, if you are well nourished the small changes introduced by a bit of phytate won’t matter. Remember the peak health range has a flat top so you have some leeway with no impact on your health.

  17. I found a chocolate on amazon called palmil which is a dark mint chocolate DAIRY AND SUGAR FREE. it has xylitol

  18. I’m not big on chocolate, but have been buying Trader Joe’s ‘Pound Plus’ 70% bars because they’re a good deal. They’re 70% cocoa solids, so 3 squares of it – about 39 grams, would be in line with a good daily dose and provide 25 grams of cacao solids. But lately I’ve been using raw cacao powder instead. From what I read, raw cacao can have about 8 times the ORAC value of processed cocoa, so I just use about 3 grams of the powder in water when I take some of my other supplements in the morning. First make a paste with just a bit of water, as you would cement mortar, and then add the rest of the water once you’ve wetted all the powder.

    • By the way, Trader Joe has another product that those of you who aren’t chocoholics might like…’Coffee & Cocoa’ in a 12 oz. can. Really tastes great, I think. Coffee lovers should like it.

  19. As you should know, correlation does not equal causation. Another factor is likely driving both, which is likely per capita income. Countries with higher per capital income on average have higher chocolate consumption, and also greater investment in science.

    • Hi seri

      I think it’s tongue in cheek… I don’t think Paul really believes the chocolate-Nobel prize hypothesis.

      The implication would be that Scdndinavians are more intelligent than, say, Mediteranneans and that this is down to chocolate consumption! As an economist, Paul would probably agree with your more plausible theory. Although thay wouldn’t explain why the Japanese have won so few Nobel prizes. Perhaps cultural reasons also play a part.

      • I’d bet that the Japanese win fewer Nobels because they think very well inside the box.

        • you have to be joking me.

          The Japanese are too conventional thinkers by your estimate?

          You’re actually serious or is this like residual Pearl Harbor angst?

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