Beautiful Osa Community,
This week I cannot resist touching briefly on a subject near and dear to my heart: chocolate. But before you get too excited (Yes! Chocolate!), grab your chocolate bar, take a seat, and listen to this cautionary tale…
Back in 2015, a study was published with the following title: “Chocolate with high cocoa content as a weight-loss accelerator.” Somewhat compelling, right? It certainly was for media outlets. Headlines generated from the study included “Scientists say eating chocolate can help you lose weight,” and “Dieting? Don’t forget the chocolate”. The study tested a low-carbohydrate dietary intervention with the addition of a daily serving of 42 grams of 81% cacao chocolate against the same low-carbohydrate intervention without chocolate, and there was also a “control” group who were instructed to eat as usual. After a period of 3 weeks, the low-carb group with chocolate was shown to have 10% greater weight loss than the low-carb without chocolate group. Sounds pretty good.
In truth, the study’s lead author was not a researcher but rather a science journalist who designed and sought publication for the study to reveal just how easily bad science can translate to catchy headlines. The “institute” he claimed to work at was really just a website he created, and the journal which published the study is on a list of predatory journals–meaning, not relying on the peer review system and not to be trusted. Moreover, and most importantly, the study methodology had numerous red flags which made it ostensibly bad science and which most media outlets did not care enough to explore. Among the biggest of these flaws was the use of a technique called “data dredging” or “fishing,” in which many endpoints are studied with the hope that at least one of them will show an effect. Of course, probability tells us that the more times we try something, the likelier we are to succeed, which is why this is not acceptable by quality research standards. Think of rolling a die: the more times you roll it, the more chances you have to roll a 6. So, the more endpoints a researcher chooses to measure, the more likely he/she is to emerge with some change to report in at least one of those endpoints. In this chocolate study, 18 endpoints were tested–that is an awful lot! The authors found the change in fat mass was one endpoint which showed some difference between groups, so they focused on this. In actuality, the difference was 0.1% in body fat: nothing to write home about. But when it is reported in relative terms–as in “10% greater” weight loss–it sounds like something.
The publication and publicity of this study caused some waves at the time. You can check out the Washington Post article about it here.
Why am I telling you this? It’s not really about chocolate, even though studies like this do exploit our feelings about certain foods. It’s because a very important maxim I learned in my nutrition education is that health-related headlines–especially the ones that scream things you sense are too good to be true, or absolutist statements such as “Study shows this one food will obliterate your belly fat!”–need to be scrutinized or, better yet, completely ignored. There is so much more to discuss around this topic, but in the interest of your time today, suffice it to say that catchy headlines get clicks and sell news but do not often constitute the informed interpretation of scientific findings or even sound science at all–as in the case of the fake chocolate study. The truth is that no one food is going to make or break your health (which, by the way, is part of what makes even legitimate nutritional science largely incompatible with the gold standard of randomized controlled trials, which typically test a single pharmaceutical or single ingredient intervention). So, pass on that clickbait. Instead, close your eyes, place your hand on your heart, and take a deep breath: the only thing that’s not too good to be true is you, valentine 😘.
But wait. Am I really going to leave this without a single nice word about chocolate? Of course not!
Chocolate is delicious, satisfying, and generally makes me feel better about life. As much as I love research, I don’t need a study to prove those truths to me. If you really are itching for a trustworthy study on chocolate, there are indeed some to be found on PubMed, a trusted source of vetted research, including one published in 2022 examining the effects of one ounce 85% dark chocolate daily on the mood and microbiome. You can find it here. Chocolate’s positive health effects are attributed largely to the polyphenol content of cacao–this is of course why higher percentage chocolates are nutritionally superior. Polyphenols are plant compounds which serve as prebiotics (meaning they feed the beneficial bacteria in your intestines) in addition to having antioxidant activity in the body, which protects our cells from damage. Yay chocolate! But do you know what else contains polyphenols and has positive effects on your mood and microbiome?
Fruits and vegetables. (Bet you knew that already, didn’t you😉). For further reading on fruits and veggies and their effects on the gut-brain axis, check out this systematic review or this recent narrative review .
Wishing you a warm belly and a light heart this Valentine’s day.
