 Chocolate has been long maligned when it comes to acne, but is it the cocoa itself or the sugar and dairy that come with it that causes acne? Watch to find out. Acne affects nearly 1 in 10 people in the world, making it perhaps the eighth most prevalent disease worldwide. What's the role of nutrition? Well, go back a century, and dermatology textbooks were recommending various dietary restrictions, for example, recommending those with acne-avoid foods like pork, sausage, cheese, pickles, pastries, sweets, cocoa, and chocolate. Yeah, but old-timey medicine was full of crackpot theories. Dr. Kellogg, for example, blamed acne on masturbation. Nothing a few corn flakes couldn't fix, though. Population studies have found associations between acne and the consumption of foods like dairy, sweets, and chocolate, but you don't know if it's caused an effect until you put it to the test. There have been high-quantity reports, like the Harvard Nurses study, that looked at nearly 50,000 women and found a link between adolescent milk drinking and acne, particularly skim milk, something that's been found for teenage boys as well. They thought it might be the hormones in milk that were responsible, but it could also be the milk protein whey of which they had extra to skim milk to make it less watery, which may play a role directly in acne formation or as hormonal carriers. That would explain cases like this, where whey protein powders were implicated in precipitating acne flares in teens who had acne that just didn't seem to want to go away, until they stopped the whey. It doesn't appear to just be a protein effect, since soy protein supplements, for example, did not seem to cause the same problem. But for dairy in terms of interventional studies, all we have are these kinds of case series. If you do a systematic review of acne and nutrition, you get results like this for dairy. Out of the 20 or so papers on acne and dairy out there, about three-quarters suggest adverse effects, and the remainder report no effect, with no studies suggesting a beneficial effect of dairy on acne. So you could look at this and conclude that dairy-free diet is worth a try, but this is based on low-grade evidence, level C and D evidence, where C is like the population studies, and D are like those series of case reports. What we want ideally are randomized, interventional studies, level A and B evidence, which we don't have for dairy, but we do have for chocolate. When it comes to acne, no food is more universally condemned than chocolate. So if you're the Chocolate Manufacturers Association, how are you going to design a study to make your product not look so bad? Well, you can always use the old drug company trick of pitting your product against something even worse, and so they fit people chocolate bars versus fake chocolate bars made out of a partially hydrogenated vegetable oil, trans fats. So you make it have more sugar, throw in some milk protein and make it 28% pure trans-fat-laden Crisco-like vegetable shortening. And surprise, surprise, there were just as many pimples on the fake chocolate bars, allowing them to conclude that eating high amounts of chocolate is AOK when it comes to acne. And the medical community fell for it. Have we been guilty of taking candy away from babies? Too many patients harbor the delusion that their health can somehow be mysteriously harmed by something in their diet. That original study, finding that chocolate consumption supposedly does not exacerbate acne, has continued to remain virtually unchallenged for decades and continues to be cited even in recent reviews. For example, this Pediatrics Journal years ago was demonstrated that chocolate consumption has no effect on acne. This serves as a cautionary example of how research-based evidence should be vigorously scrutinized prior to being incorporated into clinical practice. Just because something is published in the Journal of the American Medical Association doesn't necessarily mean it's a good study, especially when industry interests are involved. Maybe we should be telling acne patients to try cutting down on not only the sweets and the dairy, but also the trans fats found in partially hydrogenated vegetable oils. But we can't be unequivocal in our advice to acne sufferers on foods to include or exclude until they're put to the test. It well-designed, randomized, controlled clinical trials, but there simply weren't any such trials on acne until now, which we'll cover next. A century ago, dye was commonly used as part of the treatment for acne. During the 1960s, however, the diet-acne connection fell out of favor. Why? Because of a study purported to prove that chocolate had no influence on acne by comparing a chocolate bar to a pseudo-chocolate bar, composed of 28% pure trans fat-laden partially hydrogenated vegetable, a substance known to increase signs of inflammation. According to that, no wonder the chocolate didn't come out looking so bad. And then there was this other study where small groups of medical students ate a variety of purported culprits, and only about a third broke out. But there was no control group to compare to. Yet these two studies, despite their major design flaws, were sufficient to dissociate diet from acne in the minds of most dermatologists. Textbooks were revised to reflect this new academic consensus, and dermatologists took the stance that any mumblings about the association between diet and acne were unscientific, and one of the many myths surrounding this ubiquitous disease. Comments such as, the association of diet with acne has been relegated to the category of myth, are commonplace in both the past and current medical literature. Yet the major dermatology textbooks promulgating this notion that diet and acne are unrelated rely only on those two flawed studies. So this current thought within the dermatology community that diet and acne are unrelated has little or no factual support. And there's reason to suspect chocolate consumption may be an issue. If you take blood from people before and after eating a cup of bars of milk chocolate, it appears to prime some of your pus cells to release extra inflammatory chemicals when you expose them to acne-causing bacteria in a petri dish. So maybe this is one of the mechanisms that could explain the effects of chocolate on acne. But how do we know it's the chocolate and not the added sugar or milk? Yes, if you survey teens on their acne severity and eating habits, there appears to be a link to chocolate consumption, but is that people sprinkling cocoa powder in their smoothies or eating dark chocolate, or is it because the added sugar and milk? Just cutting down on sugary foods and refined grains can cut pimple counts in half, and a few months significantly better than the control group, complete with compelling before and after pictures. To tease out if it was the sugar, researchers gave people milk chocolate versus jelly beans. If it was just the sugar, then acne would presumably get equally worse in both groups, but instead the chocolate group got worse, a doubling of acne lesions, whereas no change in the jelly bean group. So it's apparently not just the sugar, maybe there is something in chocolate, or is it only in milk chocolate? So far there have been no studies assessing the effects of pure 100% chocolate on acne, that is, until there were. 57 volunteers with mild to moderate acne were randomized into three groups, receiving white chocolate bars, dark chocolate bars, or no chocolate bars every day for a month. And this wasn't just dark chocolate, but 100% chocolate, meaning like bakers chocolate. Unlike pure dark chocolate, white chocolate is packed with sugar and milk, and indeed acne lesions worsened in the white chocolate group, but not in the dark chocolate or control groups. So in this study, white but not dark chocolate consumption was associated with an exacerbation of acne lesions. But other studies did show acne worsening on dark chocolate, give research subjects a single big load of Giordele baking chocolate, and they broke out within days, a significant increase in the total average number of acne lesions within four days. And same thing with more chronic dark chocolate consumption, a half a small chocolate bar a day for a month, and increased acne severity was reported within two weeks, with before and after pictures looking like this. OK, but what was lacking in these two studies? Give people chocolate every day and their acne gets worse, or one big load of chocolate in their acne gets worse. What didn't these studies include? Long-time nutrition facts followers should know this by now. Right, they're missing a control group. If you look at surveys, most people believe chocolate causes acne, so if you give people a big load of chocolate, maybe just the stress and expectation that they're going to have an outbreak contributes to the actual outbreak. To really get to the bottom of this, you'd have to design a study where you give people disguised chocolate, you expose people to chocolate without them knowing it, and see if they still break out. Like you could put cocoa powder into opaque capsules so they don't know if they're getting cocoa or placebo, and that would have the additional benefit of eliminating the cocoa butter fat factor. No milk, no sugar, no fat, just pure cocoa powder in capsules versus placebo. But there's never been such a study until now. A double-blind, placebo-controlled study assessing the effects of chocolate consumption, actually cocoa powder consumption, in subjects with a history of acne, assigned to swallow capsules filled with either unsweetened 100% cocoa, or a placebo of like an unflavored unsweetened jello powder. Just a one-time binge requiring the swallowing of up to 240 capsules to try to secretly expose people to a few ounces of cocoa powder, and the same significant increase, the same doubling of acne lesions within four days, like in the Giardelli study. So sadly, it really does appear that an acne-prone individual is the consumption of cocoa may cause an increase in acne. Now the study did just include men, so they didn't have to deal with cyclical hormonal changes, and it's hard to imagine that the real cocoa group after swallowing hundreds of capsules didn't burp up some cocoa taste and no, they were not just in the placebo group. But the best available balance of evidence does suggest that if you're bothered by acne, you may want to try backing off on chocolate to see if your symptoms improve.