It’s here. The day we’ve all been dreading. Recently published double-blinded study shows chocolate causes acne. The researchers showed that a single binge of chocolate increased the number of pimples by whopping 169% in a matter of days.
The role of chocolate in acne has been controversial, to say the least. In 1969 Fullerton and colleagues published a crappy study that showed chocolate has no effect on acne, and ever since dermatologists have insisted neither chocolate nor diet in general has any effect on acne. In an earlier post I wrote about a preliminary and unpublished results that showed a massive increase in acne after consumption of pure cocoa. I didn’t want to believe it and at that post I wrote that it’s unlikely chocolate causes acne.
I may have been wrong.
University of Miami researchers followed their preliminary results with a little bit better study that was published in the May 2014 issue of The Journal Of Clinical And Aesthetic Dermatology.
Study shows chocolate increases acne by 169%
The study was designed to answer what happens after a binge consumption of chocolate. They recruited 14 men, aged between 18 and 35, and gave each participant 6 1oz capsules to consume in one sitting. In total every participant consumed 6oz (170g) of capsules. The capsules were filled either with pure cocoa or gelatin.
Each participant was handed a mixture of capsules in a way that stepped up the dose of cocoa from 0oz to 6oz. So one person received 6 gelatin capsules, another 5 gelatin and 1 cocoa, and all the way to 6 cocoa capsules.
Here are the results, measured as the number of inflammatory and non-inflammatory (blackheads, whiteheads, etc.) pimples. Day 0 is the day the participants consumed the capsules.
Source: Caperton, et al. Double-blind, Placebo-controlled Study Assessing the Effect of Chocolate Consumption in Subjects with a History of Acne Vulgaris. J Clin Aesthet Dermatol. May 2014; 7(5): 19–23.
The number of both inflammatory and non-inflammatory pimples skyrocketed the days following chocolate consumption.
Compared to day 0 the number of non-inflammatory pimples increased by 140% and 160% in days 4 and 7 respectively. For inflammatory pimples the figures are even more grisly: 433% and 233%. Though I should say that most of the participants only had mild acne and not too many inflammatory pimples at the baseline.
It seems the participants who consumed a larger dose of cocoa also got more pimples, as the cocoa dose and number of inflammatory and non-inflammatory pimples was correlated, though the correlation wasn’t a particularly strong.
However, don’t get depressed yet. There are some fairly serious problems with the study and this may be a spurious result. I’ll explain the problems a bit later.
FODMAPs – link between chocolate and acne?
It’s not exactly clear why cocoa causes, or I should say aggravates acne. My own experience shows it may have something to do with gut health. For the past few months I’ve been going to the gym actively and taking whey protein shakes. I often mix whey protein and cocoa powder into a green smoothie. For the past 6 weeks my skin has been worse than normally and I’ve had mild constipation. I suspect it’s due to cocoa powder as I have no problems with whey protein itself.
Cocoa powder has moderately high amounts of FODMAPs, and can cause gut problems and in people with FODMAP intolerance. Other studies show people with acne have much higher rates of gut problems than people with clear skin. This may explain the connection between cocoa and acne, but we have to wait for further research to confirm it.
Earlier I also wrote about a study that showed chocolate aggravates the immune response against acne bacteria. This causes more inflammation at the skin and can also aggravate acne.
Serious problems with the study
After devastation and scraping myself off the floor, it’s time to think rationally about what these results mean.
There are two serious problems with the study: small size and no lack of proper control group. Bear with me for a minute as I explain why you can’t take this study at face value. This may turn out to be a false positive.
14 participants is a very small study and small studies are always prone to errors.
The second, and perhaps even bigger, problem is that there’s no comparison between cocoa and placebo (gelatin). To show that cocoa really caused the problem the researchers should have shown something like this: “Here’s what happened to the people who took the cocoa capsules, and here’s what happened to the people who took the placebo capsules. As you can see, the people taking cocoa capsules had much more acne than people who took the placebo capsules.”
Because we don’t have such comparison we can’t rule out other possibilities. Prof Bob in the comments mentioned this could be regression to mean. Acne waxes and wanes over time. The researchers only chose participants with very mild acne, you can see that the average number of inflammatory pimples at day 0 is less than 1. Perhaps what we are seeing is natural variation in acne and not cocoa causing acne.
The point is that we can’t say for sure that it was cocoa that caused the problem. It may have been, but we can’t rule out the other possibilities based on this study.
What does this mean? No more chocolate?
This study provides more evidence to support the idea that chocolate causes acne. Whether that turns out to be true or not is for future studies to show.
But there’s still hope even if we take this study at face value.
This study looked at binge consumption, and the participants consumed fairly large quantities of cocoa. Consuming a serving or two may not cause problems.
Ironically, dark chocolate may be the worst for the skin. Milk and white chocolates contain less cocoa. Of course they also contain more sugar and milk, but small amounts of sugar and milk may be less bad for your skin. It really depends on what your skin reacts to.
Also, this study didn’t include any women (to exclude hormonal cycles from confounding the results). But one should keep in mind that acne forums contain countless examples of women complaining about acne following chocolate consumption.
At the moment, the best we can do is to put chocolate back on the suspect foods list. Keep an eye on your skin after you eat chocolate and see if it causes problems for you.
What do you think of this? Have you noticed that chocolate aggravates acne?