My whole life I’ve I’ve been a huge fan of dairy products – milkshakes, yogurt, ice cream, cheese, you name it. My family always had these things stocked in our fridge, so I never saw anything wrong with them. I did notice, though, that I always broke out on my cheeks and forehead whenever I ate milk chocolate and custard, and I always dreaded waking up with acne after indulging in my favorite chocolate ice cream. A few months ago my friend told me that almost all of her acne was gone simply because she cut out dairy from her diet. This got me thinking – does dairy consumption and what we put into our body affect how much acne we get? The null hypothesis would be that our consuming dairy doesn’t have any real effect on acne while the alternative would be that certain foods and beverages, like cheese and milk, cause us to break out! I researched this question and it turns out that yes, dairy does play a huge role in our breakouts!
Although the relationship between diet and acne has always been extremely controversial, a study published in the Journal of the American Academy of Dermatology by Dr. Caroline L. LaRosa shows a positive association of low fat/skim milk consumption and breakouts. 225 people were recruited to participate in this study, and were divided into two groups – the control group and the group that consumed the dairy products. The study stressed that both groups of people perviously had moderate facial acne and were cleared by a dermatologist to participate in the study so that it was as unbiased as possible. Both groups were given low fat/skim milk, but the control group was given a significantly smaller amount. The result? Although both groups consumed dairy, the control group, or the group that consumed much less of it, had a significantly smaller amount of acne on their face compared to the group that consumed more dairy. It should be noted that both groups started off with relatively the same amount of acne on their faces. Although the study was able to make associations between dairy consumption and acne, it was unable to determine causation, so we don’t know the mechanism, or why this occurs.
A conjectured mechanism as to why dairy might cause acne is that it is a high-glycemic-index food group, and regular consumption of foods with a high glycemic index elevates serum insulin concentrations, which may stimulate sebum production. Sebum is an oily secretion from the sebaceous glands that, when the body produces too much, causes us to break out.
Just a few years ago, scientists knew almost nothing about dairy’s effects on our skin, but so many studies have been conducted since then that Dr. Whitney P. Bowe of SUNY Downstate Medical Center published a meta-analysis in the Journal of the American Academy of Dermatology of the results. In her meta-analysis, she talks about twenty different studies that were conducted that more or less had the same results; either increased consumption of dairy increased the non-control group’s amount of acne, or decreased consumption of acne decreased the control group’s amount of acne. I do not believe that this topic suffers from the file drawer problem because the accepted idea today in science is that dairy consumption does cause acne, so if a scientist conducted a study and found no correlation between the two, they would definitely want to publish that. To my knowledge, not many studies like that exist. This is why this issue does not suffer from the Texas Sharpshooter problem, either. There isn’t just one study that claims that dairy consumption causes acne, there are many. There have been too many positive correlations between the two, so no one positive result is being emphasized as being correct.
Something that we always have to worry about when it comes to science is anecdotes. A great example of this was the video that we watched in class about a woman who claimed that a vaccine caused her to be disabled, impairing her speech and forcing her to jerk violently when walking forward. Not only was this proven to be a hoax later on, but your chances of getting a life threatening reaction due to a vaccine, the small pox vaccine for example, is 30 in 1,000,000. I found many blogs online that bolstered about the authors’ positive experiences with cutting out, like this one titled “I Gave Up Dairy And All I Got Was The Best Skin Of My Life”. Although anecdotes should not be anyones primary reason for doing anything, this topic has much extensive research and results showing that cutting out dairy does, in fact, reduce acne. Since dairy is not an absolute necessity to our diet and someone seeing these results has struggled with acne, it would be worth a shot to see if avoiding dairy would in fact help them stop their breakouts.
From these results, we can reject the null hypothesis that our diet doesn’t have any real effect on acne. Next time you’re breaking out and notice that you’re eating too much ice cream or butter, try switching them out with fruits and vegetables and see if there’s a major difference in your skin!