I think that I am asked about diet and acne every single day in the clinic. Growing up, I remember hearing all kinds of crazy things about food and acne:
- Chocolate will give you acne
- Pizza will give you acne
- McDonald’s will give you acne
- French fries will give you acne
- Anything fried will give you acne
- Anything that tastes good to a 15 year old will give you acne
Is ANY of this true?
Diet and Acne Myths
Almost everything i heard growing up about acne is completely bogus. Myths are hard to dispel. In medicine we like to dispel myths through research. A quick search of Pubmed shows that there have been about 250 studies of acne and diet, but most of these studies are a waste of bandwidth to download (even cheap, cheap bandwidth).
As an example, take this recent study on chocolate and acne. Other studies looking at chocolate and acne have not shown a relationship or have been inconclusive. These authors thought that maybe an effect would be seen if you tested 100% cocoa. Not a bad idea. However, their execution was ridiculous. They looked at 100% cocoa in 10 patients who ate up to 340 grams of cocoa and then counted acne lesions 4 and 7 days later. 10 patients. This is not a study. A real study involves at least enough subjects to be statistically valid. In this case, it would take several hundred patients. This “study” is like a 7th grader turning in a theme paper on world war two that just says “we won”. The authors made a pretty graph that showed more acne lesions after eating chocolate, but the also comment that the results aren’t statistically valid. Then, they make a second pretty graph that shows a relationship between the amount of cocoa consumed and the number of acne lesions, however, it is based on something called the Pearson Correlation Coefficient which is the statistical equivalent of “looks good to me”. The only interesting thing about the study were the reported side effects of eating up to 12 oz of chocolate in one sitting- nausea, headache, and vomiting. Apparently some of these teenagers couldn’t hold their chocolate. I NEVER had that problem.
Of course, this study was talked about all over the news (apparently a statistically meaningless graph can make national news as long as its pretty and about a hot topic). But with throw-away “studies” like this out there, how on earth can anyone figure out what to believe?
Surprisingly, there is an app for that.
Diet and Acne Smartphone App
This free app lets you look at different categories of foods:
- Glycemic Index
- Whey Protein
It provides quick, fair, and critical assessments of the published literature. It also takes a variety of foods, and based on the evidence, breaks them down into “Be Careful”, “Neutral” and “Go Ahead”. Take note, that there is no “Avoid” category, just “Be Careful”. Until better studies are done, there really aren’t foods that we can say should clearly be avoided, and instead we have this list of “Be Careful” foods that remain suspicious.
Evidence that certain foods might make Acne worse:
Chocolate and Acne
Studies on chocolate and acne have all suffered from being poor quality. There is no clear evidence of a link, either good or bad. Chocolate does seem to have some other positive health effects, so who knows what the answer for acne will be.
Dairy and Acne
Several studies have looked at milk and acne. Milk consumption seems to worsen acne, but the effects are modest. The speculation is that hormone stimulating compounds in milk might be the cause. Interestingly, skim milk was found to be worse than whole milk, and there is some thought that processing the milk to remove fat also removes estrogens (which usually improve acne) from milk.
Since dairy is such an important source of Calcium and Vitamin D, I would not advise teenagers, especially girls to cut dairy from their diet. I can fix your acne a lot more easily than anyone can fix osteoporosis.
Fatty Foods and Acne
Perhaps the single most widespread assumption about diet and acne is that fatty foods will make acne worse. Surprisingly, there have been VERY few studies. The ones that have been done are really interesting. Omega 3 fats (good fats) like what you find in fish (salmon!) and flaxseed seem to make acne better. Since these fats tend to be anti-inflammatory, this makes sense. On the other hand, Omega 6 fats which are especially high in vegetable oils (palm, soybean, rapeseed, and sunflower) seem to make acne worse. They are known to be pro-inflammatory and associated with arthritis, inflammation, and cancer. Regardless of whether Omega 6 fats affect acne, I think we would all be better off if they disappeared from our food supply.
Glycemic Index and Acne
This is the closest thing to a junk food association that there is. Changing from a High glycemic index diet, meaning high in sugars and carbohydrates, to a low glycemic index diet made acne improve about 10% in a small trial of 43 volunteers. Its a relatively modest effect.
Whey Protein and Acne
There is a recent report of 5 teenage athletes who saw their acne worsen when they started a whey supplement to help them pack on muscle. When they stopped the whey, their acne improved. Its such a small report, so further studies are definitely needed to know for sure if there is anything here. I only make mention of it because I have been asked about it recently, so I suspect that its been written about in Muscle and Fitness or something.