Does diet contribute to acne? | Anne Marie McNeill M.D. Ph.D

One of the most common questions my acne patients ask is what role the food they eat has on their acne.  It is hard to answer for any individual; acne has a variety of triggers, including genetic, hormonal, and mechanical factors.  These seem to be the most common triggers for most patients. However, there is emerging evidence that for at least some patients, diet can be a factor for causing acne.
The observation that Pacific Islanders developed acne only after adopting more Westernized diet patterns contributed to this theory.
Further, there are small studies that show a link between acne, chocolate, high glycemic index diets, and high dairy intake. I do suggest that anyone experiencing acne try to reduce high glycemic index foods and completely eliminate chocolate from their diet for 3-4 weeks.  This is good for general health.  In general, if chocolate is a trigger for you, you will see less acne within days after stopping chocolate intake.
Dairy is an important food group, and I do not recommend eliminating dairy just because of acne.  Teenagers and women in particular need calcium and vitamin D for general and bone health, and restricting this could be harmful.  For this reason, I would like to go into the data about dairy and acne in a bit more detail.
There are now several studies which show that lowfat/skim milk consumption correlates with having acne.In contrast, whole milk consumption does not correlate with having acne.
We don’t completely understand how lowfat and skim milk might trigger acne.  Low fat and skim milk have less calories and fat than whole milk, but more sugar.  It is possible that the sugars in lowfat and skim milk stimulate sebaceous glands in the skin via transient elevations in insulin and insulin-like growth factor-1.   It’s also possible that the fats in whole milk may be acting directly on cells, working on the liver and muscle to improve their ability to break down sugar from food.
Personally, I am very acne prone and have taken 2 courses of isotretinoin to reduce my acne.  However, if I have one small chocolate, I will consistently develop an acne cyst the next day.  I switched to whole milk about 2 years ago (I drink a lot of milk) and have observed that my acne is greatly reduced.  I have not gained any weight since switching to whole milk.  Some research suggests people who consume full-fat dairy weigh less and are less likely to develop diabetes, too.
In conclusion, I think it is reasonable for acne patients to try to eliminate chocolate, reduce high glycemic index foods, and replace skim/lowfat milk with whole milk.  These changes are in general healthy, and may reduce acne.  If acne persists, it is time to come in for a consultation.  Luckily, there are a number of topical, oral and laser treatments for stubborn acne.