Remember way back when I gave that spiel on how your diet can effect your skin, namely acne manifestations? As I said, those tips were based not on research but on my own experience and the advice of one internist. Since then I've done my homework. I did a comprehensive review of the literature on this topic and in August Dr. Silverberg (an esteemed Dermatologist in New York City) and I published that review (See attached journal article). Since most of you will never lay eyes on a Cutis Journal I'll provide the high points.
The literature shows that acne has clearly defined associations with consumption of Dairy (milk, cheese, ice cream, yogurt, etc.) and High glycemic index foods (refine sugars, simple carbohydrates). Here's why... Dairy products contain bovine hormones which increase your IGF-1 (a growth factor) which causes an increase in androgens (i.e. sex hormones like testosterone). Similarly, a rapid rise in blood sugar secondary to high glycemic index foods also increases IGF-1 and subsequently androgens. Androgens cause an increase in sebum production from the glands in your skin. This clogs your pores and allows for the acne bacteria to grow causing acne lesions.
Many other foods have been studied in less detail.
Chocolate, or simply cocoa, has not shown to be associated with acne but perhaps the milk in milk chocolate or the sugar content could play a role in the activation of acne symptoms. Oily and fatty foods have not been studied in much detail and their role in acne is still uncertain.
So in summary, those who suffer from severe symptoms of acne should limit the intake of dairy, while supplementing with calcium and vitamin D, and refined sugars. Hope that helps! -B
Click here for Journal Article