BOSTON – For years, much of the information that has circulated about the relationship of diet to acne has been inconsistent. And while recent studies have pointed to two aggravating factors – foods with a high glycemic index and skim milk – whether dietary changes can help control acne remains up in the air, according to Andrea Zaenglein, MD.
At the American Academy of Dermatology summer meeting, Dr. Zaenglein, professor of dermatology and pediatrics, Penn State University, Hershey, reviewed information about diet and acne dating back to the early 1930s, when reports suggested an increased risk of acne in people who were glucose intolerant. Subsequent studies looked at the role of dairy, carbohydrate, chloride, saturated and total fats, sugar, and chocolate in acne. Researchers found no acne in a study of natives of Kitava, an island in Papua New Guinea, whose diet consisted mostly of roots, coconut, fruit, and fish (Arch Dermatol. 2002;138[12]:1584-90). But genetics certainly appears to play a dominant role in acne, Dr. Zaenglein said, referring to a large twin study that found that in 81% of the population with acne, it was due to genetic factors, and in 19% it was due to environmental factors (J Invest Dermatol. 2002 Dec;119[6]:1317-22).
Dr. Andrea Zaenglein
For now, Dr. Zaenglein’s advice is to recommend a low glycemic index diet mainly of fruits and vegetables and low in saturated fats and sugars, which may ameliorate acne by decreasing weight and insulin resistance – especially in patients who already have abnormal metabolic parameters. Patients should also be advised to limit processed foods, meat, and dairy, she added.
As far as dairy and acne, it is too early to say what the impact of intervention would be “because we don’t have any great interventional studies that have been done,” she said. Moreover, it is unclear how early dietary interventions would need to be started to reduce an individual’s risk of acne, she added.“It could go all the way back to things that happened when you were born that influence your outcome,” Dr. Zaenglein said. For example, babies born prematurely are at greater risk for endocrine stressors, which lead to premature adrenarche, increasing their risk for acne, she noted.
“We really need new, better intervention studies to be able to give advice to our patients,” she said. However, conducting such studies is challenging because it is difficult for people to eliminate dairy or other types of food from their diets for a prolonged period. To date, the majority of dietary studies have been observational and have relied on subjects’ recall of what they consumed, so these studies have their own inherent problems, she added.Dr. Zaenglein’s disclosures include serving as an adviser to Anacor Pharmaceuticals and Valeant Pharmaceuticals International, and serving as an investigator and receiving grants/research funding from Anacor, Astellas Pharma US, Ranbaxy Laboratories Limited, and Stiefel, a GSK company.