Diet and Acne

The Acne Diet

The number of published research papers on nutrition and acne has been greater in the last 10 years than the previous 50. This systematic review summarizes the findings.

In general, what is good for the heart is also good for the skin, except for chocolate. The flavonoids in dark chocolate improve the endothelial lining and lower blood pressure for heart health, but chocolate may worsen acne. To see if it was the sugar or the chocolate, one study supplemented groups with chocolate or jelly beans. Despite similar amounts of sugar, the chocolate group had more acne lesions. Chocolate also remained a trigger for acne when dark chocolate was studied without added milk or sugar.

Diet influences hormones that are known to worsen acne. Eating a high glycemic diet triggers excess insulin, which causes weight gain and inflammation. The sugar load in fruit juices, soda, processed foods, and products made from white flour have a similar effect. Dairy is rich in estrogens, androgens, IGF-1, and bovine growth hormone. Both whole and skim milk contain acne-causing hormones, and, lastly, saturated fat from non-dairy sources also poses an inflammatory risk.

A Summary of the Acne Diet

Foods to Avoid in Descending Effect 

• Dairy products.
• Foods with a high glycemic index and load. These are mainly sugar void of fiber and include candy, breads and other baked goods made from white flour, rice, fruit juices, soda, and processed foods.
• Saturated fat from excess red meat and fried foods.
• Chocolate.
• Although not a food, mental stress is also a known trigger of acne. This is made worse if we eat the above foods when under stress (stress eating).

Foods to Eat to Avoid Acne

• Whole vegetables and fruit.
• Essential fatty acids found in cold water fish and oily plants like flax seed, nuts, and avocados.
• Less acne has been associated with eating the Mediterranean diet, which includes the above foods with high fiber, whole grains, and olive oil.

Coming from someone who has designed and published a study (which was cited in this review) about chocolate consumption and acne, diet studies are perhaps some of the most difficult investigations in medicine. Nutritional research relies heavily on dietary recall, which is fraught with limitations, bias, and confounding variables as people tend to underreport “bad” foods and overreport “good” foods, while not paying close enough attention to ingredients and portions. Some critics of diet-based studies even go as far to claim that they do not follow the scientific method and should be regarded as pseudoscience. Despite these shortcomings, dietary advice that drives government policy comes from these kind of studies. Luckily, over the past decade, there has been a newfound renaissance of dietary research in the dermatology literature.

In this systematic review between January 2009 and April 2020, the authors evaluated 42 observational studies and 11 interventional clinical trials and found multiple dietary factors associated with acne. Specifically, the review found that acne-promoting factors include high GI/GL food, dairy products, fatty food, and chocolate, whereas acne-protective factors include fatty acids as well as fruit and vegetable intake.

High GI/GL foods lead to hyperglycemia and hyperinsulinemia, which induce elevated levels of IGF-1, thereby promoting keratinocyte hyperproliferation and increased androgen levels, which lead to hyperseborrhea and acne. Interestingly, the authors found that the advantages of low GI/GL diets are largely negated without concomitant weight loss. Dairy products (especially whole milk), generally need to be consumed at least 3 times weekly to exert a detrimental effect. Although milk has a low GI, its hormonal components paradoxically increase glucose and insulin, leading to the same downstream effects of increased IGF-1. In terms of fatty food, at least a daily intake of fried, spicy, oily, and fast food and saturated fatty acids and trans fatty acids were needed to elicit an acne-promoting effect. Chocolate, regardless of whether it was milk chocolate or 100% cocoa, was implicated as an aggravating and exacerbating factor for acne. Conversely, the review found that frequent (more than 3 days/week) fruit (green bananas, watermelon) and vegetables (yellow, green leaf, cruciferous, green peas) showed a protective role for acne, which was attributed to their anti-inflammatory and antioxidant properties. Furthermore, the Mediterranean diet (rich in fruits and vegetables) compared with the typical Western diet is considered by the authors to be a “food model” for acne patients.

In the real world, diet and dermatology-related questions are common, almost daily, discussions that I have with patients in my clinic. Many of my patients have expressed frustration that previous providers did not take their claims seriously. Instead of quickly dismissing my patients concerns due to lack of convincing well-designed studies, I listen. These types of discussions tend to go better when shifting the doctor–patient relationship from paternalistic to collaborative. To help better validate my patients, I recommend that they keep a food diary, which can help identify dietary patterns around skin condition flares, and, more times than not, we find something.