Diet and Acne: A Possible Connection -

Sheila Krishna, M.D.

“Let food be thy medicine and medicine be thy food.” – Hippocrates (460-377 BC)

One of the most famous physicians of Western antiquity, Hippocrates, is widely considered the father of modern medicine. He wrote these words over 2000 years ago, and even today, they ring true. Modern medicine has experienced a renaissance in the field of nutrition science, as physicians, nutritionists, and researchers search for evidence based medical data to connect disease and wellness states with food, supplements, and alternative treatments.

Skin science is no exception to this trend, and dermatology has benefited greatly from increased knowledge, awareness, and interest in nutrition and skin health. While there have been long held beliefs and practices regarding skin health and diet, it is only recently that evidence based data has emerged in this area and continues to be studied on a population level.

Several specific areas of dermatology have benefited from renewed interest in nutrition and skin health. Diseases such as acne, eczema, psoriasis, and even some autoimmune disorders such as lupus have been studied for their connection to diet. The role of the gut microbiome, microorganisms that inhabit the intestines, has emerged as a large area of research interest, particularly with respect to inflammatory skin disease, and there are several active areas of investigation in this space.

Acne is a specific area of research that is considered a “hot topic” in the study of skin and diet interactions. Acne has long been connected to diet in both the lay and medical community. Prior to the development of topical and oral medications for the treatment of acne, much of early acne treatment focused on the role of diet and dietary modification. As medical science has gained mastery in the use of these medications for acne, the role of diet in acne has re-emerged as an active area of study, as more patients and physicians explore additional startegies for long term acne management.

Interest in the area of research exploring the possible role of diet in acne began with observations of acne prevalence in Western and non-Western societies. While acne is a worldwide disease, it appears to be much more common in westernized societies. Nearly 79% to 95% of the adolescent population in Western societies will experience acne along with 45% of adults over 25. Further, acne can persist or present for the first time in 12% of women in late adulthood, well beyond adolescence. In contrast, members of non-westernized, hunter-gatherer societies have much lower rates of adolescent acne and rare reports of adult acne. While genetics or skin care practices may contribute, it is postulated that diet plays a much larger role in these differences.

Many dietary factors have been studied for their role in acne. These include glycemic index, dairy consumption, high and low carbohydrate diets, gluten free diets, high protein diets, candida elimination diets, probiotics, multivitamins, chocolate, and more. It is telling that in the past 10 years multiple review articles dedicated to acne and diet have been published in major dermatology and nutrition journals. There is a great interest in diet and acne, and studies have shown that a majority of people with acne believe diet plays a role in their breakouts and are interested in and eager to learn more about dietary modifications to improve their skin.

Currently, the greatest body of evidence in the study of acne and diet exists for the role of low glycemic index diets. Glycemic index (GI) is a scale that measures the rise in blood sugar triggered by the carbohydrates in particular foods and drinks. Researchers have further refined the glycemic index as the glycemic load (GL), which takes into account the changes in blood sugar with a typical serving of a given food. A food that raises blood sugar quickly is a high glycemic index food. A food that raises blood sugar slowly is a low glycemic index food.

Low GI foods include green vegetables, fruits, raw carrots, beans, lentils and bran cereals. Medium GI foods include corn, bananas, raisins, oatmeal and multigrain bread. High GI foods include rice, white bread, potatoes, chocolate, and sugary baked goods.. Low to medium GI diets are recommended for control of weight, blood pressure, blood sugar, and abdominal girth, all of which when high are risk factors for cardiovascular disease.

With respect to acne, there are many studies that have established a connection between glycemic index and severity of acne. High GI/GL diets lead to elevated levels of insulin, which is secreted by the body in response to sugar in the blood. This release of insulin also leads to increased levels of insulin like growth factor (IGF-1). These molecules have been shown to increase sebum (oil) production and increase shedding of cells that line the sebaceous follicle leading to comedogenesis and inflammatory acne. They also increase the production of acne causing hormones and their receptors, leading to increased hormonal activation of acne.

In clinical studies, it has been shown that patients on a low GI/GL diet have lower levels of acne causing hormones, lower levels of sebum production, and less clinically apparent acne. Further studies have shown that some people with acne who are on low GI/GL diets are able to reduce their usage of oral and topical acne medications as well. Specific diets such as the south beach diet and Mediterranean diet, both of which utilize low GI/GL principles, have also been examined, and individuals on these diets have had reduced acne.

Milk consumption has also been shown to be associated with acne. Similar to carbohydrates in other foods, carbohydrates in milk elevate insulin and IGF-1, which increases acne formation through increased sebum production, inflammation of the follicle, and increased androgen hormones. Additionally, milk contains bovine IGF-1, which is identical to human IGF-1 and acts in a similar fashion.

Milk also contains several other hormonal triggers of acne as well. Clinical studies have supported this connection, with two large studies showing that all types of milk can aggravate acne, and one study showing that only skim milk may be associated with acne. Importantly, whey protein in milk and in supplements has recently been shown to contribute to acne as well.

Lastly, there have also been small studies that suggest a role for certain vitamin and supplements in the treatment of acne In one small study, intake of omega 3 fatty acids resulted in improvement of acne.

In another study, the use of probiotics along with routine antibiotic treatment for acne resulted in lower acne lesion counts. Zinc, vitamin A, and vitamin D have also been studied, but the role of these vitamins in acne remains unclear.

Nicotinamide ( niacinamide), a derivative of vitamin B3, has also been used as a supplement to improve acne, and there are several studies that support its use, though the studies are small and mainly observational. There is an FDA approved combination of nicotinamide that contains folic acid, zinc and copper that is purported to improve acne. However, caution must be used when taking these supplements, as there have also been side effects reported with high doses.

At this time, the role of diet and acne continues to be elucidated, with increasing interest in specific dietary changes that can be made to reduce acne, and lessen the need for topical and oral medications. Further research remains to be done on specific subsets of acne, such as hormonal acne in adult women, and the role of diet’s effect on the microbiome and acne is an active area of study.

The greatest body of evidence exists for low glycemic index/glycemic load diets and some evidence exists for low dairy diets. Both interventions can be considered as part of an integrated approach to acne treatment.

Studies of vitamin supplements such as vitamin A, vitamin D, zinc and probiotics have suggested their possible role in the treatment of acne, but much further research is required before recommendations can be made.

While dietary changes may not treat all types of acne or may not be sufficient to treat moderate to severe acne, further research is likely to reveal additional dietary factors that can be implemented for integrative long term acne management. An experienced dermatologist can assess the severity of acne and tailor an approach that combines conventional acne treatment with suggestions for dietary and lifestyle modification

References

Bowe, W.P., Joshi, S.S., and Shalita, A. Diet and acne. J Am Acad Dermatol. 2010; 63: 124–141

Kaymak, Y., Adisen, E., Ilter, N., Bideci, A., Gurler, D., and Celik, B. Dietary glycemic index and glucose, insulin, insulin-like growth factor-1, insulin like growth factor binding protein-3, and leptin levels in patients with acne. J Am Acad Dermatol. 2007; 57: 819–823

Danby, F.W. Acne and milk, the diet myth, and beyond. J Am Acad Dermatol. 2005; 52: 360–362

Abedamowo, C.A., Spiegelman, D., Danby, F.W., Frazier, A.L., Willett, W.C., and Holmes, M.D. High school dietary dairy intake and teenage acne. J Am Acad Dermatol. 2005; 52: 207–214

Di Landro, A., Cazzaniga, S., Parazzini, F., Ingordo, V., Cusano, F., Atzori, L. et al. Family history, body mass index, selected dietary factors, menstrual history, and risk of moderate to severe acne in adolescents and young adults. J Am Acad Dermatol. 2012; 67: 1129–1135

Bronsnick, Tara et al. Diet in Dermatology. Journal of the American Academy of Dermatology , Volume 71, Issue 6 , 1039.e1 – 1039.e12

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