Glycemic index associated with acne occurrence
NEW YORK — Insulin-like growth factor type 1 could be responsible for perpetuating acne, according to Linda F. Stein Gold, MD, FAAD, during a presentation at the American Academy of Dermatology Summer Meeting.
“In the 1940s and ’50s it was stressed that diet had a big impact on influencing acne, but then there were small studies done which changed our entire mindset based on not-so-good data to say that the diet and acne link was a myth,” Stein Gold said. “But now we are coming back around, and the data says there might be something here.”
Stein Gold, director of dermatology research at Henry Ford Hospital, was part of the research team in the acne treatment guidelines group that published the 2016 Guidelines of Care for the Management of Acne Vulgaris in Journal of the American Academy of Dermatology.
She helped analyze literature to determine if diet influences acne and wanted to put the debate to rest. “We scoured the literature for a year, looking at all of the data, and tried to come through with some final thought,” she said.
“Given the current data, there are no specific dietary restrictions that can be made for the management of acne, but we have data that says that high glycemic index diets may be associated with acne, and some data says dairy and skim milk may impact acne,” she said.
In two studies looking at non-Westernized civilizations that consume no dairy, no caffeine, no alcohol and a small amount of sweets, a very low glycemic index diet was seen. “We don’t see any acne in either population,” she said. “However, other factors may have influenced why they don’t have acne.”
“Why is it that glycemic index would have any influence over our acne? Why does that make any sense?” she asked. When someone eats high glycemic index foods, glucose goes up and insulin-like growth factor type 1 (IGF-1) goes up. IGF-1 increases androgens and sebum production, Stein Gold said.
In a laboratory setting, researchers took sebocytes and cultured them with IGF-1 to see what would happen to the sebocytes. They saw an increased production in sebum, which led to an increased exposure to growth factor type 1 and yielded an increased level of inflammatory mediators. “Something here is triggering the development of acne,” she said.
“To create guidelines, we want to see double-blind control trials where everything is the same and controlled. But in real life it’s hard to do that, to control everything participants eat,” Stein Gold added.
In an Australian study, researchers saw a statistically significant improvement in acne lesions among patients who ate a low glycemic index diet. What’s more, patients started to lose weight and they had less bioavailable IGF-1. At week 12 compared with baseline, researchers saw a definitive decrease in inflammation solely from the diet change.
“The data are not conclusive, but there is limited evidence that if you eat a healthy diet you will improve your acne,” she said.
In a retrospective nursing study, 47,355 female registered nurses filled out a food questionnaire and information about their acne.
If a person drank more than two glasses of milk a day, there was a positive association with acne, Stein Gold said, especially if it was skim milk.
“When we try to assimilate the data to understand what is going on with dairy, there does appear to be an association with dairy and acne,” she said.
Overall, dairy does seem to affect acne. “Skim milk, total milk and low-fat milk seem to have a positive association, and researchers found a dose-response relationship with an increase dose and increased association of acne, according to researchers in a meta-analysis,” Stein Gold said.
There was no association with yogurt and cheese.
Hormonal mediators and IGF-1 are abundant in milk, and skim milk may have higher levels of IGF-1 and whey protein, she said. “Studies are starting to look more closely at whey protein to help us understand the effect of whey protein on acne.”
“Whey supplements are everywhere,” she said. Some studies have found an association between whey protein and acne, and perhaps truncal acne. “It’s everywhere in GNC, and I even found it in my kitchen,” Stein Gold, who has two teenage boys, said.
“I don’t tell teenagers or adolescents to stay away from milk, but I do tell everyone to eat a healthy diet. I don’t say anything about dairy or milk, but if you notice a food that exacerbates your acne, avoid it,” she said. – by Abigail Sutton
Stein Gold L. Diet and acne. Presented at: American Academy of Dermatology Summer Meeting; July 25-28, 2019; New York.
Zaenglein AL, et al. J Am Acad Dermatol. 2016;doi:10.1016/j.jaad.2015.12.037.
Disclosure: Stein Gold reports relevant disclosures with AbbVie, Actavis, Allergan, Aqua, Dermavant Sciences, Dermira, Foamix, Galderma Laboratories, La Roche-Posay Laboratoire Pharmaceutique, Leo Pharma Inc., Leo Pharma US, Lilly Icos LLC, Merz Pharmaceuticals, Novartis Pharmaceuticals, Pfizer, Promius Pharmaceuticals, Roche Laboratories, Sol-Gel Technologies, Taro Pharm, Topica and Valeant Pharmaceuticals.