DESTIN, FLA. — Despite a paucity of conclusive data in the literature—including only one prospective, randomized, controlled trial—most patients perceive an association between their diet and acne.
“The majority of our patients feel diet has some influence on their acne,” Dr. Diane Thiboutot said at the meeting. Therefore, be prepared to discuss the limited evidence about acne and such potential culprits as dairy intake and high glycemic diets.
More than half of students surveyed in two studies believed there was an association. A total of 62% of 347 high school students in Greece believed diet was a cause of their acne (J. Eur. Acad. Dermatol. Venereol. 2007;21:806-10). Another survey featured more specific questions and revealed, for example, that 53% of 539 Nigerian students aged 11–19 believed eating too much butter or margarine contributed to their acne (Int. J. Dermatol. 2009;48:498-505). Eating too much fatty food was cited by 38%.
“We don't know if these things are true or not, but the perception persists,” said Dr. Thiboutot, professor of dermatology at Pennsylvania State University, Hershey.
“There has really only been one prospective, randomized, controlled trial,” she said. The trial included 43 adolescent and adult men in Australia, aged 15–25 years with a mean of 30 inflammatory acne lesions (J. Am. Acad. Dermatol. 2007;57:247-56). One group, randomized to 12 weeks of a low-glycemic-load diet, experienced a significant decrease in total lesions—approximately 50%—compared with a 25% decrease for those randomized to a control diet.
“However, patients on the low glycemic diet lost more weight, so it is hard to differentiate the effect of diet versus weight loss,” Dr. Thiboutot said.
In an observational study, investigators found no acne in certain populations with a low glycemic diet, specifically the Kitavan Islanders of Papua New Guinea and the Aché Indians of Paraguay (Arch. Dermatol. 2002;138:1584-90).
“I reviewed this paper and wrote an editorial,” Dr. Thiboutot said. “I had some reservations about it, but it was also very interesting.” One of the criticisms of this study was the gene-versus-environment argument, she added. “What if they would not have developed acne anyway [regardless of diet]?”
Other researchers have looked at a genetic basis for acne. For example, the risk of adult acne was almost fourfold greater in first-degree relatives of those with adult acne, compared with those without, in another observational study (Br. J. Dermatol. 1999;141:297-300).
“The genetic component may come in with very severe acne,” Dr. Thiboutot said. “How many of you see a teenager with severe acne and you turn and look at the parent, and you see evidence of scarring?” Ask about family history of acne, and if it is positive, more aggressive treatment may be warranted, she said.
Epidemiologic evidence of an association between diet and acne includes two studies about dairy intake. The first assessed intake and acne in girls (J. Am. Acad. Dermatol. 2005;52:207-14). The prevalence of acne correlated with total milk intake (multivariate prevalence ratio, 1.2) and intake of skim milk (1.4), which Dr. Thiboutot described as “not overwhelming.”
She said, “It could be recall bias. How accurately do people remember their milk intake as teenagers?”
Three years later, the investigators published a prospective study of milk intake and acne in 4,273 teenage boys (J. Am. Acad. Dermatol. 2008;58:787-93). Participants self-reported milk consumption and acne assessment. Multivariate prevalence ratios showed weak associations with total milk intake (1.2), whole or 2% milk consumption (1.1), 1% milk (1.2), or skim milk (1.2), Dr. Thiboutot said. They found no association between acne and any other dairy product.
“Clearly, prospective, randomized, controlled trials are needed to further address these questions,” Dr. Thiboutot concluded.
Disclosures: Dr. Thiboutot disclosed financial ties to Allergan, Arcutis Pharmaceuticals, Galderma, Intendis, Medicis, Obagi Medical, and Stiefel Laboratories.
Studies show only a weak association between milk intake and acne.
Source ©Maciej Mamro/Fotolia.com
“Clearly, prospective, randomized, controlled trials are needed to further address these questions,” Dr. Diane Thiboutot concluded.
Source Damian McNamara/Elsevier Medical News Group