Due to naturally-occurring hormones found in dairy products, the consumption of milk may increase the likelihood of developing acne, according to an article authored by Dartmouth Medical School dermatology professor Bill Danby. The work, "Nutrition and Acne," was published in the most recent issue of Clinics in Dermatology, the official journal of the International Academy of Cosmetic Dermatology.
Acne the overproduction of cells lining the pores of oil glands is caused by hormones from three main sources: the ovaries or testes, the adrenal glands and dairy products, according to Danby's website, acnemilk.com.
The presence of growth hormone within the body increases the liver's secretion of insulin-like growth hormone, or IGF, a chemical responsible for triggering activity in the glands responsible for the development of acne, he said.
Extensive dairy consumption can raise IFG levels within the body by 10 to 20 percent in adults and 20 to 30 percent in children, according to the article.
"Bovine and human IGF-1 share exactly the same amino acid sequence," Danby wrote in the article. "Cow milk contains IGF-1 and IGF-2 even after pasteurization and homogenization so both retain activity in consumers."
All milk even that labeled as hormone-free or organic contains at least some of the cow's natural hormones, the site states.
Every individual has a different hormone "threshold," according to the site. Once the level of hormones in the body surpasses the individual's threshold, the body begins to overproduce the chemicals that cause acne. Eliminating dairy from an individual's diet can pull hormone levels below the threshold, limiting acne from developing, according to Danby.
"The link between acne and dairy was recognized as early as 1887, and dairy restriction was part of standard dermatologic therapy through the first half of the 20th century," he wrote in his article.
Advancements in the treatment of acne such as the use of antibiotics like tetracycline drew dermatologists away from a dietary approach during the 1950s, he wrote.
Five years ago, Danby collaborated with researchers at Harvard University to establish a "solid association" between dairy intake and the prevalence of acne among high school students, he said.
The link between IGF acquired from dairy consumption and acne could have negative effects for both the dairy and acne treatment industries, according to Danby. The study, however, has not been widely publicized and has produced no direct retaliation from the industries to date, he said.
"There hasn't been a serious challenge written in any of the journals in about five years," Danby said. "There are maybe six or seven experts in the world who would be in the position to oppose [my research]."
Regina Beidler, an organic dairy farmer from Randolph Center, Vt., said she was "not overtly worried" about the study impacting dairy farmers, because consumers weigh the health benefits and potential risks of dairy products when making the decision to purchase them.
Danby said he hopes dermatologists and others who deal with acne treatment will suggest dietary restrictions that reduce dairy consumption for patients.
"[A public awareness campaign] is a good idea, but it's hard to organize," he said. "It's difficult to lead a campaign when it hasn't been totally accepted yet."