Western Culture May Be Culprit Behind Acne: Theory
By Jacqueline Stenson

Calling into question the current medical belief that diet does not affect acne, a new report suggests that regularly eating breads, cakes, chips and other staples of Western culture may promote the skin condition.

Dr. Loren Cordain, a professor of health and exercise science at Colorado State University in Fort Collins, and colleagues arrived at their conclusion after studying two non-Westernized populations: the Kitavan Islanders of Papua New Guinea and the Ache hunter-gatherers of Paraguay.

In the December issue of the Archives of Dermatology, the study authors report that they found no evidence of acne among 1,200 Kitavan Islanders aged 10 or older, including 300 of them between 15 and 25. They ate primarily fruit, fish, tubers and coconut but almost no cereals or refined sugars.

The researchers also saw no acne among 115 Ache hunter-gatherers, including 15 aged 15 to 25. Their diet consisted mostly of the root vegetable sweet manioc, peanuts, maize and rice, as well as some wild game. About 8% of their diet was made up of Western foods such as pasta, sugar and bread. Previous studies also have found that acne is rare or nonexistent in people living in non-industrialized cultures but tends to appear when they transition to a Western way of life, the report indicates.

In Western cultures, studies have indicated that acne affects 79% to 95% of adolescents and persists into middle age in 12% of women and 3% of men.

While genetic factors are known to play a role in acne, the authors point out that other groups of Pacific Islanders and South American Indians who live in more Westernized settings have higher rates of acne.

So the investigators turned their focus to environmental differences that might contribute to acne. "The most likely environmental factor that can elicit the hormonal cascade underlying acne is dietary in nature," Cordain told Reuters Health. "High-glycemic-load carbohydrates have been demonstrated to cause the exact hormonal changes known to occur with acne."

He said there is evidence to suggest that high-glycemic carbohydrates--those that substantially boost blood sugar levels--"set off a series of hormonal changes known to underlie the development of acne."

Elevated blood sugar leads to increases in insulin production, Cordain explained. This affects other hormones that ultimately can cause excess oil in the skin to be produced, pores to be clogged and bacteria that cause acne to thrive, he said.

High-glycemic foods include cereals, bagels and other breads, doughnuts and cakes, crackers, chips and candy.

Low-glycemic diets, including plenty of fruits and vegetables, might offer a new treatment option for people with acne, Cordain suggested.

However, this remains to be proven, note the authors of an accompanying editorial.

"Whether adherence to a diet with a low glycemic load can alter acne in other populations is unknown," write Dr. Diane Thiboutot of Hershey, Pennsylvania, and Dr. John Strauss of Iowa City, Iowa.

And while observations suggest that acne can develop in groups such as Eskimos who didn't have the skin condition until they started eating more high-glycemic foods, the editorialists add, "no systematic studies are available to fully support or refute these observations."

SOURCE: Archives of Dermatology 2002;138:1584-1592.