A Milky Complexion

I have written several articles about the negative impact cow's milk has on your body, and most recently about its possible association with prostate cancer and cardiovascular disease. (See Daily Health News, August 9, 2005.) Now there's even more information about the downside of milk, courtesy of the researchers at Harvard and its ongoing Nurses' Health Study. This time the news is that milk does not give you a milky complexion.

More Milk, More Acne in Teens

Although the American Academy of Dermatology refers to the association between diet and acne as a myth, there remains a strong folkloric belief in the acne-diet connection. Researchers at Harvard School of Public Health set out to discover if there was any truth to it.

To evaluate the hypothesis that dairy is associated with severe teenage acne, Clement A. Adebamowo, MD, ScD, and his colleagues analyzed responses from more than 47,000 women in the Nurses' Health Study. Their research confirmed that milk -- not greasy french fries, pizza, soda or chocolate -- was the most likely dietary contributor to whiteheads, blackheads and pimples in adults and teens. Worse yet, skim milk (the kind we make a special point to drink for our health) was even more strongly linked with acne than whole milk. Other dairy products associated with acne include cottage cheese, cream cheese, sherbet and instant breakfast drinks.

In the retrospective study, researchers found that when the women were adolescents, most (61.2%) drank whole milk, 20.2% drank low-fat milk, 7.4% drank skim milk and 2.1% drank powdered milk. Only 7.7% drank no milk at all, and 1.4% of participants did not indicate the type of milk they drank. After accounting for other factors, such as age, age at menarche (first period), calorie intake and weight, they discovered that...

Women who drank more than three daily servings of any type of milk as a teen were 22% more likely to report having had severe acne than those who consumed one or fewer servings a week. Even though the study is based on "reported" acne severity versus empirical data, the 22% is so compelling that the correlation is considered to be quite strong.

In still more dramatic findings, women who drank two or more daily servings of skim milk as adolescents were 44% more likely to report having experienced severe acne than those who consumed one or fewer servings a week.

A Biological Fluid

Why does skim milk have a higher association with acne? According to Dr. Adebamowo, "In order to make skim milk more palatable to consumers, additional milk proteins are added after the removal of the fat content." This makes skim milk taste more like regular whole milk. However, the process also most likely accounts for skim milk's higher association with acne. It suggests that contrary to prior theories, the fat content of dairy products is not the complete answer to its sometimes negative impact on health: A larger issue concerns the hormones and bioactive molecules in milk. "Milk is a biological fluid, the consumption of which has an effect on the consumer apart from its role as a source of food and nutrients," explains Dr. Adebamowo.

Are Other Animal Products Bad, Too?

I asked Dr. Adebamowo about other animal sources of foods. If it all boils down to biology, then why wouldn't red meat, chicken or fish also contribute to acne? His answer: "Milk is a different kind of food. It is essentially produced by the mammary glands of mammals for the nourishment of their young." The fluid content of milk is fundamentally highly filtered plasma to which the breast contributes additional hormones.

Moderate Consumption Is Best for Teens

While all this may sour you on milk, it's not to say that teenagers should suddenly give up milk. "On the basis of this paper, it is too early to advise teens against milk," confirms Dr. Adebamowo. If and until clinical studies definitively prove otherwise, the prevailing wisdom remains that calcium-rich milk helps build strong bones in the all-important teen years.

That said, given health concerns about milk, moderation is best. Dr. Adebamowo recommends limited consumption of milk within the context of a balanced diet and daily multivitamin supplement. Soy and rice milk are good alternatives, and green vegetables (such as collard greens, turnip greens and broccoli), tofu and canned salmon with ground bones are also rich sources of calcium.

Looking toward the future, researchers consider the suggestion that hormonal constituents in milk have significant biologic effects on young women. This is one more reason for people to leave milk drinking to young cows and to get their calcium through other sources.

Be well, Carole Jackson, Bottom Line's Daily Health News

Sources:

Clement A. Adebamowo, MD, ScD, department of nutrition, Harvard School of Public Health, Boston.
American Academy of Dermatology, www.aad.org
Havard School of Public Health, www.hsph.harvard.edu