Tuesday, February 27, 2007

High-fat dairy foods may help some women get pregnant

Women having trouble getting pregnant because they aren't ovulating regularly may want to drink a daily glass of whole milk and skip the skim, according to a Harvard study appearing in tomorrow's issue of the journal Human Reproduction.

Dr. Jorge E. Chavarro and his colleagues at the Harvard School of Public Health followed 18,555 women in the Nurses Health Study II for eight years. They found that eating low-fat dairy foods may increase the risk of infertility from a lack of ovulation by 85 percent while eating high-fat dairy foods may decrease the risk by 27 percent.

The findings are important in light of government recommendations to consume three or more daily servings of low-fat milk or other dairy products, the article says, calling it a "strategy that may be deleterious for women planning to become pregnant."

For both high-fat and low-fat foods, the effects showed up with only one or two servings per day, Chavarro said.

"The women in the study really did not consume that much high-fat dairy food, but the level they did had some protective effect at about one serving a day, especially for whole milk and to a lesser extent for ice cream," Chavarro said in an interview. "It was not really high, not going crazy with buckets of ice cream after every meal."

Lack of ovulation is a significant cause of infertility, affecting as many as 1 in 3 women who have difficulty conceiving, said Dr. Alan Penzias, director of the reproductive endocrinology fellowship at Beth Israel Deaconess Medical Center and a professor of obstetrics and gynecology at Harvard Medical School. He was not involved in the study.

A number of conditions, including big swings in weight, can shut down ovulation. If a woman has gained weight recently, she is typically told to go on a diet, he said. But now that advice may be adjusted when it comes to dairy foods.

"Instead of just telling them, lose weight, we may then modify some of our advice," he said. "We may say, 'While trying to have a well-balanced healthy diet, you may want to avoid an excess of low-fat dairy foods.' "

Chavarro said dairy fat -- or something in dairy fat -- is responsible for the benefit. Hormones from cows that are soluble in fat may have an impact on fertility, but further studies will have to be done to be sure, he said. The study also looked at calcium, phosphorus and vitamin D but found no connection to infertility.

Should doctors order ice cream for their patients?

"Ice cream may be great for sensational headlines, but it's not the best dietary advice," Penzias said.

Posted by Elizabeth Cooney at 07:00 PM

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