From: Agriculture Forum [mailto:[log in to unmask]]

Los Angeles Times

Wednesday, March 28, 2007

Fertility problems seen for sons of beef-eating women

Sons born to women who ate a lot of beef during their pregnancy have a 25 percent below-normal sperm count and three times the normal risk of fertility problems, researchers reported Tuesday.

The problem may be due to anabolic steroids used in the United States to fatten the cattle, Shanna Swan of the University of Rochester Medical Center reported in the journal Human Reproduction. It could also be due to pesticides and other environmental contaminants, she said.

If the sperm deficit is related to the hormones in beef, Swan's findings may be "just the tip of the iceberg," wrote biologist Frederick vom Saal of the University of Missouri in an editorial accompanying the paper.

In daughters of the beef-eaters, those same hormones could alter the incidence of polycystic ovarian syndrome, the age of puberty and the postnatal growth rate, he said.

"It's a small effect, but it is a significant effect," said Dr. Ted Schettler, an environmental health specialist at the Institute for Global Communications in San Francisco. "It's not surprising. The more you look at dietary factors, the more you turn up interesting information about how diet during pregnancy affects lots of aspects of human health."

Six growth-promoting hormones are routinely used in cattle production in the United States and Canada: the natural steroids estradiol, testosterone and progesterone, and the synthetic hormones zeranol, trenbolone acetate and melengestrol acetate. At slaughter, not all of these hormones have been metabolized.