Health Report

THE GOOD NEWS

Older men who have slow-growing prostate cancer can avoid the impotence and incontinence that often follow surgery by avoiding the surgery. Left untreated, the disease is fatal, but men over 70 or so will most likely die of something else first.

Researchers may have found a biological explanation for bulimia. Those who suffer from the eating disorder -- which involves compulsive bingeing, followed by forced vomiting -- have low levels of the brain chemical serotonin; the discovery may point the way toward treatment.

A vaccine protects monkeys from becoming infected with an AIDS-like illness by vaginal transmission. This research may lead to a vaccine that can prevent heterosexual AIDS infection in humans.

THE BAD NEWS

Only about 33% of U.S. doctors practice general rather than specialized medicine, compared with the 50% that public-health experts consider ideal. Worse yet, the number is dropping: it could be just 28% by 2010.

Women who have six or more children run a risk of heart disease 50% higher than the average for all women. A possible reason is that pregnancy could cause hormonal changes that are bad for the heart.

The idea is controversial, but two researchers claim the 50% decline in average sperm counts over the past 50 years comes from men's increased exposure to the hormone estrogen. Sources of the estrogen, the theory goes, are milk from hormone-dosed cows and water supplies contaminated by chemical spills.

SOURCES: Journal of the American Medical Association; New England Journal of Medicine; Science; Lancet