Largest Study Says Obesity Shortens Life

A study of more than 1 million Americans provides the most convincing evidence yet that simply being overweight can cut your life short. The largest study ever conducted on obesity and mortality found that overweight people run a higher rate of premature death. And this was true even among people who didn't smoke and were otherwise healthy during their middle years.

The study was conducted by the American Cancer Society and published in today's issue of the New England Journal of Medicine.

It settles once and for all any lingering questions about whether weight alone increases the risk of death and disease, said JoAnn Manson, a Harvard University preventive health specialist. "The evidence is now compelling and irrefutable," Manson said. "Obesity is probably the second-leading preventable cause of death in the United States after cigarette smoking, so it is a very serious problem."

The study found an especially clear association between excess weight and a higher risk of dying from heart disease or cancer. And unlike a similar study last year that suggested being overweight is less of a problem as people grow older, this study found many more deaths among overweight people of all ages, especially those over 75.

More adults and children are overweight than ever, with 55 percent of American adults weighing more than they should, 150 pounds and up for a 5-foot-5 woman and 174 pounds for a 5-foot-10 man.

"The message is we're too fat and it's killing us. We need to come up with ways as a society to eat less and exercise more," said American Cancer Society epidemiologist Eugenia Calle, lead author of the study.

Less Acid Rain Falls, But Lakes Still Acidic

Environmental regulations have reduced acid rain but have not yet spurred the recovery of damaged lakes and streams in North America, according to a study from the Environmental Protection Agency published in today's issue of the journal Nature.

The study is the first to show that reductions in sulfur dioxide emissions are directly related to reduced acidity in lakes and streams in Europe. As for the United States, which imposed regulations later, researchers said the payoff probably is still in the future.

The study, which could have important implications for efforts to further restrict sulfur emissions, examined acidity in 205 lakes and streams in five regions of North America and three regions in Europe from 1980 to 1995. It found that the amount of acidic sulfates entering lakes and streams has declined everywhere, chief author John Stoddard said.

The data also showed a drop in acidity of lakes and streams in Europe and a North American region that includes eastern Maine and southern Nova Scotia. However, no such recovery appeared in four other regions covering much of the area from eastern Manitoba through the upper Great Lakes to Quebec and Vermont.

Stoddard said recovery in North America was apparently stalled because the capacity of the soil to neutralize the acid was being depleted as fast as the sulfate levels were dropping. That's what happened in Nordic countries during the 1980s, Stoddard said.