9 March 2000

The Fat Hormone

by Kate Melville

Hate exercise, even the though of getting sweaty with your clothes on - then you might just have the fat hormone.

At Harvard School of Public Health researchers found that exercise lowered levels of leptin in the blood. Leptin is produced by the bodies fat cells and is thought to be directly linked to obesity .

In a normal person the average leptin level is 5.8 nanograms/millimeter. By increasing physical activity by the equivalent of about three hours worth of jogging per week per week roughly gives a ten percent lowering in leptin levels.

"We don't know yet if a high level of leptin is an independent risk factor for heart disease," says Nain-Feng Chu, M.D. "But we do know that obesity raises a person's risk of a heart attack and stroke, and our findings provide evidence that physical activity may reduce the chronic disease risk in men through changes in leptin levels."

During the project researchers examined the dietary and lifestyle habits of 268 men aged between 47 to 83. Not surprisingly those men with the highest leptin levels (14.4 ng/ml) were heavier, unfit and had bad dietary and general lifestyle habits.

It also appears that high leptin levels may also be related to elevated insulin, therefore leptin may play a role in the development of diabetes.

Harvard researchers have also experimented with the gene that manufactures leptin, turning it on and off in mice. These tests did regulate the obesity levels in the mice, but so far there have been no human trial as regulating leptin levels in humans is thought to be far more complex.

So get up off the sofa and exercise, or pray that this research has a breakthrough that is applicable to both mice and men.