THURSDAY, May 5, 2005 (HealthDay News) -- Smokers who quit should make an extra effort to avoid gaining weight because those extra pounds can hurt lung function, new European research indicates.
In what appears to be the first major study to assess the impact of additional weight on ex-smokers' lungs, researchers from 13 countries, using data from more than 6,600 people in 27 countries found a strong link between the two elements, particularly in men.
For every kilogram (2.2) pounds of weight gained by a male ex-smoker, lung function decreased by 11.5 milliliters. For women who were ex-smokers, the decrease was 3.7 milliliters for every extra kilogram of weight. Overall, the study concluded, weight gain "diminished the benefit of quitting by 38 percent in men and by 17 percent in women."
But the finding shouldn't deter smokers from quitting, said Dr. Deborah Jarvis, a senior lecturer in public health at King's College in London, a leader of the study whose results are published in the May 7 issue of The Lancet.
"Weight gain reduces the positive benefits of giving up smoking, but doesn't reduce it to nil," Jarvis said.
Jarvis and her colleagues sent questionnaires to over 6,600 people in 27 countries who were in taking part in the European Community Respiratory Health Survey (ECRHS). Their lung function was measured in 1991-1993, when most were between 20 and 44 years old, and again in 1998-2003.
Overall, the researchers found, there was a general decrease in lung function as participants in the study grew older. Smokers had a greater decline in lung function than people who never smoked or who quit. But the weight gained by ex-smokers had a direct effect on lung function, as measured by the amount of air that could be expelled with each breath.
It's long been known that people who quit tend to gain weight, Jarvis said, and some earlier studies have measured either the effect of smoking or the effect of weight gain on lung function, but "until now, no one looked at the long-term effects of both giving up smoking and weight gain."
And while the study was not designed to tell smokers who quit what they should do about gaining weight, it's well-known that physical activity can help keep pounds off, Jarvis added.
Another expert echoed Jarvis' caution on reading too much into these findings.
Smokers who want to quit should not be deterred by this, said Dr. Gilbert L. Ross, medical director of the American Council on Science and Health in New York.
"The negative impact on lungs and lung function of weight gain by smokers who quit is way, way overshadowed by the negative impact of smoking on lung function as well as every other part of the body," Ross said.
Some people who quit don't gain weight, he added, "but even in those who do, the manifold benefits of quitting are incredibly greater than any minor adverse effect of some quitters gaining weight."
More information
Reasons for stopping smoking, and help with ways to do it, are available at the National Institutes of Health.
