Eat Right and Breathe Easy
WebMD News Archive
June 5, 2000 -- A daily dose of vitamins could offer protection from
pollutants and toxins that contribute to chronic obstructive lung disease
(COPD), the fifth leading cause of death in the U.S., according to a new
COPD is a group of diseases that includes chronic bronchitis, asthma, and
emphysema. Five million Americans over age 55 have COPD, and each year, COPD
contributes to approximately 10 million doctor office visits and 2 million
hospitalizations. The leading cause of COPD is cigarette smoking.
COPD is progressive and is characterized by gradual loss of lung function.
Experts say that in its early stages, and before lung damage occurs, the
disease can be reversed if the smoker kicks the habit. Later, the disease
becomes irreversible, as healthy lung tissue is lost forever.
The study investigates an association between lung function and a diet high
in vitamin C, vitamin E, carotene, and selenium. All are antioxidants,
substances that can counteract oxidants -- harmful natural and unnatural
chemicals in our environment -- and protect cells in the body.
"Our study does show that consuming higher levels of antioxidants is
related to better lung function," author Patricia A. Cassano, PhD, tells
WebMD. "It's a very strong, large study, and the findings are very clear
and consistent across the four major antioxidants we studied."
But if you're a smoker, don't think Cassano's findings point toward a magic
bullet. "The most important cause of COPD is cigarette smoking -- and the
most effective prevention strategy is to get people to quit smoking," says
Cassano, who is assistant professor of nutritional epidemiology at Cornell
University in Ithaca, N.Y. She co-authored the study with Guizhou Hu, PhD, a
research scientist with Biosignia Inc. of Chapel Hill, N.C.
"COPD is a very killing disease," Hu adds. "Cigarette smoking is
a principle risk factor for the disease. However, only 15% of smokers develop
COPD. What [our study] suggests is that there is some other factor that's very
important. We were looking at whether nutrition plays a role, specifically
Their study involved more than 16,000 men and women -- but primarily men,
with an average age of 46 -- all healthy people, all participating in the Third
National Health and Nutrition Examination Survey supported by the National
Institutes of Health.
Participants were asked about smoking status (years of smoking, current
number of cigarettes smoked per day, years since quitting) and about their diet
and vitamin supplement intake in the preceding 24 hours. Each also was given a
blood test to determine exact levels of the four vitamins.
"We found that people with high levels of antioxidants [in their diet]
had better lung function," Hu tells WebMD. They also found the protective
effect was different depending on the smoking status and varied with different
antioxidants. "Beta carotene had a less protective effect for smokers. And
the more they smoked, the less protected they are. In fact, beta carotene
offered almost no protection for heavy smokers," Hu says. However,
"selenium provides strong protection for smokers in general.