Vegetables reduce tobacco toxins
04/08/02
SAN FRANCISCO, Apr 07, 2002 (United Press International via COMTEX) -- Smokers who eat at least two servings of cruciferous vegetables a week have lower levels of tobacco-related toxins in their urine, cancer researchers told a conference Sunday.
The vegetables, which include broccoli, cauliflower, Brussels sprouts, and dark greens such as turnip and collard greens, appear to change the way smokers metabolize tobacco smoke, said Dr. Gina Day Stephenson of the American Health Foundation, Valhalla, N.Y.
Stephenson said other researchers have reported increased cruciferous vegetable intake was associated with a lower rate of smoking-related cancers.
"But this study suggests that just normal dietary levels can reduce the levels of tobacco-related toxins," she said in an interview with United Press International.
Stephenson presented her results at the annual meeting of the American Association for Cancer Research.
The study included 161 disease-free smokers aged 18 to 59; half were women and 43 percent were African American. All were asked to fill out a detailed smoking history and food frequency questionnaire. Stephenson and her colleagues measured urine concentrations of three byproducts of tobacco: two called NNAL and NNAL-Gluc, and a third called cotinine.
People who ate fewer than two servings of cruciferous vegetables a week had higher urinary concentrations of the tobacco toxins but the levels "begin to drop when people consume two or more servings," she said.
Stephenson said a typical serving is "about the size of a fist." Some studies have suggested smokers "are less likely to eat fruits and vegetables," implying a typical smoker might not eat two servings a week.
Andrew Burdick, an epidemiologist from the University of New Mexico, told UPI there are several studies that suggest the intake of "fruits and vegetables can reduce the risks associated with environmental carcinogens, including secondhand smoke."
Burdick added, however, "This doesn't mean that smokers should be advised to just eat healthy. The best way to lower risk is to stop smoking."
Burdick was not associated with the study.
Stephenson agreed the findings should not be interpreted to "indicate that smoking is all right as long the smoker is eating broccoli as well."
The United States Public Health Service funded the grant.