In the Sept. 28 issue of the Journal of the American Medical Association, the investigators report that study participants who ate the highest amount of foods with dietary "phytoestrogens" had a 46 percent reduced risk of developing lung cancer, compared to those who ate the lowest quantity. More than 3,500 people participated in the research - making it the largest case-controlled study to examine dietary phytoestrogens and lung cancer risk in a U. S. population, according to the researchers.
The researchers also found gender specific benefits for different classes of phytoestrogens. Men who ate the highest amount of soy-isoflavins lowered their risk of developing lung cancer by 72 percent, and women who ate the most fruit and vegetable by 41 percent. For those women who also used hormone replacement therapy, this protective effect was further enhanced.
"What we have found is intriguing and supports a small but growing body of evidence that suggests estrogenic-like compounds in food may help protect against development of lung and other cancers," says the study's lead author, Matthew Schabath, Ph.D., a postdoctoral researcher in the Department of Epidemiology. "But these kinds of studies, which rely on a person's recall of the food they have eaten months before, have known limitations, and require more investigation."
As promising as they are, the study results should not be seen as a license to continue smoking while increasing consumption of vegetables, says the study's principal investigator, Margaret Spitz, M.D., chair of the Department of Epidemiology.
"The best cancer prevention advice continues to be to stop smoking, and it is clear that all of us can benefit from healthy
Contact: Laura Sussman
University of Texas M. D. Anderson Cancer Center