A diet rich in fruits and vegetables appears to provide protection against lung cancer, according to research published on Tuesday.
The agents believed responsible are plant-derived compounds known as phytoestrogens found in soy products, grains, carrots, spinach, broccoli and other fruits and vegetables, the report from the University of Texas M.D. Anderson Cancer Center in Houston said.
The compounds have been shown to have a protective effect against some solid tumors but there has been little research focused on dietary intake and lung cancer, the study added.
“Our main findings were that patients with lung cancer tended to consume lower amounts of phytoestrogens” than healthy people without the disease, the report said.
The apparent benefits were found in both people who never smoked and those who were still smoking — but it was less evident in people who had quit smoking, for reasons that were not clear, the report added.
Smokers are 20 to 30 times more likely than non-smokers to contract lung cancer, one of the deadliest types of cancer, according to U.S. government figures.
The findings were based on a look at 1,674 lung cancer patients and 1,735 matched healthy people with similar backgrounds who were interviewed from July 1995 through October 2003.
IMPORTANCE OF DIET
The study was published in this week’s Journal of the American Medical Association, along with an editorial from researchers at Dartmouth-Hitchcock Medical Center in Lebanon, New Hampshire, who said doctors need to talk more with their patients about the importance of diet in preventing cancer.
“Patients should be informed that they may further reduce their risk of developing cancer by adopting a diet rich in fruits and vegetables,” the editorial said.
In a related study published in the same issue researchers at Copenhagen University Hospital in Denmark said heavy smokers — defined as those who go through more than 15 cigarettes a day — can reduce their lung cancer risk by cutting back, although the reduction is not proportional.
“A smoker who cuts back on the number of cigarettes by half reduces the risk of lung cancer not by half, but by 25 percent. So the risk is reduced but not just as much as the number of cigarettes,” said Nina Godtfredsen, chief author of the study.
The research involved 11,151 men and 8,563 women, aged 20 to 93, who attended two consecutive examinations from five to 10 years apart between 1964 and 1988, with several years of follow-up.
“Reducing tobacco consumption from approximately 20 cigarettes per day to less than 10 was associated with a 27 percent reduction in lung cancer risk compared with unchanged heavy smoking,” the study said.
“Participants who were continued light smokers or who quit smoking … reduced their lung cancer risk by 56 percent and 50 percent, respectively, compared with persistent heavy smokers,” the researchers added.