A diet rich in fruits and vegetables helps to provide protection against lung cancer, according to the latest research.
The agents that are believed to be 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 tumours 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 to contract lung cancer than non-smokers, one of the deadliest types of cancer.
The findings were based on a test at 1,674 lung cancer patients and 1,735 matched healthy people with similar backgrounds who were interviewed from July 1995 through October 2003.