Fruits, vegetables, teas may protect smokers from lung cancer

June 27, 2008
The study found that participants who ate foods containing certain flavonoids seemed to be protected from developing lung cancer.

Tobacco smokers who eat three servings of fruits and vegetables per day and drink green or black tea may be protecting themselves from lung cancer, according to a first-of-its-kind study by UCLA cancer researchers.

UCLA researchers found that smokers who ingested high levels of natural chemicals called flavonoids, water-soluble plant pigments that have antioxidant and anti-inflammatory properties that can counteract damage to tissues, in their diet had a lower risk of developing lung cancer, an important finding since more than 90 percent of lung cancers are caused by tobacco smoking.

For the UCLA study, researchers looked at 558 people with lung cancer and 837 people who did not have lung cancer and analyzed their dietary history.

The study found that:

• Participants who ate foods containing certain flavonoids seemed to be protected from developing lung cancer.

• The flavonoids that appeared to be the most protective included catechin, found in strawberries and green and black teas; kaempferol, found in Brussels sprouts and apples; and quercetin, found in beans, onions and apples.

• The antioxidant properties found in the flavonoids also may work to counteract the DNA-damaging effects of tobacco smoking, explaining why they affected the development of lung cancer in smokers but not in nonsmokers.

Should smokers run out and stock up on the teas, apples, beans and strawberries? Quitting smoking is the best course of action, said Dr. Zuo-Feng Zhang, a researcher at UCLA's Jonsson Cancer Center and a professor of public health and epidemiology at the UCLA School of Public Health.

"Since this study is the first of its type, I would usually be hesitant to make any recommendations to people about their diet," Zhang said. "We really need to have several larger studies with similar results to confirm our finding. However, it's not a bad idea for everyone to eat more fruits and vegetables and drink more tea."

Source: UCLA School of Public Health, May 29, 2008