Nov. 18, 2008 -- Smokers and former smokers who eat lots of broccoli and other cruciferous vegetables may be less likely than other smokers to develop lung cancer.

Researchers at Roswell Park Cancer Institute in Buffalo, N.Y. reported that news today in Washington, D.C. at an American Association of Cancer Research meeting on cancer prevention.

"The first thing to do is to quit smoking," because that is "still the best thing to do to reduce the risk" of developing lung cancer, researcher Li Tang, PhD, tells WebMD.

Besides quitting smoking, Tang recommends smokers and former smokers eat more cruciferous vegetables, such as broccoli, cauliflower, cabbage, kale, turnip greens, mustard greens, and collard greens -- especially in their raw form.

Tang cautions that "nothing is the magic bullet" guaranteed to prevent lung cancer. But there's no downside to eating more vegetables.

Tang's team asked 948 lung cancer patients and 1,743 people without lung cancer about their smoking history and consumption of fruits, cruciferous vegetables, and other vegetables.

Among smokers -- and especially among former smokers -- higher intake of cruciferous vegetables was linked to lower risk of lung cancer.

That doesn't mean that those vegetables prevented lung cancer. Tang's study was observational; it didn't directly test cruciferous vegetables for lung cancer prevention.

But other research has shown that compounds called isothiocyanates from cruciferous vegetables may have cancer-fighting properties, Tang notes.

The most commonly eaten cruciferous vegetables in Tang's study were broccoli, cabbage, and cauliflower. Eating those vegetables raw may be best, because heating damages an enzyme needed to activate isothiocyanates, Tang says.

In February, other researchers reported that isothiocyanates in broccoli sprout extract may have helped prevent bladder cancer in lab tests on rats.

And in July, another study showed that men who eat broccoli several times a week may be less likely to develop prostate cancer than men who don't eat broccoli.