Q. I've heard that foods like broccoli and cabbage may help prevent cancer. Is this true?

A. As you were told as a kid, eating all your vegetables is good for you. Broccoli and cabbage, which are members of the cruciferous family of vegetables, are no exception. Other members of the cruciferous clan include kale, cauliflower, kohlrabi, arugula, brussels sprouts, bok choy, turnip greens, radishes, watercress, daikon and mustard greens. A high intake of these vegetables provides you with super-healthy nutrients that may indeed help protect you against cancer.

There's a wealth of research on the effects of compounds found in cruciferous vegetables, such as indole-3-carbinol, or I3C. These compounds may enhance breast-cancer cell death and help prevent breast cancer. According to an article published in the journal Nutrition & Cancer in 2001, I3C appears to have estrogen-blocking effects on breast cells — which makes it an important potential ally, because estrogen can stimulate the growth of breast cancer cells in some women. A study published in Cancer Research in 2003 found that I3C inhibited breast-cancer cell growth, not only in breast cancers that are stimulated by estrogen but also in those that are not. Another study, published in the International Journal of Cancer in 2006, confirmed that I3C is a potent inhibitor of breast-cancer cell growth.

Cruciferous vegetables also contain compounds with tongue-twisting names like isothiocyanates, which appear to have other cancer-fighting properties. A study published by the National Institutes of Health in 2000 strongly suggests that isothiocyanates can protect you against lung cancer. Some people have a gene that quickly breaks down isothiocyanates, but researchers found that even those who have this gene benefited from isothiocyanates: their lung cancer risk decreased 40 percent. And those who lack this gene had a 64 percent decreased lung cancer risk. This was presumably because the isothyocyanates remained in circulation longer in their bodies.

Here's some additional good news about broccoli: one of the isothiocyanates, known as sulforaphane, which protects your cells from carcinogens (cancer-causing agents), is particularly high in broccoli sprouts (grown from broccoli seeds). Researchers at Johns Hopkins University found that broccoli sprouts contain up to 50 times the concentration of these protective nutrients compared to mature broccoli plants.

Tasty broccoli sprouts can be readily added to sandwiches and salads. Although they're prohibitively expensive when purchased at the store, it's easy to sprout the seeds at home. A good sprouting kit and seeds can be purchased at www.sproutpeople.com.

Dr. Laurie Steelsmith is a naturopathic physician, licensed acupuncturist and author of "Natural Choices for Women's Health" (Random House, 2005). You can reach her and read her past columns at www.drsteelsmith.com. This column is for information only. Consult your health provider for medical advice.