Broccoli Helps Prevent Lung Cancer

A new study published in the Lancet suggests that the natural chemicals in broccoli, cabbage, bok choy, and other cruciferous vegetables may protect against lung cancer. Of 18,000 men studied, those with detectable isothiocyanates, a phytochemical, in their blood had a 36 percent lower chance of developing lung cancer than those with none.

Researchers warned the public not to depend on vegetables as infallible immunity against the strong cancer-causing effects of smoking or to rely on isothiocyanate supplements if they are ever produced. More than 20 different varieties of these compounds work intricately together in the body in ways that can't be duplicated in pill form. In fact, antioxidants taken in doses higher than that which occurs naturally in plant foods can actually increase cancer risk. The lesson, report investigators, is simple: "Just eat your vegetables, and lots of them."

Michuad DS, Feskanich D, Rimm EB, et al. Intake of specific carotenoids and risk of lung cancer in two prospective U.S. cohorts. Am J Clin Nutr 2000;72:990-7.

Dietary Fat Linked to Breast Cancer

In an effort to pinpoint the cause of breast cancer, British researchers have examined "all relevant epidemiological and biological evidence" pertaining to the disease's development. They found that dietary factors, especially fat, were strongly implicated. Researchers hypothesize that dietary fat does not cause the disease, but instead works to deplete essential agents normally able to fight it off.

While scientists scramble to identify what these nutrients are, there is no need to go unprotected. Plant foods have always triumphed in their disease-fighting ability. Protect yourself now with a rich variety of vegetables, fruits, grains, and legumes.

Wiseman R. Breast cancer hypothesis: a single cause for the majority of cases. J Epidemiol Community Health 2000;54:851-8.

Suspicious Mammograms Are Often False Alarms

Women at high risk for breast cancer are virtually guaranteed to receive a false-positive or "suspicious" mammography result at least once during ten years of routine screening, reveals a Boston University School of Public Health study, which found that cysts or swollen glands were often the cause for confusion. Researchers say the use of estrogen therapy, a lack of previous X-rays (to compare results), a family history of breast cancer, age factors, and varying levels of skill among radiologists can all increase a woman's risk of having an abnormal result.

If more women knew how common false-positive results are, there might be less stress and anxiety while waiting to undergo further diagnostic tests, which sometimes take weeks. Most importantly, greater educational initiatives focusing on the role of diet and lifestyle in breast cancer prevention would empower women to protect themselves rather than relying solely on early detection of the disease.

Christiansen CF, Wang L, Barton MB, et al. Predicting the cumulative risk of false-positive mammograms. J Natl Cancer Inst 2000;92:1657-66.

Esophageal and Gastric Cancer Prevention

Selenium, an essential nutrient found in grains, vegetables, and certain seeds and nuts, has proven itself as a powerful weapon in the fight against cancer. Researchers studied large groups of people in Linxian, China, a region with epidemic rates of esophageal and gastric cancers, and found that those who received selenium, beta-carotene, and vitamin E had significantly lower mortality rates than those who did not. They also found that selenium in the diet has the same effect. In fact, those with the highest levels of selenium in their blood developed cancers at about half the rate as those with the least.

There's no need to worry about taking selenium supplements. When you eat whole wheat bread with nut butter, enjoy fresh vegetables over pasta, or increase your intake of any whole grains or vegetables you like, you are adding potent cancer-fighters to your diet.

Mark SD, Qiao Y, Sanford DM, et al. Prospective study of serum selenium levels and incident esophageal and gastric cancers. J Natl Cancer Inst 2000;92:1753-63.

Fruits, Vegetables, and Lung Cancer

We know high-fiber, low-fat fruits and vegetables are essential to good health. A recent look at lung cancer incidence demonstrated how effectively they shield cells from possible danger. Researchers with the Netherlands Cohort Study followed 62,573 women and 58,279 men, aged 55 to 69, for more than six years, tracking the types and amounts of food eaten. The more fruits and vegetables the participants consumed, the lower their incidence of lung cancer. And it didn't seem to matter which kind, so if broccoli isn't your thing, have sweet potatoes, squash, or spinach burritos for dinner tonight, and throw some fresh blueberries on your breakfast cereal. The choices are endless.

Voorrips L, Goldbohm D, Verhoeven D, et al. Vegetable and fruit consumption and lung cancer risk in the Netherlands Cohort Study of Diet and Cancer, Cancer Causes, and Control. Cancer 2000;11:101-15.

Smoking Linked to Colon Cancer

The link between cigarette smoking and lung cancer is undeniable and well known. Now research has implicated the dangerous habit in the development of colon cancer as well. Two large prospective studies, including both men and women, found that smoking for 35 years was associated with higher colon cancer rates. Another study examined the type of tumors present in colon cancer patients and found that those who smoked were more likely to have microsatellite instability tumors (MSI), which contain unstable DNA.

"It provides support for the idea that lifestyle factors can cause tumor mutations," says University of Utah epidemiologist Martha Slattery. Researchers found the strongest links between tobacco use and MSI among people who smoked the longest and started at a young age.

Slattery ML, Curtin K, Anderson K, et al. Associations between cigarette smoking, lifestyle factors, and microsatellite instability in colon tumors. J Nat Cancer Inst 2000;92:1831-47.