Phytoestrogens May Reduce Risk of Lung Cancer
A new study at the University of Texas M.D. Anderson Cancer Center shows that natural compounds in beans and vegetables may reduce the risk of lung cancer. Phytoestrogens (phyto means plant) are structurally similar to estrogen hormones, but are much weaker. They occur naturally in many plants and, because they compete with the body’s natural estrogens to attach to estrogen receptors, they tend to reduce estrogen’s effects, thus reducing cancer risk. Researchers compared 1,674 lung cancer patients with 1,735 healthy individuals and concluded that those who consumed the most phytoestrogens had a 46 percent less chance of getting lung cancer. Previous studies have shown that phytoestrogens may also reduce the risk of cancers of the breast, uterus, and prostate.
Schabath MB, Hernandez LM, Wu X, Pillow PC, Spitz MR. Dietary phytoestrogens and lung cancer risk. JAMA. 2005;294:1493-1504.
Cancer Chemicals Reach Nonsmoking Housemates
Chemicals associated with lung cancer reach a five- to six-fold higher concentration in women who live with smokers than in those who live with nonsmokers. Researchers analyzed the urine of 23 nonsmoking women exposed to their husbands' cigarette smoke, finding elevated levels of compounds called NNAL and NNAL-Gluc, both metabolic products of NNK, a known carcinogen. The women showed higher levels of nicotine as well.
Previous studies have linked secondhand smoke and lung cancer. This study, appearing in the Journal of the National Cancer Institute, is the first to provide biochemical support of the observation.
Anderson KE, Carmella SG, Ye M, et al. Metabolites of a tobacco-specific lung carcinogen in nonsmoking women exposed to environmental tobacco smoke. J Natl Cancer Inst. 2001;93:378-81.
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.
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.
One More Reason to Quit
Women have a greater risk of developing smoking-related lung cancer, and the reason may be in their genes. A gene for the protein that encourages lung cancer is more active in women than men, say researchers, and nicotine increases the activity even further.
Researchers at the University of Pittsburgh studied lung tissue samples from men, women, and lung cancer patients and found higher levels of gene activity in women across the board—even for non-smokers. This means that women are likely to develop lung cancer after much less smoking and at a younger age.
Shriver SP, Bordeau HA, Gubish CJ et al. Sex-specific expression of gastrin-releasing peptide receptor: relationship to smoking history and risk of lung cancer. J Natl Cancer Inst 2000;92:24-33.
Women More Vulnerable to Cigarette Risks
Women may be more vulnerable than men to tobacco's cancer-causing effects. Dr. Natasha Buckshee of New York Presbyterian Hospital in New York City used computerized tomography (CT) to scan 1,000 long-term smokers over age 60 for signs of lung cancer. Cancer turned up in 10 men and 19 women. After adjusting for other risk factors, women smokers were shown to have a 2.3-fold higher risk of developing lung cancer than men. The findings were presented at the American College of Chest Physicians meeting in November.
So what pushes some people to smoke while others do not? A new study from the Centers for Disease Control and Prevention in Atlanta shows that adults who had multiple stressful events in childhood—emotional, physical, or sexual abuse, domestic violence, parental separation or divorce, or growing up with a substance-abusing, mentally ill, or imprisoned household member—were 5.4 times more likely to start smoking by 14 years of age and twice as likely to continue smoking as adults, compared to those with less traumatic childhoods, suggesting that tobacco serves as a treatment for anxiety, depression, or anger.
Anda RF, Croft JB, Felitti VJ, et al. Adverse childhood experiences and smoking during adolescence and adulthood. JAMA 1999;282:1652-8.