Obesity, Diet Linked to Deadly Cancers
Raloff, Janet, Science News
Esophageal cancer usually kills its victims within 6 months of diagnosis. Since the early 1970s, the incidence of one form of this malignancy has tripled among white men, the group at highest risk in the United States. A new study now suggests that obesity may foster this form of the cancer, while diets high in fiber and fresh produce seem to offer comparable protection against it.
Another study finds that produce and olive oil may help protect against breast cancer, the second leading cause of cancer deaths in U.S. women.
Linda Morris Brown of the National Cancer Institute in Bethesda, Md., led a four-state team of researchers who used questionnaires on diet and medical history to hunt for esophageal cancer risks in men.
Two malignancies predominate in the esophagus -- the digestive tract between the pharynx and the entrance to the stomach. Squamous cell carcinoma, which preferentially strikes blacks, develops high in the esophagus. In contrast, Brown's team found, adenocarcinoma -- which usually develops lower in the esophagus -- tends to claim heavy victims.
To the researchers' surprise, the new study turned up 184 cases of adenocarcinoma -- 174 of them in white men. The researchers compared their data on these white men with information on 750 cancerfree white men matched by age. In the Jan. 18 Journal of the National Cancer Institute (JNCI), Brown's team reports that the heaviest 25 percent of the men in the study had more than three times the cancer risk of the thinnest quarter.
How heavy was the top quartile? Based on a weight-to-size ratio, a 6-foot man needed to weigh about 215 pounds to qualify. Upon further investigation, Brown and her coworkers found that the most obese men in that quartile faced almost four times the cancer risk of men in the thinnest quartile. …