Health & Medicine
Health Watch: Keep Fat Down, Cancer at Bay
Ever since studies began showing that Japanese women are less likely than American women to have breast cancer, scientists have been trying to link diet and cancer risk. Last week, a study presented at the American Society of Clinical Oncology's annual meeting gave them a glimmer of success. Researchers found that eating a low-fat diet could decrease the risk of breast cancer recurrence. They counseled 975 women who had been treated for early-stage breast cancer on how to lower dietary fat. An additional 1,462 women ate their usual diet. After about five years, only 9.8 percent of the women who ate less fat had a recurrence of breast cancer, compared with 12.4 percent of the women who ate their normal diet. The diet worked best for women whose tumors were not sensitive to estrogen.
The reduction is enough for doctors to suggest that women with breast cancer eat less fat, says author Rowan Chlebowski of the Los Angeles Biomedical Research Institute. But the evidence isn't strong enough to make anyone feel guilty about every burger or cupcake.
Still, don't jump into the fat-free-cookie craze again. Unsaturated fats like olive oil are healthful. "Just reducing fat intake means people will be eating a lot more carbohydrates," warns Walter Willett, chair of the department of nutrition at the Harvard School of Public Health. And that can increase the risk of diabetes and heart disease.
Health Watch: Not Another Shot--I Promise
In 2004, almost 20,000 Americans--many of them teenagers--got pertussis, a disease marked by such severe coughing spasms that it sounds like whooping. That's a huge backslide from 1976, when only about 1,000 people contracted the highly contagious bacterial infection. Traditionally kids receive their last vaccination for pertussis at age 7, while getting a booster for diphtheria and tetanus at age 11. Since some childhood vaccinations become less effective after five to 10 years, "among adolescents the immunity to pertussis has waned," says David Neumann, executive director of the National Partnership for Immunization. Now a beefed-up vaccine, called Boostrix, is available for kids 10 to 18. Taking a one-shot approach, a pertussis vaccine will be added to the diphtheria and tetanus booster. Fewer grown-ups get whooping cough, but "pertussis boosters for adults are also being developed," says Neumann.
Health Watch: It's All in Your Head, Honey
While they're fodder for jokes about women's behavior during that "time of the month," premenstrual irritability and mood swings affect nearly 75 percent of menstruating women. An estimated 3 to 9 percent of women experience severe mood swings and physical symptoms, a condition known as premenstrual dysphoric disorder, or PMDD. No one knows why some women are predisposed to this condition. Now research being published this month in the online journal Nature Neuroscience says brain receptors called GABAA receptors actually change in the hippocampus during the ovarian cycle. Researchers stressed female mice and monitored their brain activity with an EEG. Then they examined cross sections of the mice's brains and found that the GABAA receptors had become less able to inhibit stress responses. That could explain the increased anxiety often associated with PMDD. "We finally found a part of the brain that hormones actually change during the cycle," says University of California-Los Angeles professor of neurology Istvan Mody. "If that is the case, then we can develop drugs that home in on some of these specific targets."
This story appears in the May 30, 2005 print edition of U.S. News & World Report.
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