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Mice Are Not Men…Or Women
Much of what government regulators thought they knew about the health effects of industrial chemicals, such as PCBs, came from rodent experiments and is now being contradicted by a new human study. Researchers at the University of California found that many PCBs block steroid and xenobiotic receptors in humans rather than activate them, as tests on rats had suggested. PCBs were banned in 1976 in the United States due to their toxicity, but still persist in the soil, air, and water. They accumulate in the livers of animals, causing brain damage, cancer, and other problems.
Tabb MM, Kholodovych V, Grun F, Zhou C, Welsh WJ, Blumberg B. Highly chlorinated PCBs inhibit the human xenobiotic response mediated by the steroid and xenobiotic receptor (SXR). Environ Health Perspect. 2004;112:163-169.
Clinical researchers routinely alter the results of their studies to present the outcomes they desire, according to a study from Oxford University. A research team reviewed the results of more than 100 scientific trials and discovered that “inconvenient” findings were often not reported to the public. In half of the cases, the stated purpose of the trial was altered as it progressed so that acceptable findings could be published. The same percentage omitted crucial information about the effectiveness of a certain treatment or potential harmful effects.
Chan AW, Hrobjartsson A, Haahr MT, Gotzsche PC, Altman DG. Empirical evidence for selective reporting of outcomes in randomized trials: comparison of protocols to published articles. JAMA. 2004;291:2457-2465.
Eating Fish Exposes Babies to Mercury
The EPA estimates that mercury exposures in the womb may put more than 600,000 babies each year at risk for birth defects or learning disabilities. The findings, which are nearly double previous estimates, stem from a new understanding that umbilical cord blood has 1.7 times more mercury than mother’s blood. One in six U.S. women of childbearing age has enough mercury in her blood to affect her child, the main sources of exposure being tuna, swordfish, shark, and other large fish.
Kaiser Family Foundation Report, February 2004.
Good Carbs Great for Weight Loss
After 12 weeks on a high-carbohydrate eating plan, both men and women lost more weight and body fat than a control group consuming a similar number of calories from fattier foods. According to research from the Archives of Internal Medicine, participants lost about 7 pounds by consuming low-fat, high-carb foods for 12 weeks with no restriction on portion sizes. Adding moderate exercise increased the loss to 11 pounds. Similar to past research, the study demonstrates that low-fat, complex carbohydrate-rich foods are excellent for facilitating weight loss.
Hays NP, Starling RD, Liu X, et al. Effects of an ad libitum low-fat, high-carbohydrate diet on body weight, body composition, and fat distribution in older men and women. Arch Intern Med. 2004;164:210-217.
Fiber-Rich Diet Lowers Heart Disease Risk
Dietary fiber from cereal and fruit lowers risk for coronary heart disease in men and women, according to a report in the Archives of Internal Medicine. Researchers analyzed data from ten studies involving more than 90,000 men and more than 240,000 women in the United States and Europe, finding that every 10 grams of fiber in the daily diet is associated with a 14 percent reduction for all coronary events and a 27 percent reduction in coronary deaths.
In a second study, adults consuming the most dietary fiber had the lowest serum concentrations of C-reactive protein (CRP), a marker of inflammation that may predict future cardiovascular events, according to a study including 4,000 men and women over 20 years of age. Fiber is found in beans, vegetables, fruits, and whole grains and is not found in animal-derived products.
Pereira MA, O’Reilly E, Augustsson K, et al. Dietary fiber and risk of coronary heart disease. Arch Intern Med. 2004;164:370-376.
Ajani UA, Ford ES, Mokdad AH. Dietary fiber and c-reactive protein: finding from National Health and Nutrition Examination Survey data. J Nutr. 2004;134:1181-1185.
Soymilk Lowers “Bad” Cholesterol
Soymilk cuts cholesterol, according to researchers in Sao Paulo, Brazil. The research team put 60 outpatients, ages 20 to 70, on a cholesterol-lowering diet for six weeks. They then added either soymilk or non-fat cow’s milk to the diet for six weeks. Subsequently, the treatments were switched: those drinking soymilk consumed non-fat cow’s milk and vice versa. In the soymilk group, low-density lipoprotein (“bad”) cholesterol fell 9 mg/dl, whereas the dairy group’s “bad” cholesterol increased 1 mg/dl. The soymilk group’s high-density lipoprotein (“good”) cholesterol increased 4 mg/dl, whereas the nonfat dairy group’s “good” cholesterol decreased 1 mg/dl.
Bricarello LP, Kasinski N, Bertolami, MC, et al. Comparison between the effects of soymilk and non-fat cow milk on lipid profile and lipid peroxidation in patients with primary hypercholesterolemia.
Hormones Linked to Stroke and Blood Clots
Premarin increases the risk of stroke and dangerous blood clots in postmenopausal women, findings that have caused another portion of the long-running Women’s Health Initiative (WHI) to be terminated early. As reported in the Journal of the American Medical Association, the study was conducted in 40 U.S. cities beginning in 1993, including more than 10,000 women, 50 to 79 years of age, who had undergone a hysterectomy. Previous WHI findings found that hormones do not protect women from heart disease as doctors once believed and actually increase heart disease and cancer risk.
Anderson GL, Limacher M, Assaf AR, et al. Effects of conjugated equine estrogen in postmenopausal women with hysterectomy: the Women’s Health Initiative randomized controlled trial. JAMA. 2004;291:1701-1712.