The Latest In . . .
Drugs ‘R Us
Hoffman-La Roche aims to make a killing from orlistat, a drug that blocks absorption of about 30 percent of the fat in foods. A new study in the Journal of the American Medical Association shows that obese volunteers taking the drug lost an average of 19 pounds, compared to a 13-pound weight loss in a placebo group. Perhaps they should market the placebo, because the safety of orlistat remains in doubt. A previous study found 12 cases of breast cancer among 1,063 women taking the drug, a finding not replicated in the new study.
Of course, a safer course would be to simply eat 30 percent less fat, particularly since diet drugs have proved dismal failures. However, the marketing of drugs is more aggressive now than ever. With sales shooting from $37.7 billion in 1990 to $78.9 billion in 1997, prescription drugs are the fastest growing portion of health-care costs. The number of sales representatives who promote drugs to physicians grew from 35,000 in 1994 to 56,000 in 1998—1 rep for every 11 doctors. A JAMA study last year reported that adverse drug reactions were the fourth leading cause of deaths in hospitals, killing 106,000 patients every year.
Drug use on farms is now blamed for the development of bacteria capable of resisting available antibiotics. In the U.S., untreatable fatal infections have begun to occur in hospitals. This year a strain of enterococci immune to all antibiotics turned up in Japan, having been identified in chickens imported from France, Vietnam, and Thailand.
Are there any good new drugs? Here’s one that may prove useful: Prometrium is an oral progesterone, derived from yams. Like Pro-Gest transdermal cream, Prometrium is an exact copy of human progesterone. In contrast, the older drug Provera has enough molecular differences from human progesterone to cause a wide range of adverse effects. Prometrium is manufactured by Solvay Pharmaceuticals. We suspect it will be tested for bone-building abilities and, if effective, may compete with Wyeth Ayerst’s aggressively marketed Premarin (conjugated estrogen), which is derived from horse urine and is linked to higher risk of breast cancer.
Davidson MH, Hauptman J, DiGirolamo M, et al. Weight control and risk factor reduction in obese subjects treated for 2 years with orlistat: a randomized controlled trial. JAMA. 1999;281:235-242.
ALTERNATIVES TO ANIMAL TESTING
New Tests for Ecotoxicity
The U.S. Geological Survey is now using a sophisticated nonanimal test to check for environmental dangers of chemical pollutants. Airborne and waterborne chemicals are collected with a synthetic membrane device that mimics the passage of chemicals through biological membranes. Using the Microtox Basic Test, the collected chemical is then applied to bacteria, Vibrio fisheri. The bacteria are naturally luminescent, and the chemical’s effect on their light-emitting system is a good index of ecotoxicity. A second test, Mutatox, checks for genetic damage to bacteria. The test is cheap, takes less than 24 hours to run, and requires no animals at all.
The test system was developed by B. Thomas Johnson of the Columbia Environmental Research Center, Columbia, Missouri.
Foods and Baldness
In Eat Right, Live Longer, PCRM president Neal Barnard proposed that foods may contribute to hair loss. Of course, hair loss is genetically determined, both for men and women, but foods may well affect how early in life it occurs. A new study supports this possibility. Harvard researchers found that men with the highest blood levels of a compound in the blood called insulin-like growth factor-1, are more likely to go bald. IGF-1 is found in milk, and earlier studies suggest that it passes into the human bloodstream of milk drinkers. Women with high insulin levels are also more likely to have male pattern baldness. High-fat, low-fiber diets interfere with insulin’s actions, forcing the body to make more and more insulin to compensate.
Signorello LB, Wuu J, Hsieh CC, Tzonou A, Trichopoulos D, Mantzoros CS, Hormones and hair patterning in men: a role for insulin-like growth factor 1? J Am Acad Dermatol. 1999;40:200-203.
Fiber and Colon Cancer
News reports in January announced that fiber may not protect against colon cancer after all, based on an article in the New England Journal of Medicine. For those left totally confused by the finding, here’s what actually happened:
In the Harvard Nurses’ Health Study, 88,757 women filled out diet questionnaires in 1980 and were followed for the next 16 years. Comparing those who had the most fiber in their diets (about 25 grams per day) to those with the least (about 10 grams per day), the higher-fiber group had 11 percent fewer cases of colorectal cancer diagnosed in the 16-year follow-up period, compared to those with the least fiber. The problem was that this difference was small enough that it could easily have resulted from chance; hence, the news reports saying they could not find a protective effect of fiber.
The most important conclusion from the study is that small changes in the diet probably make little difference. Many health-conscious people who have not yet eliminated meat, dairy products, and fried foods from their diets have hoped that a little extra fiber or some fruits and vegetables might help. But in the context of a typical American diet, 25 grams of fiber could not be expected to do much. On the other hand, vegetarians have roughly half the cancer risk of meat-eaters.
The Effect of Calcium
A second report from the New England Journal of Medicine showed that calcium may reduce the risk of colon polyps, which are often precursors to cancer. The reduction in polyps was modest, and the study used calcium supplements, 1,200 milligrams per day, not dairy products. Researchers now take pains to point out the difference between calcium supplements, which do show benefits in clinical studies, and dairy products, which often do not. University of South Carolina researchers reported in the January 1999 American Journal of Epidemiology that calcium supplements may protect against heart attacks, but that milk products do not appear to offer this benefit.
Baron JA, Beach M, Mandel JS, et al. Calcium supplements for the prevention of colorectal adenomas. N Engl J Med. 1999;340:101-107.
Fuchs CS, Giovannucci EL, Colditz GA, et al. Dietary fiber and the risk of colorectal cancer and adenoma in women. N Engl J Med. 1999;340:169-176.
Thorogood M, Mann J, Appleby P, McPherson K. Risk of death from cancer and ischaemic heart disease in meat and non-meat eaters. Brit Med J. 1994;308:1667-1670.
Feskanich D, Willett WC, Stampfer MJ, Colditz GA. Milk, dietary calcium, and bone fractures in women: a 12-year prospective study. Am J Publ Health. 1997;87:992-997.
Treating Attention Deficit Disorders with Food
The National Institutes of Health report that nutritional treatments may be effective for attention-deficit hyperactivity disorder. The report, drafted by L. Eugene Arnold of Ohio State University, showed that elimination diets appear effective, based on eight clinical trials. In addition, essential fatty acids, glyconutritionals, magnesium, Chinese herbal preparations, and other supplements also hold promise.
Controversy over the role of diet in hyperactivity began in 1975 when Ben Feingold proposed that dietary factors—especially artificial colors, flavors, and preservatives—could affect children’s behavior. The hypothesis failed in initial research studies, but with more aggressive diet changes the treatment has proven effective.
Breastfeeding: The More, the Better
Breastfeeding helps babies resist infections. But what about part-time breastfeeding? Benefits are seen for babies receiving most of their nutrition from mother’s breast for at least six months, but babies who get less than half their nutrition from breast milk have as many infections as those who get no breast milk at all. This finding comes from data on 7,000 infants, analyzed by Jeanne Raisler of the University of Michigan School of Nursing.