AltmedWatch

ALTMED WATCH
The latest research on complementary and alternative medicine

Soy isoflavones and bone loss

Soy isoflavones may reduce spinal bone loss in perimenopausal women, according to a recent randomized, double-blind study. To reach that conclusion, investigators fed either isoflavone-rich soy (80 mg/day of isoflavone), isoflavone-poor soy (4.4 mg/day), or whey to about 70 women over 6 months. After doing multiple regression analyses to take into account confounding factors, the researchers found that a high isoflavone diet had a significant positive effect on the bone mineral density and bone mineral content of the lumbar spine.¹

These results corroborate the findings of a similar trial that found 40 g of soy protein containing 90 mg/day of isoflavones, also given for 6 months, had a beneficial effect on the lumbar spine—but not on other bone sites.²

An editorial accompanying the newest trial cautions, however, that 6-month studies are really too short to assess the effects of soy on a clinical outcome like fracture rate because the bone remodeling cycle typically takes up to 80 weeks.³ Despite this precaution, the data are consistent with the hypothesis that soy isoflavones have an estrogenic effect on bone.

1. Alekel DL, St Germain A, Peterson CT, et al. Isoflavone-rich soy protein isolate attenuates bone loss in the lumbar spine of perimenopausal women. Am J Clin Nutr. 2000;72:844-852.

2. Potter SM, Baum JA, Teng H, et al. Soy protein and isoflavones: their effects on blood lipids and bone density in postmenopausal women. Am J Clin Nutr. 1998;68(Suppl):1375S-1379S.

3. Erdman JW, Stillman RJ, Boileau RA. Provocative relation between soy and bone maintenance. Am J Clin Nutr. 2000;72:679-680.

Smoking addiction doesn't respond to hypnosis

Hypnotherapy does not seem to be an effective approach to smoking cessation, according to a recent Cochrane Library review of the literature. Several types of clinical trials were evaluated to arrive at this conclusion: The studies that compared hypnotherapy to no treatment contradicted one other, often arriving at opposite conclusions on the efficacy of hypnosis. In the clinical investigations that compared patients on hypnosis to those receiving counseling, a health education lecture, and other interventions, two were positive and two negative. Likewise, those studies that compared hypnosis to group therapy or rapid/focused smoking were disappointing.

Abbot NC, Stead LF, White AR, et al. Hypnotherapy for smoking cessation. The Cochrane Database Syst Rev. 2000;(2):CD001008.

Acupuncture may benefit cocaine addicts

Cocaine-dependent patients may respond to acupuncture, suggests this small, randomized, placebo-controlled study. Over a period of 8 weeks, researchers from Yale University School of Medicine divided patients into three groups, inserting four needles into the ears at traditionally used acupuncture points in one group and at "nontherapeutic" points in a second group. The third group was shown relaxation videos.

Those in the active acupuncture group were more than three times as likely to have cocaine-negative urine samples than those viewing the tapes and about 2.5 times as likely to be urine-negative as those receiving sham acupuncture.

Avants SK, Margolin A, Holford TR, et al. A randomized, controlled trial of auricular acupuncture for cocaine dependence. Arch Intern Med. 2000;160:2305-2312.

Fish oil, CAD risk, and postmenopausal women

Fish oil concentrate can lower serum triglycerides and the triglyceride:HDL ratio among postmenopausal women who are and are not on HRT, according to this clinical trial. Giving fish oil supplements rich in eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA) or a placebo to 36 volunteers, Canadian investigators found that the supplements caused a 26% greater decline in serum triglyceride levels and a 28% greater decrease in the triglyceride:HDL ratio. Extrapolating to the population as a whole, the researchers estimate that 2.4 g of EPA and 1.6 g of DHA could reduce the risk of coronary artery disease by 27% in postmenopausal women.¹

While many experts would not recommend consuming such large doses of EPA and DHA, the American Heart Association has just published new guidelines that encourage greater intake of these fatty acids from food. The 2000 revision of the American Heart Association Dietary Guidelines recommends that all healthy Americans "eat at least two servings of fish per week."² The Association cites an extensive list of studies that support the belief that these omega-3 fatty acids may reduce the risk of sudden cardiac death, decrease the risk of arrhythmia, lower serum triglycerides, and reduce blood clotting tendency.

1. Starck KD, Park EJ, Maines VA, et al. Effect of a fish oil concentrate on serum lipids in postmenopausal women receiving and not receiving hormone replacement therapy in a placebo-controlled, double-blind trial. Am J Clin Nutr. 2000;72:389-394.

2. Krauss RM, Eckel RH, Howard B et al. AHA Dietary Guidelines Revision 2000: a statement for healthcare professionals from the Nutrition Committee of the American Heart Association. Circulation. 2000;102:2296-2311.

A second look at preeclampsia and calcium supplements

Although a major 1997 clinical trial concluded that calcium supplements do not prevent preeclampsia, mounting evidence since then strongly suggests that the mineral can play an important role in thwarting the disorder.

In 1997, the CPEP (Calcium for Preeclampsia Prevention) study found that "calcium supplementation during pregnancy did not prevent preeclampsia, pregnancy-associated hypertension, or adverse perinatal outcomes in healthy nulliparous women."¹ However, two recent systematic reviews of controlled trials, including CPEP, have taken a closer look at the various subpopulations of pregnant women and found a strong beneficial effect of calcium in healthy high-risk women or those with a low initial intake of dietary calcium.^2,3 In one meta-analysis, women who responded to supplementation were previously identified as being at high risk for preeclampsia by a positive rollover test or a positive test followed by a positive angiotensin sensitivity test. (Women had a positive rollover test if their diastolic pressure jumped by at least 20 mm Hg when they were turned from the left-lateral recumbent to the supine position.) The researchers estimated that the relative risk of the disorder for women on calcium was about a fifth of what it normally would have been if they hadn't taken supplements (RR = 0.19).

In the second review, published by the Cochrane Library, it was concluded that calcium supplements (1 to 2 g of elemental calcium a day) reduced the risk of pregnancy-related hypertension by about 50% among women with a low baseline calcium intake, estimated to be less than a mean of 900 mg a day (RR= 0.49). Similarly, the RR of preeclampsia was 0.32 amongst women in this subgroup.

It is possible that the CPEP trial failed to detect a beneficial effect of calcium for two reasons: (1) It didn't separate high- and low-risk candidates; and (2) Women in both arms of the trial received prenatal vitamins containing significant amounts of vitamin D (400 IU), which is essential for the intestinal absorption of calcium. That much vitamin D may have mitigated the detrimental effects of a calcium deficiency on smooth-muscle contractility in uterine blood-vessel walls.

1. Levine RJ, Hauth JC, Curet LB, et al. Trial of calcium to prevent preeclampsia. N Engl J Med. 1997;337:69-76.

2. DerSimonian R, Levine RJ. Resolving discrepancies between a meta-analysis and a subsequent large controlled trial. JAMA. 1999;282:664-670.

3. Atallah AN, Hofmeyr GJ, Duley L. Calcium supplementation during pregnancy for preventing hypertensive disorders and related problems. Cochrane Database Syst Rev. 2000;(2):CD001059.

Ginseng may lower blood glucose

Panax quinquefolius, better known to the public as American ginseng, may attenuate postprandial glycemia, suggests this small, placebo-based experiment. When patients with Type 2 diabetes were given 3 g of the herb or a placebo 40 minutes before or during a 25-g glucose load, those on the herb experienced a significantly greater drop in blood glucose at both time intervals. Based on these results, the researchers speculate that the herb may have value as an adjunct to diet and medication for Type 2 diabetes but caution that larger, long-term trials are needed to confirm that hypothesis.

On the downside, however, if a well-controlled diabetic begins taking the herb without informing her physician, it may result in unexplained fluctuations in blood glucose readings.

Vuksan V, Sievenpiper JL, Koo, VY, et al. American ginseng (Panax quinquefolius L) reduces postprandial glycemia in nondiabetic subjects and subjects with type 2 diabetes mellitus. Arch Intern Med. 2000;160:1009-1013.

Department editor Paul L. Cerrato, MA, Managing Editor of Contemporary OB/GYN, is a guest lecturer at the Institute of Human Nutrition, Columbia University College of Physicians and Surgeons, New York, N.Y.

Paul Cerrato. AltmedWatch.

Contemporary Ob/Gyn

2000;11:144, 150.