The pendulum swings from fear to understanding
8. Philips LS, Langer RD. Postmenopausal hormone therapy: critical reappraisal and a unified hypothesis. Fertil Steril. 2005;83:558-566.
Soy versus placebo: Underwhelming
Georgina E. Hale, MD
Department of Obstetrics and Gynecology, University of Sydney, Sydney, Australia
RCT: Soy lacked effect on cognition, bone, and lipids
Thomas B. Clarkson, DVM
Professor of Comparative Medicine, Comparative Medicine Clinical Research Center, Wake Forest University School of Medicine, Winston-Salem, NC
Red clover, likewise
Trebs EE, Ensrud KE, MacDonald R, Wilt TJ. Phytoestrogens for treatment of menopausal symptoms: a systematic review. Obstet Gynecol. 2004;104:824–836. META-ANALYSIS
- Phytoestrogens did not significantly improve hot flashes, night sweats, and vaginal dryness, compared to placebo, in this meta-analysis of randomized, controlled clinical trials.
Data on 2,348 women (mean age, 53.1 years) experiencing a mean of 7.1 hot flashes per week were analyzed. Only randomized controlled trials reporting menopausal symptoms of hot flashes, night sweats, and vaginal dryness were included. Mean trial duration was 17 weeks.
- The 11 soy food or beverage supplementtrials (N = 995 women) found no improvement compared with placebo.
- Of the 8 soy food trialsreporting hot flash outcomes, only 1 showed a significant improvement compared with placebo.
- In the 9 soy extract trials, overall results (N = 854) were mixed. In 5 trials using soy extracts and reporting hot flash frequency, 3 found no significant difference in symptoms between the soy and placebo groups; the other 2 (total 114 subjects) found significant improvements.
- The 5 red clover trials(N = 400) showed no improvement over placebo.
Many women in these studies appear to have been perimenopausal rather than postmenopausal. Nine studies included women who had had a menstrual period within the previous 3 to 6 months (late perimenopausal). A subgroup analysis of perimenopausal women would have been useful, since their endocrinologic status is quite different from that of postmenopausal women.
Does soy improve cognition, bone density, or lipids?
Kreijkamp-Kaspers S, Kok L, Grobbee DE, et al. Effect of soy protein containing isoflavones on cognitive function, bone mineral density, and plasma lipids in postmenopausal women: a randomized controlled trial. JAMA. 2004;292:65–74. LEVEL 1 EVIDENCE: Randomized, controlled trial
- Soy did not benefit cognition, bone, or lipids in 60-to-75-year-old women.
This careful trial raises the question of how to reconcile these results with animal and observational studies. In all, 202 postmenopausal women aged 60 to 75 years received 25.6 g/day of a soy protein supplement containing 99 mg isoflavones or a milk protein powder for 1 year. Adherence was monitored by serum genistein. There were no notable differences in:
- Memory, verbal skills, or concentration.
- Bone mineral density or bone-specific alkaline phosphatase, calcium, or phosphorus levels.
- Cholesterol, triglycerides, and lipoprotein plasma levels. These findings may not relate to perimenopausal women, in whom soy has been seen to significantly reduce LDL, but only during midfollicular and periovulatory phases.1 Premenopausal2 but not postmenopausal3monkeys given soy have had beneficial effects on bone quality.
REFERENCES
1. Merz-Demlow BE, Duncan AM, Wangen KE, et al. Soy isoflavones improve plasma lipids in normocholes-terolemic, premenopausal women. Am J Clin Nutr. 2000;71:1462-1469.
2. Kaplan JR, et al. Supplementation reduces the trajectory of atherogenesis in premenopausal monkeys at high risk for development of extensive postmenopausal coronary artery plaques. Menopause. 2004;11:653. Abstract S-17.
3. Register TC, Jayo MJ, Anthony MS. Soy phytoestrogens do not prevent bone loss in postmenopausal monkeys. J Clin Endocrinol Metab. 2003;88:4362-4370.
LIFESTYLE THERAPYThe secret to keeping those girlish carotids
Wildman RP, Schott LL, Brockwell S, Kuller LH, Sutton-Tyrrell K. A dietary and exercise intervention slows menopause-associated progression of subclinical atherosclerosis as measured by intima-media thickness of the carotid arteries. J Am Coll Cardiol. 2004;44:579–585. LEVEL 1 EVIDENCE: Randomized, controlled trial
- Carotid artery intima media thickens during the transition through menopause, but diet and exercise can reduce this progression by almost 50%.
- A diet-and-exercise regimen staves off menopause-associated weight gain and increases in lipids, blood pressure, and blood glucose.
These important findings are strong evidence that diet and exercise can slow the subclinical atherosclerosis progression that accompanies the menopause transition.
The Women’s Healthy Lifestyle Project previously found that weight gain and increased lipids, glucose, and blood pressure often accompany the menopause transition.1 This report describes improvements with diet and exercise intervention, compared with controls.
A total of 535 women aged 44 to 50 years were randomized to lifestyle intervention or assessment-only. All were premenopausal, and all had normal to high-normal body mass index, diastolic blood pressure, and fasting glucose and cholesterol levels.
