Altmed Watch

ALTMED WATCH
The latest research on complementary and alternative medicine

How safe are plant estrogens?

While experts continue to debate the effects of herbal remedies on menopausal symptoms, some are asking if their purported estrogenic effects may increase the risk of estrogen-dependent cancers. At least one recent double-blind clinical trial suggests they do not.

When approximately 150 peri- and postmenopausal women were put on either 39 mg (the standard dose) or 127.3 mg of black cohosh extract (Remifemin) for 24 weeks, investigators detected no changes in vaginal cytology to suggest the herb stimulates tissue growth. Likewise, there were no significant changes in serum estradiol, luteinizing hormone, follicle-stimulating hormone, prolactin, or sex hormone-binding globulin.

Liske E, Hanggi W, Henneicke-Von Zepelin H, et al. Physiological investigation of a unique extract of black cohosh (Cimicifugae racemosae rhizoma): a 6-month clinical study demonstrates no systemic estrogenic effect. J Women's Health Gend-Based Med. 2002;11:163-174.

The effect of flaxseed on serum lipids

Flaxseed supplements can improve serum lipids in postmenopausal women, suggests this small, double-blind randomized study. In a trial that compared 40 g of ground flaxseed, a rich source of phytoestrogens called lignins, to a control regimen based on wheat over a 3-month period, the former significantly lowered total serum cholesterol and non-HDL levels (total cholesterol minus HDL). Likewise flaxseed reduced serum apolipoprotein A1 and B levels, by 6% and 7.5% respectively (P< 0.005). The supplement did not, however, affect biomarkers for bone metabolism.

Lucas EA, Wild RD, Hammond LJ, et al. Flaxseed improves lipid profile without altering biomarkers of bone metabolism in postmenopausal women. J Clin Endocrinol Metab. 2002;87:1527-1532.

Replacing epidurals with acupuncture

Acupuncture can significantly reduce the need for epidural analgesia during labor. That's the conclusion suggested by this randomized nonblinded Swedish investigation of 90 healthy pregnant women.

Acupuncture reduced the need for analgesia (12% vs. 22% in controls. RR, 0.52, 95% CI 0.3–0.9). It also produced a greater degree of relaxation, causing researchers to wonder whether its effect during labor was analgesic or relaxing. All participants in the trial had a normal singleton pregnancy, spontaneous onset of labor beyond 37 weeks' gestation, cephalic presentation, and cervical dilation at or below 6 cm at admission.

Ramnero A, Hanson U, Kihlgren M. Acupuncture treatment during labour—a randomized controlled trial. Br J Obstet Gynaecol. 2002;109:637-644.

Can exercise help fibromyalgia patients?

Apparently so. When 132 patients suffering from this perplexing musculoskeletal disorder were randomly assigned to either graded aerobic exercise or relaxation and flexibility exercises (the control group), significantly more patients in the aerobics group rated themselves as much or very much better after 3 months (35% vs. 18%, P=0.03). Those benefits were sustained or actually grew at 1 year follow-up. Subjects in the aerobics group also reported fewer tender points (4.2 vs. 2.0, P=0.02).

Patients met in hour-long classes twice a week, and most were prescribed walking on a treadmill and cycling on an exercise bike. With the help of personal trainers, patients were encouraged to gradually increase the amount of exercise they did. Initially they participated in two sessions of exercise per class, each lasting 6 minutes. At the end of 3 months, they were up to 25 minutes per session.

Richards SC, Scott DL. Prescribed exercise in people with fibromyalgia: parallel group randomized controlled trial. Br Med J. 2002;325:185.

Tea consumption may benefit heart and bone

Regularly drinking black tea may reduce a person's risk of myocardial infarction by 43%, compared to nondrinkers, and may even reduce the threat of a fatal coronary event by 70%. That's the implication of the Rotterdam study, a Dutch investigation that found the protective effect of tea (>375 mL/day), was even greater in women than men.

A similar epidemiologic survey done in Taiwan found that persons who had been habitually drinking either green, black, or oolong tea for 6 to 10 years had significantly higher lumbar spine bone mineral density (BMD), compared to persons who were not habitual tea drinkers. Those who were drinking tea for more than 10 years had the highest BMDs at all measured sites. Researchers theorize that the flavonoids in tea may be partially responsible for its apparent beneficial effects on heart and bone. In vitro and animal research has shown that certain flavonoids have a mild estrogenic effect.

Geleijnse JM, Launer LJ, van der Kuip DA, et al. Inverse association of tea and flavonoid intakes with incident myocardial infarction: the Rodderdam Study. Am J Clin Nutr. 2002;75:880-886.

Wu CH, Yang YC, Yao WJ, et al. Epidemiological evidence of increased bone mineral density in habitual tea drinkers. Arch Intern Med. 2002;162:1001-1006.

Poor memory? Forget about ginkgo

While there's evidence to show that ginkgo biloba may improve memory among cognitively impaired elderly patients with cerebrovascular disease or Alzheimer's, a recent controlled trial has found that, over the short term, it does not have any significant effects on normal older adults.

After putting volunteers on placebo or 40 mg t.i.d. of the herb for 6 weeks, researchers were unable to detect any improvements on standardized neuropsychological tests that measure verbal and non-verbal learning, memory, or concentration.

Solomon PR, Adams F, Silver A, et al. Ginkgo for memory enhancement. JAMA. 2002;288:835-840.

Le Bars PL, Katz MM, Berman N, et al. A placebo-controlled, double-blind, randomized trial of an extract of Ginkgo biloba for dementia. JAMA. 1997;278:1327-1332.

Can a microbe-infested environment protect against asthma?

Exposure to a "dirty" environment at a very young age can decrease the risk of hay fever, atopic asthma, and similar disorders by "priming the immune pump," suggests this recent New England Journal of Medicine report.¹ European investigators have found that children who had been exposed to relatively high levels of bacterial endotoxin—mostly from living on farms—had less production of inflammatory cytokines in peripheral leukocytes, signaling a marked down-regulation of their immune response. That attenuated immune response in turn was linked to less allergic disease.

Researchers theorized that exposure to microorganisms during maturation of a child's immune system may help the child develop tolerance to other components of his natural environment, including potential allergens. Support for this so-called hygiene hypothesis comes from other epidemiological studies and several animal experiments. Children are less likely to develop atopy, for instance, if they have attended day-care centers in early childhood.² The use of antibiotics—which obviously reduces one's exposure to bacterial endotoxin—during the first year of life has been correlated with an increased risk of asthma and other related diseases in those genetically predisposed to atopy.³ And in animal studies, treatment with mycobacteria protects against allergic encephalomyelitis, while administration of other microorganisms has been shown to reduce airway hyperresponsiveness in bronchial asthma.⁴

While the immediate clinical implications of this research are a little vague, two recent clinical trials have found that probiotic supplements like Lactobacillus GG can prevent atopic dermatitis.^5,6

REFERENCES

1. Braun-Fahrlander C, Rieder, J, Herz U, et al. Environmental exposure to endotoxin and its relation to asthma in school-age children. N Engl J Med. 2002;347:869-877.

2. Kramer U, Heinrich J, Wjst M, et al. Age of entry to day nursery and allergy in later childhood. Lancet. 1999;353:450-454.

3. Droste JH, Wieringa MH, Weyler JJ, et al. Does the use of antibiotics in early childhood increase the risk of asthma and allergic disease? Clin Exp Allergy. 2000;30:1547-1553.

4. Bach JF. The effect of infections on susceptibility to autoimmune and allergic diseases. N Engl J Med. 2002;347:911-920.

5. Kalliomaki M, Salminen S, Arvilommi H, et al. Probiotics in primary prevention of atopic disease: a randomized placebo-controlled trial. Lancet. 2001;357:1076-1079.

6. Isolauri E, Arvola T, Sutas Y, et al. Probiotics in the management of atopic eczema. Clin Exp Allergy. 2000;30:1604-1610.

A whole-grain regimen may thwart type 2 diabetes

A diet rich in whole-grain cereals and breads significantly improves insulin sensitivity in overweight, hyperinsulinemic adults, and may therefore reduce the risk of type 2 diabetes. The randomized clinical trial that arrived at that conclusion required insulin-resistant subjects to consume their regular refined grain diet for 6 weeks and then to be switched to the whole-grain regimen for 6 weeks.

Fasting insulin levels dropped by 10% on the whole-grain diet, results that are consistent with at least four observational studies that have found an inverse association between cereal fiber or whole grains and type 2 diabetes.

Pereira MA, Jacobs DR, Pins JJ, et al. Effect of whole grains on insulin sensitivity in overweight hyperinsulinemic adults. Am J Clin Nutr. 2002;75:848-855.

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.

 

altmed january. Contemporary Ob/Gyn 2003;1:101-102.