CRD summary

This review assessed non-prescription supplements for menopausal symptoms, particularly hot flushes. The authors concluded that the limited evidence about red clover, soy, sage and black cohosh suggests that more research is required. Given the limitations of the review and the paucity of evidence for some interventions, the authors' conservative conclusions and suggestions for further research seem appropriate.

Authors' objectives

To evaluate non-prescription supplements (NPS) for the treatment of menopausal symptoms, in particular hot flushes.

Searching

MEDLINE, ProQuest and the Cochrane CENTRAL Register were searched from 1940 to March 2004 using the reported keywords.

Study selection

Assessment of study quality

The authors did not report any formal assessment of validity. However, aspects of methodological quality such as the adequacy of the sample size, blinding and drop-outs were noted in the text and tables.

Data extraction

The authors did not state how the data were extracted for the review, or how many reviewers performed the data extraction. For each study, The proportional change from baseline or difference compared with control treatments was extracted with relevant levels of statistical significance.

Methods of synthesis

Results of the review

Twenty-four studies were included in the review: 21 RCTs (n=2,175), 1 CCT (n=60) and 2 uncontrolled trials (n=86).

Effectiveness.

Black cohosh (4 RCTs, n=352; 1 CCT, n=60; 2 uncontrolled trials, n=86): all 7 studies reported a significant improvement in menopausal symptoms after 12 to 24 weeks compared with placebo. One RCT reported no significant difference between treatments in the frequency of hot flushes.

Red clover (4 RCTs, n=370): 1 RCT reported a significant reduction in the frequency of hot flushes compared with placebo; the other three reported no significant difference between red clover and placebo.

Soy isoflavonoids (9 RCTs, n=912): 5 RCTs reported a significant reduction in the frequency of hot flushes compared with placebo; the other four reported no significant difference between soy isoflavonoids and placebo.

Sage plus alfalfa (1 RCT, n=30): the RCT reported a significantly greater reduction in the frequency of hot flushes at 12 weeks compared with placebo.

Studies reported no significant difference in hot flushes between dong quai (1 RCT, n=71), evening primrose oil (1 RCT, n=56) or ginseng (1 RCT, n=384) versus placebo.

Safety.

The most common adverse effects reported were gastrointestinal (bloating, nausea and constipation). Studies reported no significant difference in adverse effects between placebo and black cohosh, dong quai, evening primrose oil, red clover, sage and soy (no details were reported). Adverse effects reported in studies not included in the efficacy review were also presented, but not in detail.

Authors' conclusions

Limited evidence about the effects of red clover, soy, sage and black cohosh on hot flushes in menopausal women suggests that more research is required. There was no support for treating hot flushes with dong quai, evening primrose oil or ginseng.

CRD commentary

The review addressed a clear question that was defined in terms of the participants, intervention and study design. The authors undertook a limited search and it was unclear whether any language restrictions had been applied, therefore publication and language bias cannot be ruled out. The methods used to select studies and extract the data were not described, so it is not known whether any efforts were made to reduce reviewer errors and bias. The reviewers did not state that they formally assessed validity, but some relevant aspects of study quality were discussed in the text.

The narrative synthesis was appropriate given the differences between the studies, and the synthesis took some aspects of study quality into account. Potential reasons for differences between the studies were discussed, particularly with respect to the adequacy of the sample size. Given the limitations of the review, the lack of a systematic assessment of validity, and the paucity of evidence for some interventions, the authors' conservative conclusions and the suggestions for further research seem appropriate.

Implications of the review for practice and research

Practice: The authors stated that women who have clotting disorders or are taking anticoagulants should not take dong quai, although evidence relating to this was not evaluated in the review.

Research: The authors stated that there is a need for further appropriately designed, adequately powered studies to evaluate the efficacy and long-term safety of red clover, soy, sage and black cohosh for the treatment of menopausal flushes. Studies evaluating isoflavonoids should ensure that women in placebo groups do not inadvertently consume isoflavonoids. Research is also required to evaluate the influence of basal metabolic index and adiposity on the responses of individual women to isoflavonoids.

Bibliographic details

Hanna K, Day A, O'Neill S, Patterson C, Lyons-Wall P. Does scientific evidence support the use of non-prescription supplements for treatment of acute menopausal symptoms such as hot flushes? Nutrition and Dietetics 2005; 62(4): 138-151.

Indexing Status

Subject indexing assigned by CRD

MeSH

Angelica sinensis; Cimicifuga; Dietary Supplements; Drugs, Chinese Herbal /therapeutic use; Estrogens, Non-Steroidal; Fatty Acids, Essential; Female; Hot Flashes /prevention & control; Isoflavones; Medicine, Chinese Traditional; Menopause; Middle Aged; Panax /therapeutic use; Phytoestrogens; Phytotherapy; Plant Extracts /therapeutic use; Plant Oils /therapeutic use; Plant Preparations /therapeutic use; Plants, Medicinal; Salvia officinalis; Soybeans; Sweating; Trifolium

AccessionNumber

12006005178

Database entry date

31/07/2007

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.