This summary table contains detailed information about research studies. Summary tables offer an informative look at the science behind many breast cancer guidelines and recommendations. However, they should be viewed with some caution. In order to read and interpret research tables successfully, it is important to understand some key concepts. Learn how to read a research table.
|
Introduction: Although postmenopausal hormones containing estrogen and progestin may ease menopausal symptoms, long-term use increases the risk of breast cancer (see Table 8) [1]. For this reason, many women seek other ways to reduce hot flashes and other symptoms.
Dietary and herbal supplements have been suggested as means of relieving menopausal symptoms. However, findings from most randomized controlled trials and one meta-analysis do not support their use.
Learn more about flaxseed, omega-3 fatty acids and other dietary supplements in the Integrative and Complementary Therapies section.
Learn about the strengths and weaknesses of different types of studies.
Study selection criteria: Randomized controlled trials with at least 60 participants and meta-analyses.
Table note: Relative risk above 1 indicates increased risk. Relative risk below 1 indicates decreased risk.
Study
|
Study Population
(number of participants)
|
Type of Supplement
|
Treatment Duration
|
Menopausal Symptoms Studied
|
Menopausal Symptoms Reduced
among Women Taking Supplements versus Placebo?
|
Randomized controlled trials
|
Tice et al. [2]
|
246
cancer-free women
|
Red clover extract
|
12 weeks
|
Hot flashes
|
No
|
Lucas et al. [3]
|
120
cancer-free women
|
Omega-3 fatty acid capsule
|
8 weeks
|
Hot flashes
|
Yes*
|
Lewis et al. [4]
|
66
cancer-free women
|
Flaxseed muffin
|
16 weeks
|
Hot flashes
|
No
|
Meta-analyses
|
Cochrane review [2,5]
|
5 studies
|
Red clover extract
|
Various
|
Hot flashes
|
No
|
* Reduced frequency of hot flashes, but not intensity of hot flashes.
References
- Rossouw JE, Anderson GL, Prentice RL, et al. for the Writing Group for the Women’s Health Initiative Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results From the Women's Health Initiative randomized controlled trial. JAMA. 288(3):321-33, 2002.
- Tice JA, Ettinger B, Ensrud K, Wallace R, Blackwell T, Cummings SR. Phytoestrogen supplements for the treatment of hot flashes: the Isoflavone Clover Extract (ICE) Study: a randomized controlled trial. JAMA. 290(2):207-14, 2003.
- Lucas M, Asselin G, Mérette C, Poulin MJ, Dodin S. Effects of ethyl-eicosapentaenoic acid omega-3 fatty acid supplementation on hot flashes and quality of life among middle-aged women: a double-blind, placebo-controlled, randomized clinical trial. Menopause. 16(2):357-66, 2009.
- Lewis JE, Nickell LA, Thompson LU, Szalai JP, Kiss A, Hilditch JR. A randomized controlled trial of the effect of dietary soy and flaxseed muffins on quality of life and hot flashes during menopause. Menopause. 13(4):631-42, 2006.
- Lethaby AE, Brown J, Marjoribanks J, Kronenberg F, Roberts H, Eden J. Phytoestrogens for vasomotor menopausal symptoms. Cochrane Database Syst Rev. (4):CD001395, 2007.
Updated 01/25/13
