October 2013 Issue
Herbs for Menopausal Symptom Relief — Learn What Research Says About the Most Common Botanicals Clients May Be Taking
By Judith C. Thalheimer, RD, LDN
Vol. 15 No. 10 P. 12
As a woman nears the end of her reproductive years, her estrogen levels decrease, more often than not causing a host of unpleasant symptoms, such as hot flashes, night sweats, vaginal dryness, disrupted sleep, moodiness, and headaches. Hormone replacement therapy (HRT) can ease or eliminate symptoms, but this treatment option has been shown to have risks and side effects of its own. As a result, many women are looking to dietary and botanical supplements to help ease their menopausal transition.
According to the American College of Obstetricians and Gynecologists, as many as 75% of all women will experience hot flashes, the most common symptom of menopause. The National Institutes of Health’s consensus statement on menopause reports that, from the start of hormonal changes, up to 80% of women will experience vasomotor symptoms such as hot flashes and night sweats, up to 39% will have vaginal dryness, up to 60% will have sleep disturbances, 38% will describe mood changes, and up to 39% of women will experience urinary symptoms.
For decades, menopausal symptoms have been treated medically with HRT. Most commonly, HRT includes a mix of estrogen and progestin, though estrogen alone is used if a woman has undergone a hysterectomy. However, in 2002, the Women’s Health Initiative study found that the long-term use of estrogen/progestin therapy increases the risk of breast cancer, heart attacks, stroke, and blood clots.1
Since the potential HRT risks came to light, many women have turned to diet and supplements in an attempt to control their menopausal symptoms. According to the Natural Medicines Comprehensive Database, three of the top 10 best-selling herbal products in the United States commonly are used for addressing menopausal symptoms.
Common botanical dietary supplements promoted for the relief of hot flashes and other menopausal symptoms include soy extracts, black cohosh, red clover, dong quai, ginseng, chasteberry, and evening primrose oil. Studies of these botanical remedies are limited, and many of the existing studies are small and short-term. Moreover, the studies often can’t be compared with one another. Methodological challenges such as the natural variability of plant extracts, the fact that some products studied have more than one component, and production differences make study comparison difficult.2
Some supplements do show promise for treating menopausal symptoms, but consumers should be aware of the lack of conclusive scientific evidence and the cautions that go along with these products.
Below is a brief discussion of some of the most common botanical dietary supplements for menopausal symptom relief.
• Soy isoflavone extracts: Isoflavones are phytoestrogens, or plant chemicals that bind to estrogen receptors, acting as weak estrogens in the body when endogenous levels are low. It’s thought that taking these plant estrogens in supplement form could help balance a woman’s decreasing estrogen level during menopause.
According to the Natural Medicines Comprehensive Database, soy extracts providing 35 to 120 mg of isoflavones daily seem to be beneficial for decreasing the frequency and severity of hot flashes. Products that provide at least 15 mg of the genistein isoflavone per day have the best outcomes.
Women with a personal or family history of breast cancer shouldn’t use concentrated phytoestrogen supplements or should use them with caution.3
• Black cohosh: Black cohosh (Actaea racemosa) is promoted to help alleviate hot flashes, vaginal dryness, itching, moodiness, and depression. Anecdotal evidence indicates that many women find at least some relief when taking this supplement. While study results have been mixed and no long-term studies have been conducted, there’s some evidence of effectiveness, particularly with regard to hot flashes. Side effects include stomach discomfort and headaches.
Several recent reports of liver damage in women taking black cohosh have lead to the recommendation that users should consider periodic liver function tests.
• Red clover: While a 2002 study showed a 44% decrease in hot flashes when taking 80 mg of a red clover (Trifolium pratense) isoflavone dietary supplement (Promensil) compared with placebo, the National Center for Complementary and Alternative Medicine reported that a review of all existing evidence indicates red clover has no significant beneficial effects on menopausal symptoms.
Red clover is a source of phytoestrogens and therefore should be used with caution by women with a personal or family history of breast cancer. It shouldn’t be taken with blood thinners and may interfere with the effectiveness of tamoxifen.3
• Dong quai: Dong quai (Angelica sinensis) has been used to treat gynecological conditions in traditional Chinese medicine for more than 1,200 years.4 The only clinical trial conducted to date showed no impact on hot flashes.
Women who have uterine fibroids, blood-clotting problems such as hemophilia, or who are currently using blood thinners shouldn’t take Dong quai.4
• Ginseng: Ginseng (Panax quinquefolius) may help with fatigue, insomnia, and moodiness but doesn’t seem to help address hot flashes.3,4
• Evening primrose oil: The one small, randomized, placebo-controlled trial on evening primrose oil (Oenothera biennis) found no benefit as far as reducing hot flashes. With many reported side effects and no proof of effectiveness, this remedy generally isn’t recommended.3-5
• Chasteberry: Along with kudzu, alfalfa, hops, and licorice, chasteberry (Vitex agnus-castus) has estrogenic activity. There’s no reliable evidence that chasteberry, as well as these other herbs, help menopausal symptoms and, like other phytoestrogens, they may not be safe for women with a history of breast cancer.3
• Kava: Marketed for hot flashes and possibly effective for reducing anxiety, kava (Piper methysticum) has been associated with liver damage, and the FDA has issued a warning to patients and providers about potential harm.4
While data regarding the effectiveness of phytoestrogen extracts and other botanical supplements for treating menopausal symptoms are limited and largely inconclusive, science does demonstrate ways in which diet can help improve women’s health in the postmenopausal years.
“Mother Nature is never going to steer you wrong,” says Joan Salge Blake, MS, RDN, LDN, a spokesperson for the Academy of Nutrition and Dietetics. “Foods that are high in phytoestrogens are also full of other phytochemicals, vitamins, minerals, fiber—the whole package. Postmenopausal women are at increased risk for heart disease, weight gain, bone loss, and certain cancers. If [dietitians] help women clean up their diets, manage their weight, and increase their activity level, we will be helping them with a whole range of postmenopausal issues.”
A diet based on fruits, vegetables, whole grains, low-fat dairy products, lean meats, poultry, fish, beans, nuts, and seeds helps with weight management and provides plenty of the nutrients recommended to keep the cardiovascular system, bones, and brain healthy. It also includes lots of phytoestrogen-rich food sources to help ease the discomfort of those waning estrogen levels.
The three types of phytoestrogens—isoflavones (the most potent), lignans, and coumestans—are found in some 300 foods, including legumes (eg, beans, lentils, peas, peanuts), whole grains, nuts, and seeds as well as bean sprouts and some fruits and vegetables.6
Soy and flaxseeds are two phytoestrogen powerhouse foods. Multiple studies have shown that consuming 20 to 60 g/day of soy protein modestly decreases the frequency and severity of hot flashes.3 “Soy is a great postmenopause protein source, not only because of its high isoflavone content, but also because it’s low in saturated fat,” Salge Blake says. Soy’s omega-3 fatty acid content adds to its heart-healthy profile.
There also is evidence that 40 g (4 T) per day of dietary flaxseeds significantly improves mild menopausal symptoms such as hot flashes. Flaxseeds are high in omega-3 fatty acids, so women should be careful to consume flaxseeds instead of other dietary fats to avoid weight gain and shouldn’t consume large amounts of flaxseeds while taking blood thinners.
There are some concerns about phytoestrogen consumption by women with a personal or family history of breast cancer but, while supplements may present a cancer risk, modest amounts eaten as part of a healthful, balanced diet appear to be safe.3 Additionally, what women don’t eat may be as important as what they do. Caffeine, spices, and alcohol are known triggers of hot flashes.
“We can hope that better studies of supplements will come along in the future so that we have these additional tools,” Salge Blake says, “but getting these food components in the form Mother Nature gave them to us gives us all the benefits.”
— Judith C. Thalheimer, RD, LDN, is a freelance nutrition writer and community educator living outside Philadelphia.
1. National Heart, Lung, and Blood Institute. Facts About Menopausal Hormone Therapy. Washington, DC: National Institutes of Health; 2002. NIH Publication 05-5200.
2. NIH State-of-the-Science Conference Statement on management of menopause-related symptoms. NIH Consens State Sci Statements. 2005;22(1):1-38.
3. Natural medicines in the clinical management of menopausal symptoms. Natural Medicines Comprehensive Database website. http://naturaldatabase.therapeuticresearch.com/ce/ceCourse.aspx?s=ND&cs=&pc=12-110&cec=1&pm=5. Updated August 22, 2013. Accessed July 30, 2013.
4. Natural remedies for hot flashes. The North American Menopause Society website. http://www.menopause.org/for-women/menopauseflashes/natural-remedies-for-hot-flashes. Accessed August 4, 2013.
5. Low Dog T. Menopause: a review of botanical dietary supplements. Am J Med. 2005;118(Suppl 12B):98-108.
6. Phytoestrogens and breast cancer fact sheet. Cornell University Program on Breast Cancer and Environmental Risk Factors website. http://envirocancer.cornell.edu/factsheet/diet/fs1.phyto.cfm. Updated July 2001. Accessed August 5, 2013.