Deciding whether to use hormone therapy (HT) after menopause is a difficult decision many women face as they age. Research has shown that HT is very effective for relieving menopausal symptoms such as hot flashes and vaginal dryness. It can also reduce the risk of osteoporosis. However, there are also known health risks and uncertainties about long-term use. Recent research has demonstrated that long-term use of estrogen–either alone or in combination with progestin–results in more risks than benefits.
Two studies that were part of the Women’s Health Initiative, sponsored by the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health (NIH), have been stopped because of potential health risks to the participants. The clinical trials were designed to test the effects of postmenopausal hormone therapy on heart disease, bone fractures, and breast and colorectal cancers.
One of the studies included postmenopausal women receiving estrogen combined with progestin. The study found increases in breast cancer, cardiovascular disease, stroke, and blood clots in study participants who were taking this combination compared with women taking placebo pills. This study was stopped in July 2002.
The other NHLBI study, which was stopped in February 2004, involved women taking estrogen alone. After careful review of the data, NIH concluded that estrogen alone did not significantly affect risk of either heart disease or breast cancer compared with placebo. However, similar to the estrogen-plus-progestin combination, estrogen alone increased the risk of stroke.
Both of the postmenopausal hormone therapies tested in the studies demonstrated some benefits, including a decrease in the risk of hip fracture. The combination therapy also resulted in fewer cases of colon cancer. However, on balance the harm was greater than the benefit, and these therapies should not be used to prevent chronic disease. The women in these studies are now participating in a follow-up phase, which should last until 2007.
Many women may now be considering using alternatives to conventional HT to relieve menopausal symptoms and to lower the risk of conditions such as osteoporosis and heart disease. According to a 1997 study conducted by the North American Menopause Society, more than 30 percent of women use acupuncture, natural estrogen(s), herbal supplements, or so-called plant estrogens (phytoestrogens). At this time, there is not enough scientific evidence to determine whether these therapies are beneficial. In addition, we do not have sufficient information to show whether these therapies are as safe or safer than conventional drugs being used for menopausal symptoms, osteoporosis, or heart disease.
Botanical products containing or acting like estrogens may provide some of the benefits of estrogen in relieving menopausal symptoms. For example, studies have suggested that soy food products can benefit women with mild hot flashes. Some limited research provides conflicting results on the safety and effectiveness of herbal products–such as ginseng, black cohosh, and dong quai–that are marketed for menopausal symptoms. Currently, NCCAM is funding research on several botanicals that have shown promise for reducing menopausal symptoms, including black cohosh, red clover, hops, dong quai, flax seed, and dietary soy.
Through this research, we hope to learn more about the mechanism of action as well as the safety and effectiveness of these botanical products. Studies are needed to define the possible benefits of these botanical products in promoting bone, heart, and brain health, as well as the potential risks of increasing breast, endometrial, or other cancers in diverse populations of postmenopausal women.