Herbs & Supplements

Who is this for?

Uses

Because it contains chemicals called isoflavones, which belong to a larger class of plant chemicals known as phyto (plant-derived) estrogens, red clover is often taken to relieve symptoms of premenstrual syndrome (PMS). Isoflavones are similar in shape to the female hormone, estrogen. Therefore, they may attach to estrogen receptors throughout the body--particularly in the bladder, blood vessels, bones, and heart. For women with normal estrogen levels, red clover isoflavones may displace some natural estrogens, possibly preventing or relieving estrogen-related symptoms, such as breast pain, that are associated with PMS. This effect may also reduce the possibility of developing estrogen-dependent cancer of the endometrium (the lining of the uterus). In addition, results from a review of nearly 1,000 women suggest that red clover may interfere with an enzyme known to promote the progression of endometrial cancer. Red clover may also block enzymes thought to contribute to prostate cancer in men. However, red clover isoflavones may actually cause some types of existing breast tumors to grow faster.

In postmenopausal women, who generally have low blood levels of estrogen, red clover may act as hormone replacement. Taking it may relieve some menopause symptoms that are associated with low estrogen levels. Clinical studies have been inconclusive, however, in determining whether or not red clover isoflavones are effective at lessening the number or extent of hot flashes associated with menopause. Some study participants experienced various degrees of relief from hot flashes, while others observed no changes. Before red clover can be recommended, more studies are needed to determine whether it has any effects on cancer or the symptoms of menopause and PMS.

Taking red clover has been shown to help delay osteoporosis in women who have not yet reached menopause. The estrogen-like effect of red clover isoflavones may be involved, and red clover also may have a direct effect by preventing the breakdown of existing bone. However, this possible bone-strengthening effect has not been seen in men or post-menopausal women. Red clover has shown a definite limiting effect, however, in the development of benign prostate hyperplasia (BPH), which is a non-cancerous enlargement of the prostate gland. An enlarged prostate may cause men to experience a weak or interrupted urine stream, dribbling after urinating, or the urge to urinate even after voiding. For most men, BPH is a normal part of aging.

Red clover may also help to prevent heart disease in several ways. Although results from human studies are not definite, some show that taking red clover may lower blood levels of C-reactive protein, total cholesterol, triglycerides, and "bad" low-density lipoprotein (LDL) cholesterol--all factors that contribute to heart disease. At the same time, red clover may raise the levels of "good" high-density lipoprotein (HDL) cholesterol in the body. In addition, red clover may also promote an increase in the secretion of bile acid. Because cholesterol is a major component of bile acid, increased bile acid production usually means that more cholesterol is used and less cholesterol circulates in the body. Additionally, red clover contains small amounts of chemicals known as coumarins, which may help keep the blood from becoming thick and gummy. Therefore, the possibility of forming blood clots and arterial plaques may be reduced. Plaques are accumulations of blood cells, fats, and other substances that may build up in blood vessels, possibly reducing or blocking blood flow. Red clover may also help the arteries remain strong and flexible (a quality often called "arterial compliance"), which may also help to prevent some of the plaque deposits that may lead to a heart attack or a stroke.

Topical red clover preparations are used to treat various types of skin conditions. In folk medicine, fresh red clover flowers have been chopped or mashed and applied directly to skin wounds such as insect stings or snake bites. More recently, creams, lotions, or ointments containing red clover extract have been studied for treating psoriasis and other skin conditions. While all of these results need further documentation, animal studies have shown that red clover preparations may also protect skin against sunburn and damage caused by exposure to sunlight.