Red Clover : Uses and Health Benefits

by MedlinePlus

Red clover is a legume, which like soy contains "phytoestrogens" (plant-based chemicals that are similar to estrogen, and may act in the body like estrogen or may actually block the effects of estrogen). Red clover was traditionally used to treat asthma, pertussis, cancer, and gout. In modern times, isoflavone extracts of red clover are most often used to treat menopausal symptoms, as an alternative hormone replacement therapy, for high cholesterol, or to prevent osteoporosis. However, at this time, there are no high-quality human studies supporting the use of red clover for any medical condition.

Synonyms

Ackerklee (German), beebread, cow clover, genistein, isoflavone, isoflavone clover extract (ICE), meadow clover, phytoestrogen, Promensil®, purple clover, Rimostil®, Rotklee (German), trefle des pres (French), trefoil, trifolium pratense, Trinovin®, wild clover.

Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidence

Cardiovascular - blood flow

Red clover has been shown to improve the flow of blood through arteries and veins. However there is limited study in this area and more research is needed before a conclusion can be drawn.

Diabetes

Red clover has been studied in patients with type 2 diabetes to determine potential benefits in diabetic complications such as high blood pressure and narrowing of the arteries and veins.A small randomized, controlled trial studied postmenopausal women with type 2 diabetes. Women were given red clover (approximately 50mg/day) for 4 weeks and the effects were compared to placebo. Improvements were seen in blood pressure and in the function of the veins and arteries.Another small randomized, controlled clinical trial studied the effects of red clover (86mg/day) on blood lipids and insulin in pre-menopausal women. The study followed 12 pre-menopausal women for 3 cycles and found that there was no change in the women's lipid profile or their blood sugar or insulin levels.Further research is needed before a recommendation can be made. If you have diabetes you should contact your health care professional before taking red clover.

High cholesterol

Red clover has not been clearly shown to have beneficial effects on blood cholesterol levels. One small randomized, controlled clinical trial studied the effects of red clover (86mg/day) on blood lipids and insulin in pre-menopausal women. The study followed 12 pre-menopausal women for 3 cycles and found that there was no change in the women's lipid profile or their blood sugar or insulin levels. Due to conflicting study results, further research is needed in this area before a recommendation can be made.

Hormone replacement therapy (HRT)

Laboratory research suggests that red clover isoflavones have estrogen-like activity. However, there is no clear evidence that isoflavones share the possible benefits of estrogens (such as effects on bone density). In addition, hormone replacement therapy itself is a controversial topic, with recent research reporting that the potential harm may outweigh any benefits.

Menopausal symptoms

Laboratory research suggests that components of red clover called isoflavones have estrogen-like activity. Red clover isoflavones are proposed to reduce symptoms of menopause (such as hot flashes), and are popular for this use. Blood pressure and triglyceride levels may be lowered. However, most of the available human studies are poorly designed and short in duration (less than 12 weeks of treatment).In a well conducted, multicenter randomized, controlled clinical trial the safety and efficacy of two brands of red clover were studied as well as the effects of both brands compared to placebo on hot flashes. The two brands of red clover were Promensil® (82mg of red clover), and Rimostil® (57mg of red clover). The study included 252 postmenopausal women aged 45 to 60 years who were experiencing at least 35 hot flashes a week, and excluded vegetarians, those who consumed soy products more than once a week or took medications that would affect the absorption of the red clover. The study found that neither supplement had a significant effect on hot flashes or other symptoms of menopause.Another randomized, controlled clinical trial studied the effects of red clover (Promensil®) versus placebo on hot flashes. This was a smaller study and included only 30 postmenopausal women who were experiencing more than 5 hot flashes a week. This study found that red clover supplementation (Promensil®, providing 80mg of red clover) significantly decreased the amount of hot flashes that the women experienced.As results of published studies conflict with each other, more research is needed before a clear conclusion can be drawn.

Osteoporosis

It is not clear if red clover isoflavones have beneficial effects on bone density. Most studies of isoflavones in this area have looked at soy, which contains different amounts of isoflavones, as well as other non-isoflavone ingredients. More research is needed before a recommendation can be made.

Prostate cancer

Red clover isoflavones may have estrogen-like properties in the body, and have been proposed as a possible therapy in prostate cancer and related hot flashes. Some isoflavones have also been shown in laboratory studies to have anti-cancer properties. Because there is no-well designed human research in this area, a recommendation cannot be made.

Prostate enlargement (benign prostatic hypertrophy)

There is only limited study of red clover for benign prostatic hypertrophy. More research is needed before a firm conclusion can be drawn.

Uses based on tradition or theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Acne, AIDS, antibacterial, antioxidant, anti-spasm, appetite suppressant, arthritis, asthma, blood purification, breast cancer prevention, bronchitis, burns, cancer, cancer prevention, canker sores, cardiovascular disease, cognitive function, cough, chronic skin diseases, diuretic (increase urine flow), eczema, endocrine responsive cancer, gout, hot flashes, increasing HDL cholesterol, indigestion, mastalgia (breast pain), osteosarcoma, premenstrual syndrome, psoriasis, sexually transmitted diseases, skin ulcers/sores, sore eyes, tuberculosis, whooping cough (pertussis).

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Standardization

Standardization involves measuring the amount of certain chemicals in products to try to make different preparations similar to each other. It is not always known if the chemicals being measured are the "active" ingredients. The brand of red clover extract used in most trials, and which is most commonly available, is Promensil®. Each tablet, composed of 40 milligrams total isoflavones, is standardized to contain the following components: 4 milligrams genistein; 3.5 milligrams daidzein; 24.5 milligrams biochanin A; and 8.0 milligrams formononetin.

Adults (18 years and older)

Benign prostatic hypertrophy: 40 milligrams of red clover isoflavones per day (Trinovin®) has been studied.

Breast cancer prevention: A red clover-derived isoflavone tablet containing 26 milligrams biochanin A, 16 milligrams formononetin, 1 milligram genistein and 0.5 milligram of daidzein has been studied.

Cardiovasuclar disease: 86 milligrams per day for 1 month has been studied.

Diabetes: 50 milligrams and 86 milligrams per day of red clover isoflavones per day have been studied for diabetic complications.

High cholesterol: 28 to 86 milligrams of red clover isoflavones per day (Rimostil®), or 80 milligrams of red clover isoflavones per day (Promensil®) has been studied.

Hormone replacement: 40 to 80 milligrams of red clover isoflavones per day (Promensil®) has been studied. Red clover-derived isoflavone supplement that provided a daily dose of 26 milligrams biochanin A, 16 milligrams formononetin, 1 milligram of genistein, and 0.5 milligrams of daidzein was studied for 1 year for bone density. Another study used 50 milligrams per day for 4 weeks. Several studies provided red clover in Promensil (82 milligrams total isoflavones) or Rimostil® (57.2 milligrams total isoflavones) forms.

Menopausal symptoms: 40 milligrams, 80 milligrams, or 160 milligrams of red clover isoflavones per day (Promensil®) has been studied. Rimostil® (57 mg of red clover) has also been used. Red clover-derived isoflavone supplement that provided a daily dose of 26 milligrams biochanin A, 16 milligrams formononetin, 1 milligram of genistein, and 0.5 milligrams of daidzein was studied for 1 year for bone density. Another study used 50 milligrams per day for 4 weeks. Several studies provided red clover in Promensil (82 milligrams total isoflavones) or Rimostil® (57.2 milligrams total isoflavones) forms.

Osteoporosis: 40 milligrams of red clover isoflavones per day (Promensil®) has been studied. Red clover-derived isoflavone supplement that provided a daily dose of 26 milligrams biochanin A, 16 milligrams formononetin, 1 milligram of genistein, and 0.5 milligrams of daidzein was studied for 1 year for bone density. Another study used 50 milligrams per day for 4 weeks. Several studies provided red clover in Promensil (82 milligrams total isoflavones) or Rimostil® (57.2 milligrams total isoflavones) forms.

Children (younger than 18 years)

There is not enough scientific evidence to recommend use of red clover in children.

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