Red Clover: Benefits, Dosage, Contraindications
Other name(s)
Meadow Clover, Purple Clover
Scientific name(s)
Trifolium pratense
Family or group:
Plants
Active ingredients:
Coumarins
Phytoestrogens
Apigenin
Isoflavones
Indications
Rating methodology
EFSA approval.
Osteoporosis ✪✪✪✪✪
Menopause is associated with an increased risk in women of developing osteoporosis, i.e., significant bone loss. A double-blind, randomized, placebo-controlled clinical study involving 177 women who took a standardized extract (43.5 mg of isoflavones per day) or a placebo for one year, showed that, compared to the placebo, the isoflavone extract significantly reduced bone loss. However, most clinical evidence suggests that taking red clover does not improve osteoporosis-related parameters. Another clinical study shows that taking a specific red clover extract providing 40 mg of isoflavones per day for a year does not significantly increase hip bone mineral density but reduces lumbar spine bone density loss in women aged 49 to 65. The benefit is unclear, more studies are needed to understand the mechanisms.
Posologie
Orally
30 - 80 mg
1 - years
standardized isoflavone extract
Effect of an isoflavones-containing red clover preparation and alkaline supplementation on bone metabolism in ovariectomized rats.
Effects of phytoestrogenic isoflavones from red clover (Trifolium pratense L.) on experimental osteoporosis.
The effects of phytoestrogen isoflavones on bone density in women: a double-blind, randomized, placebo-controlled trial.
Dyslipidemia ✪✪✪✪✪
Results are contradictory, but clinical studies show that taking a red clover extract providing 80 mg of isoflavones per day may reduce total cholesterol and LDL in post-menopausal women with a high body mass index (BMI).
Posologie
Orally
50 - 200 mg
18 - months
standardized isoflavone extract
Red clover isoflavones enriched with formononetin lower serum LDL cholesterol-a randomized, double-blind, placebo-controlled study.
A biochanin-enriched isoflavone from red clover lowers LDL cholesterol in men.
Menopause ✪✪✪✪✪
It has been established that red clover, thanks to its isoflavones, can help stimulate the low levels of estrogens in the body, particularly during menopause in women. In these conditions, researchers have demonstrated that an isoflavone-rich extract, which imitates the estrogen-like effects in the body, could relieve some of the symptoms of menopause and be used in hormone replacement therapy. Furthermore, due to ovarian insufficiency, post-menopausal women tend to develop a more atherogenic profile. Red clover extracts have a beneficial action on the lipid profile. In fact, several studies have verified that red clover consumption by peri-menopausal and post-menopausal women results in a significant decrease in total cholesterol, low-density lipoprotein cholesterol (LDL-C), and triglycerides, as well as a significant increase in HDL-C. However, several clinical trials show that taking red clover extract orally for 12 weeks to a year does not significantly reduce menopause symptoms such as hot flashes or night sweats. Nevertheless, some data indicate that taking a specific red clover supplement containing a high proportion of the biochanin A and genistein constituents could provide some advantage. Thus, taking 80 mg of red clover isoflavones per day reduces menopause symptoms compared to a placebo.
Posologie
Orally
80 - 160 mg
1 - years
standardized isoflavone extract
Combined Red Clover isoflavones and probiotics potently reduce menopausal vasomotor symptoms.
Clinical effects of a proprietary combination isoflavone nutritional supplement in menopausal women: a pilot trial.
Isoflavones from red clover (Promensil) significantly reduce menopausal hot flush symptoms compared with placebo.
The effect of red clover isoflavones on menopausal symptoms, lipids and vaginal cytology in menopausal women: a randomized, double-blind, placebo-controlled study.
Properties
Estrogenic Action
The constituents of isoflavones, biochanin A and genistein, have been reported to have relatively high levels of estrogenic activity. Daidzein seems to be less active. However, biochanin A, formononetin, genistein, and daidzein do not have observable progestogenic or androgenic effects. Isoflavones, like those in red clover, are considered phytoestrogens, plant compounds with a structure similar to estradiol and capable of binding to estradiol receptors. Isoflavones therefore have similar activity to estrogens and preferentially bind to the beta estrogen receptor, but with much lower affinity than estradiol. Biochanin is converted to genistein and formononetin is converted to daidzein. Genistein has a binding affinity 20 to 30 times higher to the beta estrogen receptor compared to the alpha estrogen receptor. The beta estrogen receptor is found in the vascular system, brain, bones, and heart, as opposed to the alpha estrogen receptor, which is in the ovaries, breast, uterus, and adrenal glands.
Usages associés
Bone Density
In animal research, the isoflavones genistein and daidzein have been shown to stimulate osteoblastic function. According to research conducted in post-menopausal women, it's unclear to what extent bone loss is affected by dietary isoflavones such as those found in red clover. Nonetheless, some trials conclude a slight attenuation (less than 5%) of the rate of lumbar bone mineral density loss in women after supplementation with red clover extract. This supplementation does not seem to significantly influence bone mass or the rate of bone loss.
Usages associés
Cardiovascular
Multiple studies show that red clover may help in the prevention and treatment of heart diseases. Indeed, some scientific studies have revealed that it notably reduces LDL (bad) cholesterol levels. Interestingly, the isoflavones present in clover could increase HDL or good cholesterol in both pre- and post-menopausal women.
Usages associés
Antioxidant
The antioxidant properties of red clover have been attributed to the genistein of the isoflavones. Genistein inhibits the formation of hydrogen peroxide and superoxide anion and scavenges hydrogen peroxide in vitro. Daidzein also appears to possess antioxidant properties, though to a lesser extent.
Dermatological Effect
In human research, the topical co-administration of a red clover flower extract and a biomimetic peptide has positively modified the proportion of anagen and telogen hair growth in people with alopecia. According to researchers, the presumed mechanisms of action include the reduction of inflammatory reactions, inhibition of 5-alpha-reductase activity, and local stimulation of matrix protein synthesis in the hair follicle.
Safety dosage
Adult: 250 mg - 500 mg
Supplementation with red clover extract provides 40 mg of total isoflavones taken once daily, or two doses totaling 80 mg of isoflavones per day. Assuming that red clover extracts contain 8% isoflavones, this brings the dosages to 500 mg. It should be noted that all dosages in studies concern the isoflavones contained in red clover extracts. Therefore, almost all extracts studied are standardized to isoflavones.
Interactions
Médicaments
Oral contraceptives: mild interaction
Some contraceptive pills contain estrogen. Red clover might exert activity similar to estrogen. However, red clover is not as potent as the estrogen contained in contraceptive pills. Taking red clover with contraceptive pills might reduce their effectiveness. Among these contraceptive pills are: ethinyl estradiol and levonorgestrel (Triphasil), ethinyl estradiol and norethindrone.
Estrogens: mild interaction
Taking red clover with estrogen pills might reduce their effects. Among these estrogen pills are: conjugated equine estrogens (Premarin), ethinyl estradiol, and estradiol.
Tamoxifen: mild interaction
Estrogen-sensitive cancers are cancers that are affected by estrogen levels in the body. Tamoxifen (Nolvadex) is used to help treat and prevent these types of cancer. Red clover also appears to affect estrogen levels in the body. By affecting estrogen levels in the body, red clover might reduce the effectiveness of tamoxifen (Nolvadex). Do not take red clover if you are taking tamoxifen (Nolvadex).
Methotrexate: mild interaction
Red clover might increase methotrexate levels in the body and possibly enhance the adverse effects of methotrexate, such as vomiting and stomach pain.
Precautions
Breast cancer: use with caution
Red clover might act like estrogen.
Hormone-sensitive conditions: use with caution
Red clover might act like estrogen.
Protein S deficiency: avoid
People with protein S deficiency have an increased risk of blood clots. Since red clover acts like an estrogen hormone, red clover might increase the risk of blood clots.
Surgery: avoid
Red clover might slow blood clotting. It could increase the risk of excessive bleeding during and after surgery. It is advised to stop taking red clover at least two weeks before the operation.
Pregnant woman: avoid
Red clover acts like estrogen and might disrupt the balance of important hormones during pregnancy or breastfeeding. Avoid all use.
Breastfeeding woman: avoid
Red clover acts like estrogen and might disrupt the balance of important hormones during pregnancy or breastfeeding. Avoid all use.
