Black Cohosh & Liver

Supplementation with the herb black cohosh aims to limit the hot flashes and other symptoms of menopause. A series of studies attempting to investigate this potential benefit have yielded mixed results. Furthermore, the reporting of several cases of adverse effects, including liver damage, suggests caution in utilization of this supplement. Always talk to your doctor before trying to use black cohosh to treat yourself.

Features

Black cohosh is a perennial plant native to North America that has a long medicinal history including use by the Native Americans for a number of ailments. Currently, you can purchase extracts from the roots or stems in wide range of doses derived from different extraction methods. The variation in dosing and preparation methods complicates interpretation of different research studies and investigation of reports of liver damage, warns the National Institutes of Health.

Effects

While the exact mechanisms of its action remain to be elucidated, researchers believe that black cohosh possesses estrogenic activity. As levels of estrogen and other hormones fall sharply following the onset of menopause, supplementation with black cohosh may activate estrogen receptors and limit the effects of decreased circulating hormone levels. Estrogen receptors exist in a number of tissues, including reproductive organs, the cardiovascular system, and the liver. The widespread distribution of estrogen receptors suggests that use of a compound that leads to their activation may cause a number of effects in various organ systems.

Benefits

In a number of short clinical trials ranging from three to six months, daily administration of black cohosh produced a benefit similar to hormonal supplementation. Black cohosh reduced the symptoms of menopause as well as significantly decreased the number of hot flashes per day, according to the National Institutes of Health. Additional benefits observed include preventing vaginal changes associated with reduced estrogen. Some alternative medicine practitioners also recommend black cohosh for lowering cholesterol in the blood, purportedly due to its estrogenic effects on the liver.

Considerations

Findings from studies utilizing short time periods of administration indicate there is some benefit from black cohosh on alleviating the symptoms of menopause. However, large scale and longer time course studies failed to produce positive findings. As with studies investigating the effects on menopausal symptoms, clinical trials investigating the effects of black cohosh on lipid metabolism and liver function demonstrated no significant effect.

Warnings

Several case reports indicate a potential risk for liver damage with black cohosh supplementation. While this has not been reproduced in large clinical trails, these reports led to governmental warnings in North America and Europe. The sale and production of black cohosh and other supplements are largely unregulated. Thus, despite the need for additional long-term study, the lack of liver damage in clinical trials led some to attribute the negative effects to impure black cohosh preparations or other substances in the supplement.