Echinacea And St. John's
Herbs Could Impair Fertility
WASHINGTON - Several popular over-the-counter herbs, including St. John's Wort and echinacea, could badly affect people's fertility, researchers said on Monday.
A study published in the journal Fertility and Sterility suggests that high doses of echinacea, ginkgo and St. John's wort can damage reproductive cells, can stop sperm from fertilising eggs and might damage eggs and sperm.
St. John's Wort is sold widely for use in treating depression and anxiety, and has been shown in clinical tests to help, while gingko biloba is marketed for boosting memory and can help Alzheimer's patients.
Echinacea is sold to boost the immune system to fight off colds and flu.
The team at Loma Linda University School of Medicine in California said St.John's Wort in particular both impaired the ability of the sperm to penetrate the egg and seemed to cause genetic mutations in the sperm.
"This is a very important study that could provide important information to patients suffering from infertility,'' Alan DeCherney, editor of Fertility and Sterility, said in a statement.
"The growing popularity of these herbal products means we must examine all their possible side effects.''
The researchers did not test people taking the herbal preparations but instead worked in the laboratory.
They took hamster eggs, removed the zona pellucida or outer shell-like coating, exposed them to the herbs and then mixed in human sperm. Healthy human sperm usually can penetrate the egg, but will not fertilise it.
At very low concentrations there was no effect, but at higher doses St. John's Wort prevented the sperm from penetrating the eggs. Echinacea and gingko impaired penetration, and palmetto, sold to help prostate problems, had no measurable effect.
Sperm exposed to St. John's Wort for more than a week were damaged, the researchers added.
Tests will have to be done on people to see if the effect carries over to humans. It will also have to be shown that such herbs do get carried to the reproductive system when people take them.