See What HealthDay Can Do For You
Contact Us

Ginkgo Biloba and Pregnancy Don't Mix

Memory-enhancing herbal supplement could harm fetus, study shows

FRIDAY, Sept. 21, 2001 (HealthDayNews) -- Pregnant women should stay away from ginkgo biloba if they want to protect their unborn babies, new research shows.

A small study in Detroit found that women taking one type of the popular herbal supplement had high levels of a toxin called colchicine in their placental blood. Colchicine, which is found in many plants and herbs, interferes with cell division and could lead to birth defects, the researchers say. The findings appear in this month's issue of Chemical Research and Toxicology.

"I can't say it's dangerous, but I can't say it's safe. It's better to err on the side of caution," says lead study author Howard Petty, professor of biological sciences at Wayne State University in Detroit. "Women should be careful about what they take during pregnancy. It may not be important to the woman, but it's sure important to the fetus."

For the most part, doctors already advise their pregnant patients to steer clear of herbal supplements, and "this study provides an explanation why," Petty says.

One herbal expert takes that a step further.

"I think it's a very important study," says C.W. Fetrow, a pharmacist and author of the book, The Complete Guide to Herbal Medicine. "Patients are always under the impression that herbal supplements are natural and safe. Just because they're natural doesn't always mean they're safe."

"It's just another reason to stay away from herbal supplements during pregnancy. It's too delicate a scenario. Don't even walk into the store. There are too many unknowns," he says.

Although Petty's study was small and tested only one brand of ginkgo biloba, he says he plans other studies to look more closely at the problem. A large study already is underway in Europe, he says.

The finding was an accident, Petty says. Researchers were studying pregnant women, looking for the natural anti-inflammatories their bodies produce so that their immune system does not reject a fetus. They are trying to develop something to prompt remission of diseases of the immune system, such as arthritis and lupus. After taking routine samples of placental blood from 24 pregnant women, they discovered high levels of colchicine, which is an anti-inflammatory, in five women, and the levels were high enough to be dangerous, Petty says.

"We were puzzled," he says. "Why on earth is colchicine there?"

They questioned the women about their eating habits and discovered the five women with colchicine in their placental blood all took herbal supplements. So, the researchers bought one brand of ginkgo biloba and ran chemical tests on it. The result: The toxin was in the supplement.

Even though they only tested one brand, both Petty and Fetrow say herbal supplements and their ingredients are not regulated by the federal government.

"One-third of the drugs we use today have their origins in plants, but plants have many different chemicals in them," Fetrow says.

Compounding the problem, Petty says botanists have told him that some companies put lily in their ginkgo biloba supplement to improve its memory-enhancing properties. And lily is known to have colchicine, though it often does not appear as an ingredient on the supplement's label.

"The lack of standardization rears its ugly head and shows us this problem again," says Fetrow.

Ginkgo biloba, which is extracted from the leaves of the ginkgo tree, typically is used to treat Alzheimer's disease and memory loss in older people. Scientists believe it improves blood flow to the brain, although it can cause skin rashes. It is one of the 10 most-popular herbs in America, and more than 10 million people take it.

What To Do

Here's more on ginkgo biloba. And check this CNN story on ginkgo's memory-enhancing abilities.

The National Institute on Aging has more information on the use of ginkgo biloba for Alzheimer's disease.

SOURCES: Interviews with Howard Petty, professor, biological sciences, Wayne State University, Detroit; C.W. Fetrow, Pharm.D., clinical pharmacist, UPMC, Passavant Hospital, Pittsburgh, Pa.; Sept. 17, 2001, Chemical Research and Toxicology
Consumer News