The popular herbal remedy ginkgo biloba may raise the risk of seizures in people with epilepsy. German scientists, writing in the Journal of Natural Products, said they were convinced the herb could have a "detrimental effect."

Ginkgo biloba is used as a remedy for many health maladies including Alzheimer's, depression, and headaches.

The researchers found that a chemical compound in the herb called ginkgotoxin might modify a chemical-signaling pathway in the body and trigger seizures.

After a review of 10 studies, they concluded that ginkgo might also interfere with anti-seizure drugs and reduce their effectiveness, although there was no definite proof.

Professor John Duncan of the British National Society for Epilepsy says that the evidence doesn't justify restrictions on the herb, but epileptics should be aware of the possible danger. "We believe that some herbs, for example St. John's wort, are linked to a higher risk of seizures, but there is still not a great deal of evidence about problems related to ginkgo," he told BBC News.

"We would say that if someone who has epilepsy wants to take this remedy, they should simply be aware of the possibility."

Triggers for epileptic seizures vary from person-to-person and should be avoided whenever possible. According to the Epilepsy Foundation, they include:

• Lack of sleep
• Alcohol
• Stress
• Flashing lights
• Fatigue