A new study published in the Journal of the American Medical Association suggests that Ginkgo biloba may not help older people to prevent Alzheimer's disease if they start taking this supplement too late.

Ginkgo bioba is one of the top selling herbs in the U. S. This is used for the treatment of many conditions. For healthy people, it is used for memory enhancement, symptoms of premenstrual syndrome (PMS), and reduction of chemotherapy-induced end-organ vascular damage.

Dr. Steven DeKosky, dean of the University Of Virginia School Of Medicine, led the study and involved 3,069 healthy people age 75 or older. All participants were free of Alzheimer’s. For about 6 years, half of participants were given 120 mg of ginkgo biloba twice a day while the other half were given a placebo and it was found that 18 were diagnosed with Alzheimer's or other dementia among those who took ginkgo and 16 were diagnosed with the disease who took the placebo

“We found that giving a standardized dose of ginkgo bioba over a period of time does not slow down the incidence rate of dementia or Alzheimer’s disease,” said Dr. Steven DeKosky.

Dr. Murali Doraiswamy of Duke University Medical Center in Durham, North Carolina said, Alzheimer is an incurable disease and many interventions including statins, estrogen, anti-inflammatory drugs, vitamin E and drugs called cholinesterase inhibitors do not deliver any protective effect.

Earlier studies proved ginkgo relieves symptoms in people with Alzheimer's, so the herbal industry disagreed with the findings. Dekosky said that the best solution to prevent dementia is to have a balance in your life as well as diet. For example, eating fish and omega-3 fatty acids help people maintain cognitive function.