Mild memory loss can be a natural part of growing older. Some people are turning to the herb ginkgo biloba to enhance memory, spurred by the claims of a multi-million-dollar a year global industry. But a new study says that ginkgo biloba is useless for many people.
Ginkgo biloba is a popular dietary supplement that comes in pills and in some soft drinks. Although U.S. government drug regulators have not endorsed it as safe and effective, it is widely available in U.S. pharmacies and food markets without a doctor's prescription.
Manufacturers of ginkgo products say they enhance mental focus and improve memory and concentration.
But a study published in Wednesday's issue of the Journal of the American Medical Association casts strong doubt on those claims. "We found no discernable benefit in learning, memory or attention or concentration," he said.
Neuroscientist Paul Solomon of Williams College in Massachusetts studied 230 people aged 60 or older who were in good mental and physical health. About half were selected to take ginkgo three times a day for six weeks, which is what ginkgo supplement manufacturers recommend. The other half of the participants took placebos. After six weeks, Mr. Solomon's team of researchers tested the participants.
"We ran 14 different tests of learning, memory and attention and concentration, and on none of these tests did we find any difference between the participants in the study who took ginkgo and those who took the placebo," he said.
The people in the study agreed with this assessment, and so did companions assigned to observe them during the study.
"The patients told us their memories were no different on ginkgo or on placebo, and their companions, typically a spouse or a friend, were also unable to detect any difference," he said.
But the U.S. industry trade group representing dietary supplement manufacturers, the Council for Responsible Nutrition, says the study is not definitive. The Council's vice president for botanical science, John Cardellina, says research results on ginkgo biloba in older, healthy people have been mixed, some showing mental benefits, others showing none.
"We're looking to measure something that is actually difficult to measure and therefore the test results that you get tend to be mixed," he said.
But Mr. Cardellina says ginkgo biloba shows clearer benefits in a different group of people than the ones used in the Massachusetts study.
"Ginkgo has a huge body of evidence that shows that there is benefit in people who are in early stage mental impairment, elderly with early stage cognitive dysfunction regardless of source," he said. "I wouldn't throw away your body of ginkgo if I were you."
But Paul Solomon of Williams College says that based on his study results, it may be best to forget about ginkgo biloba. In fact, he notes that there are no medications approved by U.S. drug regulators to help people with the memory disorders that accompany aging.