Chicago ? A new study suggests ginkgo supplements do nothing to quickly improve memory in healthy people, a finding that goes against years of well-publicized claims that helped turn the supplements into a multimillion-dollar industry.

The over-the-counter supplements are made using extract from the fan-shaped leaves of the ginkgo biloba tree.

Early studies suggested that the supplements could boost mental function in people with and without mild forms of dementia.

However, those studies had methodological flaws and were too short to measure a true effect, according to the authors of the new study.

The new study, reported in today’s Journal of the American Medical Assn., involved 230 people over age 60 who had no signs of memory impairment and found that the ginkgo supplements worked no better to improve memory than dummy pills over a six-week period. Some of the supplements are advertised to have a noticeable benefit in four weeks.

“We don’t see any benefit,” said lead author Paul Solomon, a psychology professor at Williams College.

Solomon said his study involved the same type of rigorous testing required by the Food and Drug Administration for pharmaceutical drugs, though supplements like ginkgo are not FDA-regulated. The same battery of mental tests was given at the beginning and end of the study.

While both groups’ scores improved slightly, that likely was because they’d taken the tests before, and the placebo and ginkgo patients performed equally well the second time around, Solomon said.