Remember this: Benefits of ginkgo are minor

The products: Some people are born with lightning-quick minds and steel-trap memories. The rest of us -- the ones who instantly forget names and struggle to follow the plot lines of “Law & Order” -- have to carefully cultivate our brainpower.

Reading, working on crossword puzzles and regular exercise can all help keep the mind sharp. If you’re seeking a quicker mental boost, there’s no shortage of pills and supplements that promise to improve memory, focus and overall thinking skills.

The star of the memory business is Ginkgo biloba, a tree that, as ads often remind us, has been used medicinally for thousands of years. Ginkgo supplements, widely available at health food stores and over the Internet, come in many guises. You can buy ginkgo on its own, but most products combine the herb with other ingredients.

Brain Advantage, for example, contains ginkgo along with Chinese skullcap, acacia and bacopa. Advanced Ginkgo Smart adds eight other supposedly memory-enhancing ingredients, including the natural brain chemicals choline and DMAE.

Users of Brain Advantage are told to take two capsules a day with meals. A month’s supply costs about $30. The suggested dose of Advanced Ginkgo Smart is one or two capsules each day: Two capsules each day would add up to about $15 a month.

The claims: Ads for ginkgo supplements leave the impression that a few pills can awaken the astrophysicist within anyone. The Brain Advantage website calls its product “nature’s way to help keep your mind incredibly sharp and active.” Ads for Recall Factor, another ginkgo-based supplement, say that users no longer have to worry about drifting concentration at work or losing thoughts in the middle of a conversation. Ads for Advanced Ginkgo Smart call it “the most sophisticated cognitive formula on the market” and claim that it enhances “memory, mental clarity, concentration, alertness and focus.”

Some ads mix in science. Pitches for Advanced Ginkgo Smart claim that ginkgo “enhances blood flow to the brain.” Other ads tell us that the antioxidants in ginkgo protect brain cells from age-related damage.

Bottom line: Ginkgo may be the most scrutinized supplement to ever hit health store shelves. There have been hundreds of ginkgo studies, including many classic rats-in-a-maze-type investigations and dozens of human trials. According to Fernando Gomez-Pinilla, a professor of neurosurgery at UCLA and a spokesperson for the Society for Neuroscience, the bulk of these studies point in the same direction: Ginkgo probably can help improve thinking, but not by much. “It won’t make you a genius,” he says.

Ginkgo contains several compounds that seem to stimulate blood circulation and perk up brain cells, Gomez-Pinilla says. On average, he says, based on the studies, daily doses of supplements containing 120 milligrams to 240 milligrams of ginkgo should help boost memory and overall thinking skills by about 5% to 10%. For some, he says, that could mean memorizing longer lists or absorbing more information from a book.

People who already have declining brainpower -- including those with age-related memory loss or early Alzheimer’s disease -- probably have the most to gain, he says. “For people who are performing at a high level, the changes will be very small.”

In some cases, the benefits are small enough to be essentially invisible. A four-month Stanford study of 90 high-functioning adults ages 65 to 84, published in March, found no real differences between a placebo and a supplement containing 160 milligrams of ginkgo in 5 of 6 thinking tasks.

Make that almost no difference: In the sixth task -- which measured the ability to memorize a list -- subjects taking the placebo outperformed patients taking ginkgo. “My personal feeling is that the verdict on ginkgo isn’t in yet,” says lead author Joseph Carlson, now the director of radiology, sports and cardiovascular nutrition at Michigan State University. Still, Carlson says, the herb may be worth a try, especially for people with dementia. “It might be a good addition to their treatment,” he says.

Ginkgo can potentially increase the risk of bleeding, especially when combined with aspirin or blood thinners, so users should consult their doctors. “For healthy people who take it in regular doses, it should be safe,” Gomez-Pinilla says.

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