Special Diets

• By Suzanne Dixon, MPH, MS, RD

Ginkgo Doesn’t Help Brain Function? Not So Fast

The herb Ginkgo biloba has been studied and used for years as a way to manage mild age-related decline in thinking (cognition), and more serious dysfunction caused by Alzheimer’s and related diseases. The results of the just-published Ginkgo Evaluation of Memory (GEM) study has generated a lot of press that might leave some people with the impression that ginkgo is ineffective. But, just like most science, the results of a single study—especially when taken out of context—are not the whole story. In fact, ginkgo has been shown in other studies to produce a modest improvement in cognitive function in people who already have Alzheimer’s disease and other types of dementia.

Despite recent findings, the body of research shows ginkgo may still benefit certain people

Study conclusions contain no GEMs of wisdom

GEM was a randomized, double-blind, placebo-controlled trial of 3,069 participants, who were 72 to 96 years old at the time of entry into the study. The researchers compared changes in cognitive function over time in people who took 120 mg of ginkgo twice a day with changes in those who took a placebo.

After following the study participants for about six years, the researchers noted no differences in the rates of decline in memory, attention, visual-spatial abilities, language, and higher-level thinking (executive function) between the two groups. The authors acknowledged some study limitations, but these were not reported in most news stories. Organizations such as the American Botanical Council have given them more attention, pointing out, for example, that the average age of participants was 79 years, which is much older than the typical age at which many people first begin using ginkgo to improve mental performance. Other factors, such as the high drop-out rate (over 40%) and some baseline data that wasn’t part of the study’s original design make this topic worth continued examination.

What’s the bottom line about ginkgo, cognitive function, and memory?

While the new study adds useful information to the picture on ginkgo and cognitive function, it is not the final word. As mentioned, studies to date suggest that ginkgo produces a modest improvement in cognitive function in people who already have Alzheimer’s disease and other types of dementia. According to Alan R. Gaby, MD, chief science editor at Aisle7, the research shows that in these people, benefits have been seen to persist for a year or longer with continued use. While ginkgo has not been shown to help people with normal cognitive function or mild age-related cognitive impairment, since Alzheimer’s and other more serious dementias have very few treatment options, the potential benefits to people with those diseases should be explored.

Train your brain

To keep your brain sharp, a multifaceted approach is your best bet. If you decide to include ginkgo, talk to your doctor first—especially if taking any medications. Also focus on the following proven ways to boost brain health:

• Keep your ticker healthy. The same changes that lead to heart disease can lead to brain dysfunction. Focus on the lower-fat, high-fiber, fruit-and-vegetable-rich diet known to protect heart health. Your brain will benefit as well.
• Go for color. Many of the phytonutrients and antioxidants that give vegetables and fruit their bright orange, red, green, yellow, and purple colors are thought to protect brain cells from damage as we age.
• Stay slim and trim. Obesity and overweight can lead to cognitive decline because they impair the way the body and brain process nutrients, contribute to cell-damaging inflammation, and lead to reduced blood flow in the brain.
• Get moving. Regular exercise is a proven brain-booster. Exercise increases the flow of blood and nutrients to the brain and the removal of waste products from it.
• Stay mentally active. Enjoy card games or crossword puzzles. Read a good book. Take up a new hobby. Whatever you can do to engage your brain will keep you sharp as you age.
• Be a socialite. Have regular visits with family and friends. Strong social connections are an important part of healthy brain aging.

(JAMA 2009; 302:2663–70)