June 22, 2017 -- From eating blueberries to playing brain training games, researchers have been searching for ways we can prevent memory loss and dementia as we age.
An expert panel that reviewed the research behind hundreds of studies finds that three strategies may help lower the odds of memory loss. These are:
- Getting regular exercise
- Managing blood pressure
- Doing “brain training”
But the conclusion comes with a strong caution that the evidence is modest and doesn’t prove the strategies can prevent the brain disease. Still, the report, released today by the National Academies of Sciences, Engineering and Medicine offers hope that lifestyle changes could help prevent decline in thinking and memory.
"I think the bottom line is, there are some areas of hope and encouragement," says panel member Dan Blazer, MD, PhD, of Duke University School of Medicine in Durham, NC.
To create the 149-page report, titled “Preventing Cognitive Decline and Dementia: A Way Forward,” the expert panel evaluated evidence from hundreds of studies called randomized clinical trials, considered the gold standard for scientific research. They also looked at evidence from other types of research.
Preserving memory and thinking skills is especially crucial. More than 5 million Americans now have Alzheimer's disease, the most common form of dementia, according to the Alzheimer's Association. By 2050, the numbers could reach 16 million. Treatments are elusive, with no new drugs approved for more than a decade. Those drugs that are approved may help slow the disease but are not a cure.
The panel stopped short of recommending everyone use the strategies, saying they need more research that shows how well they work.
More on the Top 3 Strategies
Some research has found that managing high blood pressure, especially from ages 35 to 65, lowers the chance of having dementia.
While previous research has found that some blood pressure drugs can cut the odds of having Alzheimer's better than others, what seems to matter most, is not the specific drug used but that blood pressure is controlled, Blazer says.
Research has also linked regular exercise with a healthy brain, but the studies reviewed were not consistently positive, the panel found. "Exercise is a good thing," Blazer says. But there's not enough research to pinpoint how much is needed or what type of exercise is best.
Brain training includes a variety of activities, such as computer-based and non-computer-based training exercises to improve memory, problem solving, and other skills. The panel singled out a study known as ACTIVE (Advanced Cognitive Training for Independent and Vital Elderly), funded by the National Institutes of Health, as having the strongest design. It found ''moderate strength'' evidence at 2 years that the training can improve how well your brain works, but the results lessened after 5 years.
The researchers are working on a commercial version of the training program, which is not yet available to the public, says lead researcher George Rebok, PhD.
What About Diet?
Claims about diets for brain health are plentiful. In one of the latest studies released this week, Temple University researchers found that extra-virgin olive oil helped stave off Alzheimer's, at least in mice. Those fed a diet enriched in extra-virgin olive oil could learn and remember better than those not fed the diet.
The panel did not find enough evidence to recommend any specific diet. But it did single out three diets as showing promise: the Mediterranean, the DASH (Dietary Approaches to Stop Hypertension), and the MIND diet (Mediterranean-DASH Intervention for Neurodegenerative Delay). The diets emphasize eating whole grains, fruits and vegetables, and low-fat dairy, and keeping salt in check.
"Diet deserves more study," Blazer says. "It doesn't reach the level of evidence that exercise does.”
The panel found no benefit from:
- Antidementia drugs, also known as acetylcholinesterase inhibitors. While the drugs are used to treat the symptoms of Alzheimer's, none treat the underlying cause or slow the worsening of the disease, the panel says. The research also shows they didn’t help memory and thinking skills in those with mild cognitive impairment or MCI, which happens before dementia.
- Nonsteroidal anti-inflammatory drugs (NSAIDS), such as aspirin, ibuprofen, and naproxen
- Gingko biloba, a popular herbal supplement
- Vitamin E
Keith Fargo, PhD, director of scientific programs for the Alzheimer's Association, says the association agrees with the ''top three'' strategies the expert panel developed.
Fargo adds that while the panel found dietary evidence inconclusive, the association believes there is moderate evidence that the Mediterranean diet or a similar one, such as DASH, may help lower the chance of having dementia.
Gary Small, MD, director of the UCLA Longevity Center, says the report’s conclusions make sense.
"Intuitively, we know that what is good for your heart is going to be good for your brain," he says, referring to blood pressure control and exercise findings. While it's not yet proven by research that these practices will also lower the odds of having dementia, the strategies are good for your overall health, he says.
Ross Andel, PhD, a gerontologist and professor of aging studies at the University of South Florida in Tampa, has found in his own research that exercise at midlife can lower the chance of dementia by half. Even so, Andel says, ''there's a tremendous amount of work to be done before we can make any recommendations to the public." With cancer and heart disease, he says, ''we have made great strides forward. There are ways to reduce risk." Not so for dementia, he says.
"And the issue is magnified by the fact that there is no definitive treatment for dementia," Andel says.