OCTOBER 2009

Is there anything you can do to reduce your risk of cognitive decline and dementia? Research presented at the recent International Conference on Alzheimer’s Disease (ICAD) in Vienna suggests several promising ways to answer “yes.” The findings add to a growing body of evidence that lifestyle changes—exercise, diet, even how much alcohol you drink—can help prevent or slow the mental decline that too often comes with aging.

“We can’t do anything about aging or family history, but research continues to show us that there are lifestyle decisions we all can make to keep our brains healthier, and that also may lower our risk of memory decline as we age,” said William Thies, PhD, chief medical and scientific officer at the Alzheimer’s Association, which sponsored the conference.

Here’s a look at this cutting-edge research and what it means to you:

Get moving: As if you needed yet another reason to get up off the couch and get moving, research presented at ICAD reports that activity such as walking 20 to 30 minutes a day, in addition to benefiting your body, may help protect your aging brain. Deborah E. Barnes, PhD, MPH, of the University of California-San Francisco, and colleagues found that even intermittent activity such as walking is associated with a lower rate of cognitive decline compared to sedentary seniors.

“We found that older adults who were sedentary throughout the study had the lowest levels of cognitive function at the beginning and experienced the fastest rate of cognitive decline,” Barnes said. “Cognitive decline also was faster in those whose physical activity levels consistently declined during the study period.”

The researchers studied 3,075 men and women in their 70s enrolled in the Health, Aging and Body Composition Study for an average of seven years. Self-reported walking times were compared with global cognitive scores on the Modified Mini Mental State Examination, a widely used screening test for dementia. Participants were classified as sedentary (0 minutes per week), low (less than 150 minutes per week) or high (150 minutes per week or more) in activity at the study’s start, then tracked for changes in activity.

Cognitive scores for the most-active seniors who were consistently active declined 0.40 points a year, versus 0.62 points for consistently sedentary subjects. People whose activity levels fluctuated still benefited from walking whenever they could, with an annual decline rate of only 0.44 points.

“They, so to speak, fall off the activity wagon,” Barnes said, “but our work shows they can get back on the wagon without losing a lot.”

“What we have learned from this trial study is that physical activity is important for older individuals,” Thies commented. “It doesn’t mean you have to go to the gym and work out—unless you want to do that. It just means getting more activity—as simple as walking to your neighborhood restaurant instead of driving there.”

DASH your diet: The Dietary Approaches to Stop Hypertension (DASH) eating plan, developed to fight high blood pressure, may also benefit your brain, according to another study presented at ICAD. Heidi Wengreen, PhD, RD, of Utah State University, and colleagues reported that people who most closely followed the DASH plan showed less cognitive decline.

The DASH regimen is high in fruits, vegetables and grains, while cutting back on meat, saturated fat, sweets and salt. (For details on DASH and how it compares to other dietary guidelines, see this issue’s Special Report.) None of the 3,831 participants in the Cache County (Utah) Study on Memory, Health and Aging was actually able to stick to the DASH plan 100%. But those who came the closest also kept their brains the sharpest.

“Our results suggest that including whole grains, vegetables, low-fat dairy foods and nuts in one’s diet may offer benefits for cognition in late life,” Wengreen said. “However, we need more research before we can confidently say how much of these foods to include in your diet to experience some benefit.”

While cautioning that their observational study can’t prove cause and effect, Utah State researcher Ron Munger, PhD, added, “Over the years, researchers have tried to slow cognitive decline using single nutrients and supplements, with mixed results. We believe that what we have observed is that the total DASH-like diet is greater than the sum of its parts.”

Participants were divided into five groups, ranked by how closely their diet matched the DASH goals. Tested using the Modified Mini Mental State Examination, those in the top group scored 1.72 points higher at baseline and 3.73 points higher after 11 years than those in the least-DASH-adherent group.

Maria Carrillo, PhD, director of medical and scientific relations at the Alzheimer’s Asso - ciation, commented, “Following the DASH diet helps you to preserve a little bit of cognitive function that otherwise would have been lost. The cognitive decline is cumulative, so ultimately there can be a big difference.”

Drink only a little: One or two alcoholic drinks a day—but no more—may reduce the risk of dementia, according to a third study presented at ICAD. Kaycee Sink, MD, of Wake Forest University, and colleagues reported that people who consumed one to two alcoholic beverages daily were less likely to develop dementia than teetotalers.

Dr. Sink and colleagues analyzed data on 3,069 participants in the Gink - go Evaluation of Memory Study, ages 75 and up, who’d undergone a complete cognitive assessment. Over an average of about six years, 576 cases of dementia were diagnosed among the 2,587 people originally assessed as normal, plus 188 cases among those with mild cognitive impairment at the start.

At the five-year mark, moderate drinkers among the normal participants were 37% less likely to develop dementia than their abstaining peers. Those teetotalers were actually at greatest risk of developing dementia. Among participants already with mild cognitive impairment at the study’s start, however, heavy drinkers—more than two drinks a day—were nearly twice as likely as teetotalers to progress to dementia.

Dr. Sink cautioned that despite her findings, she wouldn’t recommend that anyone start drinking alcoholic beverages in hopes of warding off dementia. And Carillo of the Alzheimer’s Asso - ciation pointed out that alcohol itself may not be protective; instead, moderate drinking may reflect an overall lifestyle linked to lower risk.

TO LEARN MORE: Alzheimer’s Association, (800) 272- 3900,www.alz.org