February 28, 2019
Older men and women with thinking and memory problems showed improvements in cognitive skills after six months of moderate exercise, a new study found. The exercise did not need to be rigorous, but it did need to be aerobic — that is, it needed to raise the heart rate moderately.
None of those in the study had Alzheimer’s disease or other forms of dementia. But they did have problems like poor concentration or difficulty making decisions or remembering things.
After six months, the men and women who exercised had higher scores on tests of executive function, which is a person’s ability to regulate their own behavior, pay attention, organize and manage time and space, and achieve goals. People with poor executive function are at increased risk of developing full-blown dementia.
“The results are encouraging in that in just six months, by adding regular exercise into their lives, people who have cognitive impairments without dementia may improve their ability to plan and complete certain cognitive tasks,” said study author James A. Blumenthal of Duke University Medical Center. The findings appeared in Neurology, the medical journal of the American Academy of Neurology.
For the study, researchers enrolled 160 men and women whose average age was 65. They all reported problems with memory and thinking skills, though the problems were not serious enough to qualify for a diagnosis of Alzheimer’s disease or dementia. They also all had risk factors for heart disease, such as high blood pressure, and none of them exercised on a regular basis.
Participants were randomly assigned into one of four groups. Some entered an exercise program, in which they did a 10-minute exercise warm-up, followed by aerobic exercises like walking or cycling for 35 minutes three times a week.
A second group followed a DASH diet, for Dietary Approaches to Stop Hypertension, a heart-healthy diet that was designed specifically for people with high blood pressure. The DASH diet is a low-sodium, high fiber diet rich in fruits and vegetables, beans, nuts, low fat dairy products, whole grains, and lean meats.
A third group exercised and also followed the DASH diet.
The fourth group, which served as controls, got routine care and educational phone calls every one to two weeks.
After six months, those who exercised, including those who exercised and followed a DASH diet, showed improvements in executive function. Those who both exercised and ate a heart-healthy diet showed the greatest improvements.
Those who followed a DASH diet only did not show improvements in thinking skills, and those who served as controls continued to worsen.
“More research is still needed with larger samples, over longer periods of time to examine whether improvements to thinking abilities continue and if those improvements may be best achieved through multiple lifestyle approaches like exercise and diet,” Dr. Blumenthal said.
But the findings add to a growing body of evidence that regular exercise, which is known to be good for the heart, may also be good for the brain. Although the heart-healthy DASH diet alone did not produce benefits in this study, other studies suggest that a DASH, along with weight loss, can have beneficial effects for brain health. A Mediterranean-style diet, high in fruits and vegetables and heart-healthy fats like olive oil, has also been shown to be good for the brain.
“Growing evidence supports the value of multicomponent interventions in mitigating cognitive decline,” the authors wrote. In one earlier study, for example, adherence to a Mediterranean-type diet and higher physical activity were associated with reduced risk for dementia. Other reviews of data “have suggested that exercise programs that are supplemented by additional interventions confer larger cognitive benefits compared to interventions using exercise alone,” the authors conclude.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: James A. Blumenthal, PhD, Patrick J. Smith, PhD, Stephanie Mabe, MS, et al:
“Lifestyle and neurocognition in older adults with cognitive impairments A randomized trial.” Neurology, Dec. 2018