If you've been noticing your thinking skills are slipping, the results of a new study offer some hopeful news. Adding exercise can thwart age-related cognitive decline — and the changes can be felt in as little as six months’ time.
“The results are encouraging in that in just six months, by adding regular exercise to 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, in a statement.
One hundred sixty seniors, average age 65, took part in the study. All had risk factors for heart disease like high blood pressure and had reported cognitive problems, but none had full-blown dementia.
The participants were split into four groups: One group added aerobic exercise (cardio) to their routines three times a week; each 45-minute session included 10 minutes of warm-up and 35 minutes of aerobics (walking, jogging or cycling on a stationary bicycle).
The second group of participants switched to eating the Dietary Approaches to Stop Hypertension (DASH) diet. As the name suggests, the DASH diet was developed as a low-salt dietary intervention for people with high blood pressure. It is rich in fruits and veggies, whole grains, beans, nuts, low fat dairy products, whole grains and lean meat.
At the beginning of the study, their impaired thinking skills were what you’d expect to see in 93-year-olds — 28 years greater than their average chronological age.
The third group added both exercise and the DASH diet; and the final group just received health information via phone calls every week or two. The participants all had their thinking and memory skills assessed at the beginning of the study and again after six months.
It turned out that those who took part in both the exercise and diet interventions showed the greatest improvement over the six months. Those who’d done exercise alone also improved, while those who only switched to the DASH diet did not, which suggests much of the effect may come from the aerobics. The participants who received health education showed a small decline over the six months.
To put these memory gains in a more concrete way, Blumenthal explained that at the beginning of the study, the somewhat impaired participants' scores for select subtests of executive function corresponded to those of people who were biologically 93 years old — 28 years older than their actual chronological age. After six months, however, the average executive function scores of those seniors who exercised and followed the DASH diet corresponded to those of people who were biologically age 84, a nine-year improvement. And it’s possible their performance would improve further with more time — and continued exercise.
The researchers do caution that the study was relatively small and a larger group of participants would be needed to draw firmer conclusions about one intervention being more effective than others. “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,” Blumenthal said.
Other research has also suggested that about this amount of exercise — two hours per week — has measurable effects on thinking skills in seniors. And other studies have linked diet — both DASH and the mind-friendly MIND Diet — to cognitive health.
Talk to your doctor before beginning an exercise regimen or making a big dietary change, especially if you’re at risk of heart disease. But the study adds to the growing body of evidence that lifestyle really does affect not just our bodies, but also our minds.
The study was carried out by a team at Duke University and published in Neurology®, the medical journal of the American Academy of Neurology.