Older people can dramatically improve brain function with just six months of aerobic exercise, a new study has found.
Thirty-five minutes of continuous cycling three days a week for six months was shown to shave years off the brain age of older people.
The study subjects were sedentary people of average age 65 years. Being sedentary, their cognitive function was already impaired, with a tested brain age of 93 years.
But after six months of the exercise program, combined with a good diet, their brain age was down to 84, a drop of nine years.
A control group, who did no exercise, suffered further cognitive deterioration, and tests showed their brains aged an additional six months.
The results of the randomised clinical trial "Lifestyle and neurocognition in older adults with cognitive impairments” were published in the journal Neurology.
The study enrolled 160 adults who had high blood pressure or other risks for cardiovascular disease, who never exercised and who had verified cognitive concerns such as difficulty making decisions, remembering or concentrating. Participants were an average age of 65, two-thirds female and equally divided between different nationalities. Anyone diagnosed with dementia or unable to exercise was excluded.
Before starting their assigned path, participants underwent a battery of cognitive tests, a treadmill stress assessment and a dietary analysis. In addition, their blood pressure, blood sugar and lipids were recorded. The tests were repeated at the conclusion of the study.
Researchers randomly divided participants into four groups for the six-month study. One group started on a widely respected heart-healthy diet that cuts salt, fatty foods and sweets while emphasising vegetables, fruits and whole grains. A second group exercised but was not encouraged to diet. The third group did both. The fourth group was told not to change their diet and exercise habits.
The group who only exercised saw significantly greater improvements in their executive functioning skills than the group who did no exercise.
Researchers said the results showed that controlled aerobic activity within a very short period of time can have a significant impact on the part of the brain that keeps people taking care of themselves, paying their bills and the like.
Not only can you improve, but you can improve within six months.
Lead author Dr James Blumenthal said: "Remember, these are older adults who are completely sedentary and have verified cognitive impairments. We had no dropouts, and everyone was able to sustain the exercise program and do it on their own. That was great."
The group who followed the diet with no exercise didn't show a statistically significant improvement in thinking skills.
However, it was the group who combined exercise and diet who saw the greatest benefit.
Because those who combined diet and exercise saw the greatest improvements, it may be that multiple lifestyle changes, not just diet and exercise, are needed to maximize success, Blumenthal said.
What's important, he said, is that "adopting a healthy lifestyle can improve your risk, improve neurocognitive functioning, and it's not too late to start. Even in older people with some indication that their brains are compromised, they also benefit as well."