People who have a fit and healthy body at the age of 40 may be able to retain more brain volume when they hit 60, reveals a new study.
In individuals with low fitness levels, the blood pressure and heart rate responses to low levels of exercise are often much higher than in individuals with better fitness.
The researchers found that people who had a lower fitness level or greater increase in diastolic blood pressure (bottom number) or heart rate a few minutes into the low-intensity treadmill test (2.5 miles an hour) had smaller brain tissue volume later in life.
People who had a larger increase in diastolic blood pressure during low-intensity exercise also performed more poorly on a cognitive test for decision-making function later in life.
Poor physical fitness could be associated with accelerated brain aging.
Apart from the exercise tests, a higher resting systolic blood pressure (top number) at age 40 was associated with a smaller frontal lobe volume and a greater volume of white matter hyperintensity (an indicator of loss of blood flow with aging) on the later brain MRIs.
Promotion of midlife physical fitness might be an important step towards ensuring healthy aging of the brain in the population.