Exercising to improve cardiovascular health could also benefit the brain.
Age-related blood vessel stiffening is believed to begin in the aorta (the main vessel coming from the heart) before reaching the brain, the University of Montreal reported. These changes are believed to contribute to cognitive changes that occur around the same time.
"We found that older adults whose aortas were in a better condition and who had greater aerobic fitness performed better on a cognitive test. We therefore think that the preservation of vessel elasticity may be one of the mechanisms that enables exercise to slow cognitive aging," said Claudine Gauthier, first author of the study.
The team looked at 31 young people between the ages of 18 and 30 and 54 and participants between 55 and 75. The researchers exhausted the participants on an exercise machine and determined their maximum oxygen intake over a 30 second period. Their cognitive abilities were also tested using the Stroop task.
The participants underwent three MRI scans: one to see blood flow to the brain; one to assess brain activity during the Stroop task; and one that looked at the physical state of the aorta.
"This is first study to use MRI to examine participants in this way," Gauthier said. "It enabled us to find even subtle effects in this healthy population, which suggests that other researchers could adapt our test to study vascular-cognitive associations within less healthy and clinical populations."
The results reveal age-related declines in "executive function, aortic elasticity and cardiorespiratory fitness," and a link between vascular health and brain function.
"The link between fitness and brain function may be mediated through preserved cerebrovascular reactivity in periventricular watershed areas that are also associated with cardiorespiratory fitness," Gauthier said. "Although the impact of fitness on cerebral vasculature may however involve other, more complex mechanisms, overall these results support the hypothesis that lifestyle helps maintain the elasticity of arteries, thereby preventing downstream cerebrovascular damage and resulting in preserved cognitive abilities in later life."
