MRA explains benefits of exercise for aging adults

December 1, 2008

Doctors have known for years that aerobic exercise counteracts the effects of aging on the human brain. Findings presented at the RSNA meeting contributed to an explanation of why.

Doctors have known for years that aerobic exercise counteracts the effects of aging on the human brain. Findings presented at the RSNA meeting contributed to an explanation of why.

A study conducted at the University of North Carolina is the first to compare brain scans of older adults who exercise with those of older adults who do not. It looked at 12 healthy adults, aged 60 to 67, using MR technology to determine cerebral blood flow and MR angiography to depict blood vessels in the brain.

"Our theory was that [the positive effect of exercise] is due to the effect on the blood flow and the vasculature," said presenter Feraz Rahman, a medical student at Thomas Jefferson University Medical College.

Exercise causes an increase in vessel size and number, improving blood flow, Rahman said.

The study used a method of 3D computer reconstruction developed in the researchers lab to create a 3D model of the blood vessels in their subjects. They were then able to examine the vessels for shape and size.

"The first goal of our study was to see if these differences [between active and inactive groups] are dependent on some underlying vessel differences. Our second goal was to test the hypothesis that older adults who engage in exercise have more blood vessels, focusing on the smaller ones," Rahman said.

The researchers found that there were, in fact, differences in the vessels. Active adults have significantly more small blood vessels and an improved cerebral blood flow, according to the study.

"These findings further point out the importance of regular exercise to healthy aging," said senior author Dr. J. Keith Smith.