December 1 (HealthDay News) -- Older adults who exercise regularly have increased blood flow and more small blood vessels in the brain, a new study shows.

The University of North Carolina (UNC) study, expected to be presented Monday at the Radiological Society of North America (RSNA) annual meeting, in Chicago, may help explain other studies that exercise prevents cognitive decline in the elderly.

"These findings further point out the importance of regular exercise to healthy aging," study senior author Dr. J. Keith Smith, an associate professor of radiology at the UNC School of Medicine, said in a news release issued by the RSNA.

The researchers did MRIs and MR angiography on a dozen healthy adults, aged 60 to 76, half of whom did aerobic exercise for three or more hours a week over the past decade, while the other half exercised less than one hour a week.

SOURCE: Radiological Society of North America, news release, Dec. 1, 2008