Physical activity in older adults linked to brain white-matter integrity

September 17, 2014
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Science Daily/University of Illinois at Urbana-Champaign
Like everything else in the body, the white-matter fibers that allow communication between brain regions also decline with age. 

In a new study, researchers found a strong association between the structural integrity of these white-matter tracts and an older person's level of daily activity -- not just the degree to which he or she engaged in moderate or vigorous exercise, but also whether the person was sedentary the rest of the time.

"This relationship between the integrity of tracts connecting the hippocampus and sedentariness is significant even when we control for age, gender and aerobic fitness," she said. "It suggests that the physiological effect of sitting too much, even if you still exercise at the end of the day for half an hour, will have a detrimental effect on your brain."

The findings suggest that engaging in physical activity and avoiding a sedentary lifestyle are both important for brain health in older age, Burzynska said. "We hope that this will encourage people to take better care of their brains by being more active," she said.

The team found that the brains of older adults who regularly engaged in moderate-to-vigorous exercise generally "showed less of the white-matter lesions," Burzynska said.

The association between physical activity and white-matter structural integrity was region-specific, the researchers reported. Older adults who engaged more often in light physical activity had greater structural integrity in the white-matter tracts of the temporal lobes, which lie behind the ears and play a key role in memory, language, and the processing of visual and auditory information.

In contrast, those who spent more time sitting had lower structural integrity in the white-matter tracts connecting the hippocampus, "a structure crucial for learning and memory," Burzynska said.

"This relationship between the integrity of tracts connecting the hippocampus and sedentariness is significant even when we control for age, gender and aerobic fitness," she said. "It suggests that the physiological effect of sitting too much, even if you still exercise at the end of the day for half an hour, will have a detrimental effect on your brain."
Science Daily/SOURCE :http://www.sciencedaily.com/releases/2014/09/140917141429.htm