The finding that women had greater brain volume losses while men had worse mental function at the time of Alzheimer's diagnosis is also hard to explain, Wright said: "One would expect greater atrophy in those with worse cognition unless additional factors such as vascular damage explained these differences."
In a related presentation Monday, researchers from University of California, Los Angeles reported that leading an active lifestyle may help halt brain aging and preserve gray matter volume even among people who already have evidence of dementia.
The study included 876 adults with an average age of 78. Individuals' mental function ranged from normal to Alzheimer's dementia. Researchers used MRI brain scans and a technique called voxel-based morphometry to see how physical activity affects gray matter volume. This technique allows a computer to analyze a brain scan and build a mathematical model that helps researchers understand the relationship between active lifestyle and gray matter volume.
Study participants who burned more calories via recreational sports, gardening and yard work, bicycling, dancing and riding an exercise cycle lost less gray matter in key areas of their brains. This was true even among those with evidence of mental decline. The finding held even after the team controlled for other factors known to influence brain volume including head size, mental impairment, gender, body weight, education and white matter disease.
Exercise likely improves blood flow to the brain, and strengthens the connections between brain cells, the study authors concluded.
Because these studies were presented at a medical meeting, the data and conclusions should be viewed as p
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