Physical activity can preserve memory in the brains of the elderly.

A group of 120 older adults were randomly assigned between two groups: the first group had three moderate aerobic workouts a week, and the second group only stretched for the same amount of time. MRI imaging and memory tests were done at the beginning, after 6 months and after 1 year. Those who only stretched showed a 1.4% decline in brain volume (the hippocampus), while the brain volume of those who moderately exercised actually increased more than 2%. Both groups had memory improvement, but the group doing aerobic exercise showed more.

PositiveTip: Moderate aerobic exercise is a pretty cheap and easy-to-implement intervention to preserve brain function.

People with more abdominal fat have smaller total brain volume.

Could it really be related? Midlife obesity has long been associated with increased risk of dementia, although the how the relationship works has been poorly understood. 

Researchers examined possible associations between cerebral brain volume and obesity in 733 middle age community adults. They found a significant association between visceral (abdominal) fat and low total brain volume. The authors suggest that inflammation resulting from fat cells may negatively impact brain tissue.