August 3, 2010
By Susan Brady

While many believe keeping the brain active is the key to keeping it from going to mush, that isn’t the only thing that is a contributing factor. There is now a direct link between a healthy heart and a healthy active brain.

Research conducted by a team from Boston University and published in this week’s issue of Circulation, showed that blood volume had a correlation to the size and activity of the brain. Studying approximately 1,500 mostly heart-healthy individuals (substantial cardiovascular issues precluded inclusion in this study), researchers found that those hearts that pumped less blood were associated with brains that appeared older and smaller in size. Even those individuals with a normal cardiac index and blood volume showed signs of early aging in brain scans.

Lead researcher Dr Angela Jefferson said: “These participants are not sick people. A very small number have heart disease. The observation that nearly a third of the entire sample has low cardiac index and that lower cardiac index is related to smaller brain volume is concerning and requires further study.”

While the average age of participants was 61, even the younger members of the study showed a link between reduced blood volume and an older, smaller brain. Poor cardiac output aged the brain by nearly two years on average, according to researchers. However, the researchers did note that participants with smaller brain volumes on magnetic resonance imaging did not show obvious clinical signs of reduced brain function. This may mean that reduced blood volume and reduced brain volume may be early signs that something could or will go awry in the future.

Brain shrinkage, particularly in the hippocampus, is associated with dementia.There are other causes of brain shrinkage, such as the use of hormone replacement therapy [1]. Current studies show that hormone therapy is linked to brain shrinkage, but not the small brain lesions which are usually the first signs of cerebrovascular disease. Low levels, as well as severe deficiencies, of vitamin B12 [2] also contribute to brain atrophy. And studies have shown that obesity can age the brain and reduce brain tissue [3].