Heart health Using magnetic resonance imaging (MRI), researchers from the Boston University School of Medicine in the USA found that people whose hearts were not as efficient at pumping blood around the body had older-looking brains than those who had healthier tickers.
Brain shrinkage itself is normal – everyone’s brain volume decreases to some degree as they age - but the researchers found that your heart also plays a part, potentially making a brain age prematurely.
By measuring study participants’ cardiac index, which is the volume of blood that the heart pumps through the body in relation to the person’s body size, researchers were able to assess whether a smaller volume of blood was linked to any changes in the brain.
What they found, according to their report published in Circulation: Journal of the American Heart Association, was that with a smaller volume of blood, brain volume also decreased. Those who had the smallest volume of blood being pumped around for their size showed the equivalent of two years' added ageing on their brains, when compared to those who had the highest blood volume.
Interestingly, even those in the middle – those who had a normal cardiac index – showed two years' more ageing than those in the high cardiac index group. These effects were seen both in individuals who also had other heart problems, such as coronary heart disease, but also in people who showed no signs of heart disease (only 7% of study participants had heart disease).
The exact cause for a link between heart function and brain volume is still not well understood, said Angela L Jefferson, the study's lead author and associate professor of neurology at the Boston University School of Medicine: "There are several theories for why reduced cardiac index might affect brain health. For instance, a lower volume of blood pumping from the heart might reduce blood flow to the brain, providing less oxygen and fewer nutrients needed for brain cells. It is too early to dole out health advice based on this one finding but it does suggest that heart and brain health go hand in hand."
First published August 4, 2010.