Want to slow down the aging process of your brain? Well, then start keeping you heart healthy, suggests a new study.
In the study, people whose hearts pumped less blood had brains that appeared older than the brains of those whose hearts pumped more blood.
Decreased cardiac index, the amount of blood that pumps from the heart in relation to a person's body size, was associated with decreased brain volume using magnetic resonance imaging (MRI).
Researchers observed the link even in those participants who did not have cardiovascular disease, such as heart failure or coronary heart disease. As the brain ages, it begins to atrophy (shrink) and has less volume.
The decrease in brain volume is considered a sign of brain aging. More severe brain atrophy occurs in those with dementia, such as Alzheimer's disease.
"The results are interesting in that they suggest cardiac index and brain health are related," said Angela L. Jefferson, the study's lead author and associate professor of neurology at the Boston University School of Medicine.
"The association cannot be attributed to cardiovascular disease because the relationship also was seen when we removed those participants with known cardiovascular disease from our analyses," Jefferson added.
In the observational study, which cannot establish cause and effect, researchers examined brain and heart MRI information on 1,504 participants of the decades-long Framingham Offspring Cohort who did not have a history of stroke, transient ischemic attack or dementia. Participants were 34 to 84 years old and 54 percent were women.
Researchers measured cardiac output using MRI and normalized the data for each participant's body surface area. Brain volume was assessed using MRI. Participants were divided into three groups based on cardiac index values.
The participants who had the lowest cardiac index, or the least amount of blood pumping from the heart for their body size, showed almost two years more brain aging than the people with the highest cardiac index.
The participants in the middle cardiac index group, who had low but still normal levels of blood pumping from the heart, also showed almost two years more brain aging than the people with the highest (or healthiest) cardiac index.
"We expected an association between the lowest levels of cardiac index and smaller brain volumes, but we were surprised to find people on the lower end of normal cardiac index also have smaller brain volumes when compared to people with very health cardiac index," Jefferson said.
The study has been reported in Circulation: Journal of the American Heart Association.