Memory loss and worsening thinking skills in middle age have been linked to heart health, researchers have found.
A new study has reported that small changes in the heart could be a risk factor for cognitive decline in middle age.
Risk markers for lower thinking and memory skills in middle age could appear in the heart before heart disease even occurs, the study concluded.
Heart health risks like high blood pressure, high cholesterol and diabetes have already been linked with an increased risk of cognitive impairment.
However, much less was known specifically about changes in heart structure and heart function in relation to mental processes and ability.
The study was published in Neurology , the medical journal of the American Academy of Neurology, on January 26.
Experts followed young adults over a 25 year period through middle age and found declines in thinking and memory skills associated with heart structure and function.
"Our findings are of critical importance in the context of identifying potential early markers in the heart of increased risk for later-life cognitive decline," said study author Laure Rouch, PharmD, PhD, of the University of California, San Francisco.
"Such abnormalities are common and often underdiagnosed as they do not produce any obvious symptoms."
The researchers analysed a group of 2,653 people with an average age of 30 over 25 years.
Participants had echocardiograms - ultrasound images of the heart - performed at the start of the study, then after 20 and 25 years.
In the final year of the study, participants' thinking and memory skills were measured by six cognitive tests, including a test that included remembering words from a list they had viewed 10 minutes before.
Researchers found a link between the weight of a person's left ventricle and their left atrial volume to lower cognition in middle age on most tests.
The conclusion was true even when taking into account other heart health risks like high blood pressure, diabetes, smoking and obesity.
Dr Rouch said: "As early as young adulthood, even before the occurrence of cardiovascular disease, there may be heart abnormalities that could be risk markers for lower thinking and memory skills in middle age.
"In the future, a single echocardiogram may help identify people at higher risk of cognitive impairment."
The lead author said further research should look into whether taking action to improve the structure and function of the heart could benefit brain health.
