Young adults who fail to look after their heart health may have poorer mental functioning later in life, the results of a new study indicate.

The US study involved almost 4,000 young adults aged 18-30. Over a 25-year period, they had their blood pressure, cholesterol levels and fasting blood sugar levels checked every two to five years.

After 25 years, each participant underwent three cognitive function tests, which assessed memory, thinking speed and mental flexibility.

The study found that those with higher blood pressure, blood sugar levels and cholesterol levels in young adulthood scored lower in the cognitive tests when they reached their 40s and 50s.

"It's amazing that as a young adult, mildly elevated cardiovascular risks seem to matter for your brain health later in life. We're not talking about old age issues, but lifelong issues," commented Dr Kristine Yaffe of the University of California in San Francisco.

The scientists noted that higher blood pressure, blood sugar and cholesterol levels are three of the main risk factors for atherosclerosis (hardening of the arteries). They suggested that a hardening and narrowing of the arteries leading to the brain is the most likely cause for their findings.

"Our study is hopeful, because it tells us we could maybe make a dent in the risks of Alzheimer's and other forms of dementia by emphasising the importance of controlling risk factors among younger people," Dr Yaffe commened.

Details of these findings are published in the journal, Circulation.

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