In one of the first extensive, long-term studies to look at heart disease risk factors in young adults, researchers have found that elevated heart risks are linked with lower cognitive function in mid-life.
Other studies have previously linked heart disease risk factors in mid- and late-life to cognitive function, but little has been known about exposure to these risk factors in early adulthood.
The researchers, led by Dr. Kristine Yaffe of the University of California-San Francsico, published their research in the American Heart Association (AHA) journal Circulation.
"It's amazing that as a young adult, mildly elevated cardiovascular risks seem to matter for your brain health later in life," says Dr. Yaffe. "We're not talking about old age issues, but lifelong issues."
According to the AHA, blood pressure should be less than 120/80 mmHg, while fasting glucose should be less than 100 mg/dL and total cholesterol should be less than 200 mg/dL.
Additionally, the organization has specific guidelines on total LDL "bad" cholesterol, depending on the individual:
- Low risk for heart disease: less than 160 mg/dL
- Intermediate risk for heart disease: less than 130 mg/dL
- High risk, including those with heart disease or diabetes: less than 100 mg/dL
- Very high risk for heart disease: less than 70 mg/dL.
Those with higher heart risk factors in youth scored lower on cognitive tests later
Young adults with certain heart risk factors, such as blood pressure over 120/80 mmHg, scored lower on cognitive tests in their 40s or 50s.
The researchers say their study, which was part of the ongoing multi-center Coronary Artery Risk Development in Young Adults (CARDIA) Study, lasted for 25 years and followed 3,381 people between the ages of 18 and 30 years old.
Every 2 to 5 years, the researchers checked the participants' blood pressure, fasting blood sugar and cholesterol levels.
They then assessed each individual's cumulative cardiovascular health during this time, and at the end of the study period, the participants took three tests that measured memory, thinking speed and mental flexibility.
Those who had high blood pressure, blood sugar and cholesterol levels in their young adult life scored lower on the cognitive function tests in their 40s and 50s, the researchers found.
In detail, standardized scores on the tests were between 0.06 and 0.30 points less for every standard deviation (or variation from the average) increase in total exposure to these risk factors. The researchers say this is a significant finding for this age group.
Findings could have implications for Alzheimer's disease
Fast facts about how to stay heart healthy
- Consume less than 1,500 mg of sodium each day.
- Get at least 30 minutes of exercise a day, 5 days a week.
- Do not smoke.
- Keep body mass index (BMI) at less than 25 kg/m2.
- Have five or more servings of fruit and veg a day.
The team explains that high blood pressure, blood sugar and cholesterol are main risk factors for atherosclerosis, which is when the arteries narrow due to plaque building up in the artery walls that lead to the brain and heart.
Dr. Yaffe says this narrowing of the arteries leading to and in the brain is the most likely reason for why heart health and cognitive function are linked.
"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 emphasizing the importance of controlling risk factors among younger people," she adds.
In the conclusion to their study, the study authors say more research is needed to understand this association and whether it merits more targeted treatment of cardiovascular risk factors earlier in life.
Medical News Today recently reported on a study that suggested daylight saving time may accelerate cardiac events in some individuals, citing a 25% increase in the number of heart attacks on the first Monday after the clocks roll forward.