Hypertension, diabetes, smoking: three risk factors between ages 45-65 that can delay dementia

A new study shows that three health-related factors present in middle age can delay the onset of dementia by more than a decade. Researchers found that maintaining normal blood pressure, avoiding type 2 diabetes, and giving up smoking between the ages of 45 and 65 are associated, on average, with nearly 13 additional years of dementia-free life. The findings were published in the medical journal Neurology, according to News.ro.

The study also found that, regardless of how many risk factors a person had, women live longer without dementia than men, and white individuals have more dementia-free years than Black individuals.

How the study was conducted

Researchers at NYU Langone Health used data from the Atherosclerosis Risk in Communities (ARIC) project, launched in 1986, which tracked a group of Americans over several decades, measuring their vascular risk factors and the incidence of dementia in middle age.

For the new analysis, 12,409 individuals were studied, with a mean age of 56, who had no dementia at the time of enrolment. Participants were assessed according to three risk factors — high blood pressure, type 2 diabetes, and smoking — and then followed for approximately three decades (with a mean follow-up period of 26 years).

During the study, 3,008 individuals developed dementia, and 5,238 died without developing the condition.

Differences in dementia-free years according to risk factors

People with none of the three risk factors lived without dementia for nearly 13 years longer, on average, than those who had all three.

• No risk factors (no diabetes, no high blood pressure, non-smokers): 30.1 additional dementia-free years on average
• One risk factor: 26.3 years
• Two risk factors: 21 years
• All three risk factors: just over 17 years

"Our findings suggest that people need to actively avoid these factors in middle age as a strategy for maintaining brain health for more than a decade," said Dr Josef Coresh, the study's lead researcher and Director of the Institute for Excellence in Health Equity at NYU Langone.

"We hope these results will encourage people to quit smoking and to carefully monitor their vascular health from the age of 45," he added.

The global context of dementia

The number of people living with dementia worldwide is estimated to nearly triple, reaching 153 million by 2050. However, experts believe that almost half of all dementia cases globally could be prevented or delayed.

Previous research has shown that addressing 14 modifiable risk factors — beginning in childhood and continuing throughout life — could prevent or delay 45% of dementia cases, even as people live longer.