People who avoided high blood pressure, diabetes and smoking during middle age lived nearly 13 years longer without dementia than people with all three risk factors.
Researchers followed more than 12,000 adults for an average of 26 years, suggesting that protecting cardiovascular health in middle age may also protect the brain decades later.
The study found an association, not proof of cause and effect, but researchers say the findings strengthen the case for quitting smoking and controlling blood pressure and blood sugar well before old age.
What you do for your heart in middle age may have a surprisingly large impact on how long your brain remains healthy.
A new study led by researchers at NYU Langone Health found that adults who had normal blood pressure, did not have diabetes and did not smoke during middle age lived nearly 13 years longer without dementia, on average, than people who had all three risk factors.
The findings, published in Neurology Open Access, suggest that some of the most important steps consumers can take to reduce their risk of cardiovascular disease may also help postpone dementia.
"Our findings argue that people need to actively avert these factors in midlife as a strategy for preserving brain health for more than a decade," said senior investigator Dr. Josef Coresh, founding director of NYU Langone's Optimal Aging Institute.
Following people for decades
Researchers analyzed data from the Atherosclerosis Risk in Communities study, a long-running project that began in 1986.
The new analysis included 12,409 people who did not have dementia when they entered the study. Their average age was 56, and researchers assessed whether they had three major vascular risk factors: high blood pressure, diabetes and smoking.
Participants were then followed for an average of 26 years. During that period, 3,008 developed dementia, while 5,238 died without developing the condition.
The difference in dementia-free lifespan was significant.
Participants with none of the three risk factors lived an average of about 30 years after the beginning of the study without developing dementia. Those who had all three averaged only about 17 dementia-free years — a difference of nearly 13 years.
In other words, the findings suggest that the health consequences of smoking, hypertension and diabetes may extend well beyond heart attacks and strokes. The same conditions that damage blood vessels may also influence how long the brain remains healthy.
Differences among groups
Researchers also found differences based on sex and race.
Among people who had all three risk factors, women lived an average of 18.1 years without dementia after the start of tracking, compared with 16.6 years for men.
White participants with all three risk factors averaged 19.6 dementia-free years, compared with 16 years among Black participants. Researchers said the findings suggest that reducing vascular risks could benefit everyone but that targeted prevention efforts could be especially important for some populations.
What consumers can do
The study points to three potentially modifiable targets during middle age: don't smoke, keep blood pressure under control and prevent or properly manage diabetes.
That makes routine medical care potentially important for long-term brain health. High blood pressure, for example, can exist for years without obvious symptoms, making regular blood-pressure checks important. Likewise, blood tests can identify elevated glucose levels or prediabetes before Type 2 diabetes develops.
For smokers, quitting remains one of the most significant changes they can make to reduce cardiovascular risks.
The researchers caution, however, that the study does not prove that eliminating these three risk factors will give an individual an additional 13 dementia-free years. It was an observational study, meaning researchers identified an association rather than establishing cause and effect.
There was another limitation: the three risk factors were measured only once, so the study could not fully account for people whose health or smoking habits changed during the decades of follow-up.
The research adds to evidence connecting cardiovascular and brain health and suggests that dementia prevention may need to begin much earlier than many people assume.
For people in their 40s, 50s and 60s, taking care of the heart may turn out to be one of the better investments they can make in the health of their brain later in life.