"Isn't dementia just an unavoidable part of getting old?" Many people in their 50s ask themselves this question as they notice their memory is not what it used to be. But a new study suggests there is no need to start with an elaborate health regimen to lower the risk of dementia. Keeping just three factors in check during middle age can extend the time a person lives free of dementia by nearly 13 years, the analysis found.
Living Without 3 Risk Factors Extends Dementia-Free Life by 12.6 Years
Researchers at NYU Langone Health recently tracked 12,409 U.S. adults with an average age of 56 over an average of 26 years, analyzing how three risk factors — high blood pressure, diabetes and smoking — affect dementia.
People who did not smoke and had neither high blood pressure nor diabetes lived free of dementia for an average of 12.6 years longer than those with all three risk factors.
Measured from the start of the study, people with none of the risk factors lived dementia-free for an average of 30.1 years, compared with just 17.5 years for those with all three. During the follow-up period, 3,008 participants developed dementia and 5,238 died without developing it.
People with all three risk factors were also about 2.7 times more likely to develop dementia than those with none.
The researchers focused on these three factors because all can be controlled to some degree through daily life. Smoking, high blood pressure and high blood sugar can damage blood vessels and cause inflammation, raising the risk of cerebrovascular disease and dementia.
Notably, the toxic proteins known to cause Alzheimer's disease begin building up in the brain about 15 to 20 years before symptoms appear. Given that dementia mostly emerges after age 65, this means management is important starting from one's late 40s or 50s.
Cutting Even One Factor Delays Dementia by About 4 Years
Even if managing all three at once is difficult, improving just one or two made a difference.
Compared with people who had all three risk factors, cutting one factor was associated with delaying the onset of dementia by about four years, and cutting two by about eight years.
The difference at age 85 was also large. Among those with all three risk factors, only 7% remained free of dementia, while 35% of those with none lived without it.
There were also differences by sex. Even among those with all three risk factors, women lived dementia-free for an average of 18.1 years after the start of the study, longer than the 16.6 years for men.
However, the study did not prove a causal relationship in which managing blood pressure, diabetes and smoking directly delays the onset of dementia. It confirmed an association in which people with fewer of the three risk factors showed a longer dementia-free period.
What to Do From Your 50s Is Surprisingly Simple: "Exercise and Cut Sugar"
So what should people do from middle age? The methods the researchers emphasized are nothing special.
Joseph Coresh, the NYU professor who led the study, stressed quitting smoking along with regularly checking and managing blood pressure and blood sugar. He explained that exercising regularly and cutting excessive sugar intake are especially important to prevent diabetes and high blood pressure.
This does not mean people must seek out difficult brain training or special health foods starting in their 50s to prevent dementia. Rather, basic lifestyle habits — checking your blood pressure regularly, managing your diet and exercise to keep blood sugar from rising, and quitting smoking — can be linked to brain health decades later.
"Actively managing these risk factors during middle age alone may make it possible to secure more than 10 additional years of healthy life free from the risk of dementia and death," Coresh said.
The study did not analyze other risk factors related to dementia, such as hearing loss, social isolation and air pollution. It also measured vascular risk factors at a single point in time, so it does not reflect how lifestyle or health status changed afterward.
