A study following more than 12,000 people has found that avoiding three common health issues in middle age is linked to an average of 13 more years without dementia in later life. The research assessed participants for high blood pressure, diabetes, and smoking, then tracked them for an average of 26 years.
Key findings
During the follow-up period, 3,008 people developed dementia, and 5,238 died without developing dementia. Those who had none of the three risk factors lived an average of 13 more dementia-free survival years than those who had all three. From age 55, people without diabetes or high blood pressure who did not smoke could expect to live an average of 30.1 more years free of dementia, compared with just 17 years for those with all three risk factors.
Expert commentary
Senior investigator Dr Josef Coresh, director of the Optimal Aging Institute at NYU Langone, said: “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.” He added: “People with all three risk factors were more likely to develop dementia or die at earlier ages from other causes, leading to shorter overall survival and fewer years with their thinking and memory abilities intact.”
How these factors affect the brain
High blood pressure is thought to harm tiny blood vessels that supply the brain and can also cause silent mini-strokes, which damage brain cells. Diabetes increases the risk of dementia, possibly due to related health problems such as obesity, high blood pressure, and high cholesterol. Smoking increases the risk of vascular problems affecting the heart and blood vessels, and toxins in cigarette smoke cause inflammation and stress to cells, both linked to Alzheimer's disease, according to Alzheimer’s Society.
Gender differences and limitations
The study also found that women were likely to remain dementia-free for longer than men. Those with all three risk factors lived an average of 18.1 years without developing dementia, compared to 16.6 years for male participants. Researchers stressed the study was observational, so it could not prove that the absence of these risk factors caused the delay in dementia; it only showed an association.
Dr Coresh added: “Hopefully these results will help encourage people to stop smoking, manage their blood sugar and manage their blood pressure in midlife. Of course, other healthy habits such as eating better and being more active are also important.”
The findings were published in Neurology Open Access, a journal of the American Academy of Neurology.
