People taking part in the study were assessed for high blood pressure, diabetes and smokingAvoiding three things in middle age is linked to 13 more years without dementia, experts have said. Having normal blood pressure, no diabetes and not smoking from age 45 to 65 keeps dementia at bay for well over a decade, research suggests. A team from NYU Langone Health in the US studied more than 12,000 people to examine three key things affecting dementia risk. People were assessed for high blood pressure, diabetes and smoking, and followed for an average of 26 years. Those who had none of the three risk factors lived without developing dementia nearly 13 years longer than those who had all three.