Lead author Hui-Xin Wang surveyed 506 individuals over the age of 78, none of whom were suffering from dementia at the onset of the study. One set of survey questions focused on personality, and sorted the participants according to various traits. Some individuals were extraverted and tended to be social and optimistic. Some were prone to distress and tended to be nervous, negative, and more often emotionally unstable. And some participants were more laid-back and calmer than others.The relaxed individuals had a 50% less likelihood of developing dementia than the distressed participants.
Another set of survey questions centered on lifestyle, assessing whether participants were more involved in social activities, or tended to be more isolated and favored at-home activities.
Wang and her team followed the group for six years, over which period 144 participants developed some form of dementia. They found that among the socially inactive, those who were relaxed had a 50% less likelihood of developing the disease than did people who were prone to distress. In the outgoing group, the results were the same: the relaxed individuals had a 50% less likelihood of developing dementia than the distressed participants.
The author points out that it is possible that having both of the traits associated with lower risk — that is, being outgoing and relaxed — may work in concert to further decrease the risk of dementia. She also suggests a possible neural mechanism for her findings, citing previous research that found that chronic distress can affect certain areas of the brain. One of the areas known to be affected is the hippocampus, an important player in memory and a known victim of Alzheimer's disease.
"The good news is, lifestyle factors can be modified as opposed to genetic factors which cannot be controlled. But these are early results, so how exactly mental attitude influences risk for dementia is not clear, " Wang notes.
