March 9, 2009
People who are socially engaged and can easily brush off stress may be at reduced risk for Alzheimer's, a new study reports. The study adds to a growing body of research linking lifestyle and personality traits to a lower chance of developing dementia in old age.
The research, from doctors at the Karolinska Institute in Sweden, found that older men and women who were easygoing and had active social lives were less likely to develop Alzheimer's disease than those who were shy and anxious. Earlier studies have linked long-term stress to poor memory, possibly because stress hormones can negatively affect the brain.
"In the past, studies have shown that chronic stress can affect parts of the brain, such as the hippocampus, possibly leading to dementia," said study author Hui-Xin Wang, Ph.D. "But our findings suggest that having a calm and outgoing personality in combination with a socially active lifestyle may decrease the risk of developing dementia even further." The findings appeared in Neurology, the medical journal of the American Academy of Neurology.
The study involved 506 seniors whose average age was 83. None had Alzheimer's when first examined.
The group filled out personality profiles to identify such traits as neuroticism, or the tendency to become easily distressed, and extraversion, or openness to interacting and chatting with others. Participants were also asked about how often they participated in hobbies and leisure-time activities, and how many friends they had.
After six years, 144 of the study participants had developed Alzheimer's or another form of dementia. Those who were socially active but who tended to remain calm and relaxed under pressure were 50 percent less likely to develop dementia than individuals who were isolated and easily stressed.
Protection against Alzheimer's was particularly strong among those who were socially outgoing and able to handle stress well. Extroverts who were calm and self-satisfied tended to have an optimistic outlook on life, the study found, and also had a 50 percent lower risk of developing Alzheimer's than outgoing people who were nervous and prone to worry.
The findings held, even after weighing other factors like years of schooling, depression or diabetes, or the presence of the APO-E4 gene, which predisposes to Alzheimer's onset.
"The good news is, lifestyle factors can be modified, as opposed to genetic factors, which cannot be controlled," Dr. Wang said. "But these are early results, so how exactly mental attitude influences risk for dementia is not clear."
Earlier studies have shown that people who remain active and socially engaged into old age have a lower Alzheimer's risk. Regular physical activity and keeping mentally alert through word games and other mental challenges can likewise help keep the mind sharp, research suggests.
Personality traits, too, have been linked to Alzheimer's risk. Researchers at Rush University in Chicago, for example, found that so-called conscientious people who are self-disciplined, goal oriented and "get the job done" may be less likely to develop the disease. [See the article, "Are You Conscientious? You May Be Less Likely to Get Alzheimer's"]
This study looked at both lifestyle and personality characteristics, providing further evidence that an outgoing, active social network and shaking off stress can be good for the mind, and the brain.
Source: H. -X. Wang, PhD, A. Karp, PhD, A. Herlitz, PhD, et al: "Personality and lifestyle in relation to dementia incidence." Neurology, Volume 72, January 20, 2009, pages 253-259.