An Optimistic Outlook May Protect the Brain Against Dementia
核心洞察
A study of 9,071 cognitively healthy older adults found that those with the highest optimism scores were 15 percent less likely to develop dementia (搜索) over an average 14-year follow-up.
Researchers used the Revised Life Orientation Test to measure optimism and adjusted for education, depression, and other medical conditions, excluding early dementia (搜索) cases.
The authors suggest optimism may lower dementia (搜索) risk through reduced inflammation, stronger social networks, and healthier lifestyle choices.
Having an optimistic outlook on life may be good for the brain, according to a new report published in the Journal of the American Geriatrics Society. The study found that older adults who looked on the bright side of life were less likely to develop Alzheimer's disease (搜索) and other forms of dementia (搜索) as they aged.
Researchers analyzed data from 9,071 seniors who were part of the Health and Retirement Study, a long-running study of health and aging. The cohort included a diverse cross-section of cognitively healthy older Americans, all of whom had tests of memory and thinking skills at age 70 or older.
Measuring Optimism
Participants underwent psychological assessments to gauge their general levels of optimism using a scientifically validated survey called the Revised Life Orientation Test. They responded to a series of questions, including six related to optimism levels. Three questions gauged positive expectations for future outcomes, such as "In uncertain times, I usually expect the best," "I'm always optimistic about my future," and "Overall, I expect more good things to happen to me than bad." Three additional questions gauged negative expectations, including "If something can go wrong for me, it will," "I hardly ever expect things to go my way," and "I rarely count on good things happening to me." Participants responded on a five-point scale ranging from strongly disagree to strongly agree, and their scores were tallied to assess general optimism levels.
A 15 Percent Lower Dementia Risk
Researchers followed participants for an average of 14 years. During that time, 3,027 developed Alzheimer's disease (搜索) or other forms of dementia (搜索). The analysis revealed that men and women who exhibited the highest optimism scores were 15 percent less likely to develop dementia than their more pessimistic peers.
The researchers adjusted for factors that may have contributed to dementia (搜索) risk, including education levels and major medical conditions such as depression and other mental health disorders. They also excluded from the analysis anyone who developed dementia within two years of their cognitive test, since worry about memory loss and impending dementia may have affected their general optimism scores. Having an optimistic outlook appeared to be independently associated with a lower dementia risk.
How Optimism May Protect the Brain
The findings build on growing evidence linking optimism with a longer life and healthy aging in general, including improved brain health. A study from the prior year found that having a positive outlook on life in middle age was associated with higher scores on memory tests over the next 16 years.
The researchers note that several processes may help explain how optimism could influence dementia (搜索) risk. Earlier studies have shown that optimism may boost the immune system and lead to lower levels of inflammation in the brain. Increasingly, scientists believe that body-wide inflammation contributes to Alzheimer's disease (搜索). Being optimistic may also lead to stronger social networks, a well-recognized protector of brain health. It may also lead to healthier lifestyle choices, including increased physical activity and not smoking, which can lower Alzheimer's risk.
"Identifying optimism as a protective psychosocial factor highlights the potential value of optimism in supporting healthy aging," the authors concluded. They noted that while about 25 percent of optimism levels may be related to family genetics, numerous studies suggest that people can take steps to increase their positive outlook on life. Programs that utilize mindfulness meditation, keeping a gratitude journal, and limiting exposure to negative news and people with negative outlooks have been shown to boost optimism levels. Psychological counseling that helps reframe negative thoughts can also help.
"There are interventions that successfully shift individuals' views and beliefs about the future, a shift that could potentially improve an individual's quality of life, long-term health, and possibly the risk of dementia (搜索), as suggested by our study," the researchers note. "Randomized trials designed to increase optimism among older adults may also be informative and further inform whether optimism learned or increased later in life also contributes to maintaining healthy cognitive function."
The study was authored by Sade Stenlund, Hayami K. Koga, Peter James, and colleagues, and reviewed by Eric Schmidt, Ph.D., of the Fisher Center for Alzheimer's Research Foundation at The Rockefeller University.