- In older adults, higher optimism was associated with a 15% lower risk of developing dementia.
- Associations were similar in both white and black participants across several health adjustments.
- The findings are consistent with other research that suggests optimism is linked to healthy aging.
A study of nearly 9,100 people showed that people exposed to sunlight had a lower risk of dementia.
Sade Stenlund, MD, PhD, of the Harvard TH Chan School of Public Health in Boston, and colleagues reported that over 14 years, after adjusting for age, gender, race and ethnicity, education, depression, and major health conditions, each standard deviation increase in optimism was associated with a 15% lower risk of developing dementia (HR 0.85, 95% CI 0.82-0.88).
The associations were similar in both white and black subgroups, Stenlund and colleagues wrote. Journal of the American Geriatrics Society. When researchers adjusted for health behaviors, removed the first 2 years of follow-up to reduce the risk of reverse causation, or excluded people with the worst mental health, the relationships did not change significantly.
“The findings highlight how our personal emotional and social resources – such as how hopeful and positive we feel about the future – may be related to keeping our brains healthy as we age,” Stenlund said.
“Our study offers promising new directions for preventing dementia. It suggests that psychological factors such as optimism may eventually be part of strategies to reduce dementia risk,” he said. Medpage Today.
“Since optimism can be increased through relatively simple, low-intensity programs, it is useful to understand how it relates to health in aging,” Stenlund added. “We don’t yet know whether boosting optimism in this way is actually strong enough to change a person’s long-term dementia risk. Future research, such as randomized trials, needs to test this directly, but our work is important in terms of building the evidence base for these studies.”
Prior research supports the idea that optimism is linked to healthy aging. For example, in a meta-analysis of 15 studies and 230,000 people, optimism was linked to a lower risk of cardiovascular events, while pessimism was linked to a greater risk of cardiovascular events. The pooled association was similar to other well-established cardiovascular risk factors.
In 2022, a study of 159,000 participants of the Women’s Health Initiative showed that higher optimism correlated with longer life span And are more likely to live to age 90 or older. That same year, data from 7,200 postmenopausal women revealed that less pessimism — but not greater optimism — was associated with a lower risk of mild cognitive impairment and dementia.
Stenlund and colleagues evaluated data from 9,071 cognitively healthy individuals Health and Retirement Study (HRS) to assess whether optimism was associated with a reduced risk of developing dementia and whether the relationship persisted after accounting for initial health status and other potential confounders.
Within 2 years of obtaining each individual’s first measurement of cognitive function, optimism was measured using the Life Orientation Test-Revised, a six-item scale measuring dispositional optimism. Cognitive assessments were conducted at each of eight waves of data collection from 2006 to 2020. Dementia status was obtained using an algorithm specifically developed at HRS to take into account racial and ethnic differences more accurately than other algorithms.
The average age of participants at baseline was 74 years. The follow-up period ranged from 2 to 14 years, with a mean of 6.7 years. During this period, 3,027 individuals developed dementia.
Stenlund and colleagues observed that the association between high optimism and reduced dementia risk in this analysis is consistent with previous HRS studies with shorter follow-up times.
“Our study is the first to directly address concerns about reverse causation, which is an important issue because psychological symptoms, such as low mood, represent early symptoms of dementia,” they wrote.
However, the opposite cause was still a possibility, the researchers acknowledged. “As with any observational study, the possibility of residual or unmeasured confounding remains,” he said.
