Research into Blue Zones -- regions of the world where people tend to live longer -- shows that having a sense of purpose in life may help people live longer.
Now, new research from UC Davis shows that having a sense of purpose in life may have another benefit as people age: reducing the risk of dementia.
The new study, published in The American Journal of Geriatric Psychiatry, followed over 13,000 adults aged 45 and older for up to 15 years.
Researchers found that people who reported a higher sense of purpose in life were about 28% less likely to develop cognitive impairment -- including mild cognitive impairment and dementia.
The protective effect of having a purpose was seen across racial and ethnic groups. It also remained significant even after accounting for education, depression and the APOE4 gene, which is a known risk factor for Alzheimer's disease.
Purpose in life helps the brain stay resilient
"Our findings show that having a sense of purpose helps the brain stay resilient with age," said Aliza Wingo, senior author and professor in the UC Davis Department of Psychiatry and Behavioral Sciences. "Even for people with a genetic risk for Alzheimer's disease, sense of purpose was linked to a later onset and lower likelihood of developing dementia."
Participants were not specifically asked about the activities that gave their life purpose. Previous studies on aging, though, have found a wide rang of activities give older adults a sense of life purpose, sometimes referred to as "ikigai." These include:
- Relationships: Caring for family, spending time with grandchildren or supporting a spouse or friend.
- Work or volunteering: Continuing professional work, mentoring or contributing to community causes.
- Spirituality or faith: Religious beliefs, spiritual practices or involvement in faith-based communities.
- Personal goals: Pursuing hobbies, learning new skills or setting and achieving personal milestones.
- Helping others: Acts of kindness, philanthropy, caregiving or advocacy work.
Purpose delays onset of cognitive decline
Researchers also found that people with higher purpose tended to experience cognitive decline later than those with lower purpose. On average, the delay in onset was very modest -- about 1.4 months over an eight-year period, after considering the effects of age, education, depressive symptoms, and genetic risk. However, it is meaningful when compared to current treatments.
"While medications like lecanemab and donanemab can modestly delay symptoms of cognitive impairment in Alzheimer's disease, they come with risks and costs," said Nicholas C. Howard, first author and public health researcher at UC Davis. "Purpose in life is free, safe and accessible. It's something people can build through relationships, goals and meaningful activities."
Methods and limitations of study
Participants in the study were part of the Health and Retirement Study, a nationally representative survey funded by the National Institute on Aging. All had normal cognitive health at the beginning of the study.
Researchers used a seven-item survey from the Ryff Measures of Psychological Well-being.Participants had six possible responses (from "strongly agree" to "strongly disagree") for statements such as: "I am an active person in carrying out the plans I set for myself" and "I have a sense of direction and purpose in my life." Their answers were scored and averaged to obtain a well-being number between 1 and 6, with higher values indicating a strong sense of purpose in life.
Their cognitive health was tracked using a telephone-based test every two years.
The researchers noted the study has many strengths, including the size of the population studied. However, a key limitation is that although there was an association, the study did not prove higher levels of purpose caused the lowered rates of dementia.
Findings support role of psychological well-being
Still, the findings support the idea that psychological well-being plays a key role in healthy aging, said Thomas Wingo, a co-author of the study and a professor and neurologist at UC Davis Health. Wingo hopes future studies will explore whether purpose-building interventions can help prevent dementia.
"What's exciting about this study is that people may be able to 'think' themselves into better health. Purpose in life is something we can nurture," he said. "It's never too early -- or too late -- to start thinking about what gives your life meaning."