A Purposeful Life can Protect the Brain from Dementia

Research on so-called Blue Zones—regions of the world where people tend to live longer—shows that having a sense of purpose in life can contribute to longevity. A new study from UC Davis suggests that having a sense of purpose in life may have another benefit as we age: reducing the risk of developing dementia.

How Meaning in Life and Dementia Risk are Related

The new study, published in the American Journal of Geriatric Psychiatry, followed more than 13,000 adults aged 45 and older for up to 15 years. The researchers found that people who reported having a higher life purpose were about 28% less likely to develop cognitive impairment—including mild cognitive impairment and dementia. The protective effect of a life purpose was seen across all ethnic groups. It remained significant even after taking into account education, depression, and the APOE4 gene, a known risk factor for Alzheimer’s disease.

“Our findings show that a sense of purpose in life helps the brain remain resilient as we age,” said Aliza Wingo, senior author and professor at the UC Davis Department of Psychiatry and Behavioral Sciences. “Even in people with a genetic risk for Alzheimer’s disease, a sense of purpose in life was associated with a later onset and a lower likelihood of developing dementia.”

Participants were not specifically asked about the activities that gave their lives meaning. However, previous studies on aging have found that a variety of activities give older adults a sense of purpose in life, sometimes referred to as “ikigai.” These include:

• Relationships: Caring for family, spending time with grandchildren, or supporting a spouse or friends.
• Work or volunteerism: Continuing to work, mentoring, or volunteering for charitable causes.
• Spirituality or faith: Religious beliefs, spiritual practices, or involvement in faith communities.
• Personal goals: Pursuing hobbies, learning new skills, or setting and achieving personal milestones.
• Helping others: Friendly acts, philanthropy, caregiving, or advocacy.

A Purpose in Life Delays the Onset of Cognitive Decline

The researchers also found that people with a higher purpose in life tended to experience cognitive decline later than people with a lower purpose in life. On average, the delay in onset was very small—about 1.4 months over an eight-year period, taking into account the effects of age, education, depressive symptoms, and genetic risk. However, compared to current treatment methods, this is significant.

According to Nicholas C. Howard, first author and public health researcher at UC Davis, certain medications can slightly delay the symptoms of cognitive impairment in Alzheimer’s disease, but they come with risks and costs. A sense of purpose in life, on the other hand, is free, safe, and easy to achieve. It can be built through relationships, goals, and meaningful activities.

Methods and Limitations of the Study

The study participants 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 start of the study. The researchers used a seven-point questionnaire from the Ryff Measures of Psychological Well-being. Participants had six possible responses (from “strongly agree” to “strongly disagree”) to statements such as: “I am an active person when it comes to implementing the plans I have set for myself” and “I have a sense of direction and meaning in my life.” Their responses were scored and averaged to produce a well-being score between 1 and 6, with higher scores indicating a strong sense of meaning in life.

Their cognitive health was assessed every two years using a telephone test. The researchers noted that the study has many strengths, including the size of the population studied. However, a significant limitation is that while a correlation was found, the study could not prove that higher levels of meaning led to lower rates of dementia.

Nevertheless, the findings support the assumption that mental well-being plays an important role in healthy aging, according to Thomas Wingo, co-author of the study and professor and neurologist at UC Davis Health. Wingo hopes that future studies will investigate whether measures to strengthen the meaning of life can contribute to the prevention of dementia.