Life purpose, longevity, and Alzheimers disease.

From Hill and Turiano:

Having a purpose in life has been cited consistently as an indicator of healthy aging for several reasons, including its potential for reducing mortality risk. In the current study, we sought to extend previous findings by examining whether purpose in life promotes longevity across the adult years, using data from the longitudinal Midlife in the United States (MIDUS) sample. Proportional-hazards models demonstrated that purposeful individuals lived longer than their counterparts did during the 14 years after the baseline assessment, even when controlling for other markers of psychological and affective well-being. Moreover, these longevity benefits did not appear to be conditional on the participants’ age, how long they lived during the follow-up period, or whether they had retired from the workforce. In other words, having a purpose in life appears to widely buffer against mortality risk across the adult years.

(MIDUS refers to a longitudinal study of health and well-being that began in 1994–1995. 7,108 participants were recruited from a nationally representative, random-digit-dialing sample of noninstitutionalized adults between the ages of 20 and 75 (mean age = 46.92 years, SD = 12.94)).

An article by Span points to other studies following almost 1,000 people (age 80, on average) for up to seven years, finding that those with high purpose scores were 2.4 times more likely to remain free of Alzheimer’s than those with low scores and also less likely to develop mild cognitive impairment, often a precursor...In a subset of 246 people who died, autopsies found that many of the purposeful subjects also showed the distinctive markers of Alzheimer’s, suggesting that even for people developing the plaques and tangles in their brains, having purpose in life allows them to tolerate them and still maintain their cognition...Another study, of 1,238 people followed for up to five years (average age: 78)found that those with high purpose had roughly half the mortality rate of those with low purpose.