The Name Of The Game: Leisure Activities In Early Adulthood Related To Lower Alzheimer's Risk Later In Life

The group's study – published in a recent issue of The Journal of Gerontology: Psychological Sciences – is the first to examine the relationship between leisure activities and the loss of mental function using data on twin pairs who differed in cognitive status.

"While we have not proved the adage 'use it or lose it,' it certainly makes sense that keeping an active mind contributes to positive aging," said lead author Michael Crowe, a doctoral student in psychology in USC's College of Letters, Arts & Sciences.

"It is very important to understand that what someone does early in life can affect how that person grows old," added co-author Margaret Gatz, a professor of psychology in the USC College.

Using records from the Swedish Twins Registry – a population-based set of data on twins living in Sweden – the team analyzed information on same-sex twins born between 1886 and 1925.

In the 1960s, the twins filled out questionnaires regarding their activities before age 40. They cited such interests as reading, social visits, theater and moviegoing, club participation, gardening and sports.

In the 1980s and 1990s, the subjects participated in clinical follow-ups, which included testing for dementia, which is classified as the loss of cognitive function due to changes in the brain caused by disease or trauma.

"The idea that mental activity is good for the brain is not unlike the idea of 'use it or lose it' when it comes to keeping the body fit," said co-author Ross Andel, a recent USC postdoctoral student who is now an assistant professor in the University of South Florida's gerontology department.

Analyzing 107 twin pairs where one twin was diagnosed with some type of cognitive impairment and the other was cognitively intact, the researchers – from USC, Sweden's University of Götenberg and Karolinska Institutet in Stockholm, Sweden – found that greater overall participation in leisure activities reduced the risk of developing dementia and Alzheimer's disease, even when education was taken into account.

Moreover, among female twins, the twin who participated frequently in "intellectual-cultural activities," such as getting together with friends or joining clubs, showed a reduced risk of Alzheimer's disease.

The team did not find significant differences when comparing data on the basis of gender. However, the data revealed that activity was relatively more protective for women than for men.

"It was surprising that intellectual and cultural activities were not equally protective for both sexes," Gatz said. "We speculate that men in this generation may have had more stimulating occupations than women did, so that difference in leisure activities assumed greater importance in women."

While more research is necessary to uncover which leisure and intellectual activities may preserve cognitive function and why, the team believes the difference made by greater overall activity is not explained by education or similarities within twin pairs, such as early-life environments or genetics.

"Our study would have been bolstered by greater detail regarding the twins' activities, but the fact that there was a 20-year or more time lag between activity data collection and dementia evaluation is an outstanding feature," Gatz said.

"We are now looking at larger samples, with greater detail focusing on leisure activities and levels of intellectual and social stimulation in the workplace," she added.

The study was funded by the National Institute on Aging, the Alzheimer's Association and the USC/UCLA Center on Biodemography and Population Health.