Leisure Activity and Dementia Risk: When Does It Matter?

Participating in leisure activities such as reading or going to the movies at age 56 was not linked to less dementia risk 18 years later, the longitudinal Whitehall II study showed.

But higher participation at age 66 was tied to a lower likelihood of dementia over 8.3 years, suggesting leisure activity declines during the preclinical stage of dementia, reported Andrew Sommerlad PhD, of University College London, and colleagues, in Neurology.

For each standard deviation higher on total leisure activity, dementia risk was 18% lower (HR 0.82, 95% CI 0.69-0.98) when the mean follow-up was 8.3 years, 12% lower (HR 0.88, 95% CI 0.76-1.03) at 13 years of follow-up, and 8% lower (HR 0.92, 96% CI 0.79-1.06) at 18 years.

The finding doesn’t question the importance of keeping active, “but it does suggest that simply increasing leisure activity may not be a strategy for preventing dementia,” Sommerlad said in a statement.

“More research is needed to confirm these results, but we know that early changes in the brain can start decades before any symptoms emerge,” he added. “It’s plausible that people may slow down their activity level up to 10 years before dementia is actually diagnosed, due to subtle changes and symptoms that are not yet recognized.”

While the outcomes may appear to contradict earlier research suggesting leisure activity may protect against dementia, most of those studies had shorter follow-up periods, Sommerlad and colleagues noted.

“Leisure activity is linked to reduced risk of cognitive decline, mild cognitive impairment, and dementia, but these associations are often based on activity occurring less than a decade before dementia is diagnosed,” noted Victor Henderson, MD, of Stanford University in Palo Alto, and Merrill Elias, PhD, MPH, of the University of Maine in Orono, in an accompanying editorial.

One interpretation is that leisure activity may help stave off dementia symptoms even when subclinical neuropathology is present, perhaps by enhancing cognitive reserve, they said. “A second possibility is that early neural dysfunction in pathways that underlie motivation and goal-directed behavior makes it more difficult to initiate and sustain leisure activity,” they added.

The analysis looked at 8,280 participants of the Whitehall II prospective cohort study in Britain; 69% were male, 91% were white, and mean age at the start of follow-up was about 56.

At three points — 1997-1999, 2002-2004, and 2007-2009 — researchers assessed how frequently participants engaged in 13 types of leisure activities in the past year. Leisure activities ranged from reading, music, and taking classes to cultural, religious, and social events. Dementia diagnoses were derived from three linked electronic health records (EHR).

Overall, 360 incident dementia cases were recorded over the follow-up period (incidence 2.4 per 10,000 person-years). Mean age at diagnosis was about 76. No specific activities were consistently associated with dementia risk.

Participants whose activity level dropped over the course of the study were more likely to develop dementia than those whose activity, even if low, stayed the same. A total of 5% of 1,159 people whose activity decreased developed dementia, compared with 2% of 820 people whose activity level stayed low over the years.

“Large, long duration, randomized controlled trials could provide even stronger evidence of any causal relationship” between leisure activity and dementia, Henderson and Elias wrote. Studies that focus on lifestyle interventions, like the POINTER study in the U.S., may shed better light.

“Midlife and late-life leisure activity certainly does no harm, but its role in dementia prevention is not yet clear,” they observed. “There is more work to be done.”

One limitation of the study was that dementia diagnoses were gathered from EHR and some cases may not have been diagnosed, the researchers noted. The study also did not consider dementia subtypes or intensity of leisure activity.