Risk of leisure activities and dementia: when does it matter?

Participation in recreational activities such as reading or going to the movies at age 56 was not linked to a lower risk of dementia 18 years later, the Whitehall II longitudinal study showed.

But higher participation at age 66 was linked to a lower probability of dementia over 8.3 years, suggesting a decline in leisure activity during the preclinical stage of dementia, said Andrew Sommerlad PhD, of ‘University College London, and colleagues, in Neurology.

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

The finding does not question the importance of staying active, “but it suggests that simply increasing recreational activities may not be a strategy to prevent dementia,” Sommerlad said in a statement.

“More research is needed to confirm these findings, but we know that the first changes in the brain can begin decades before symptoms emerge,” he added. “It is plausible that people can slow their activity level for up to 10 years before dementia is actually diagnosed, due to subtle changes and symptoms that have not yet been recognized.”

While the findings may appear to contradict previous research suggesting that recreational activity may protect against dementia, most of these studies had shorter follow-up periods, Sommerlad and colleagues noted.

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

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

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

At three points – 1997-1999, 2002-2004, and 2007-2009 – the researchers assessed how often participants engaged in 13 types of leisure activities in the past year. Recreational activities ranged from reading, music and lectures to cultural, religious and social events. The dementia diagnoses were derived from three linked electronic health records (EHRs).

Overall, 360 cases of incident dementia were recorded in the follow-up period (incidence 2.4 per 10,000 person-years). The mean age at diagnosis was approximately 76 years. No specific activity was consistently associated with the risk of dementia.

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

“Long-term and large randomized controlled trials could provide even stronger evidence of any causal relationship” between recreational activity and dementia, Henderson and Elias wrote. Studies focusing on lifestyle interventions, such as the POINTER study in the United States, may shed a better light.

“Midlife and late life recreational activities certainly don’t hurt, but its role in preventing dementia is still unclear,” they noted. “There is still a lot of work to do”.

A limitation of the study was that dementia diagnoses were gleaned from EHR and some cases may not have been diagnosed, the researchers noted. The study also did not take into account the subtypes of dementia or the intensity of leisure activity.