Study Authors: Andrew Sommerlad, Séverine Sabia, et al.; Victor W. Henderson, Merrill F. Elias
Target Audience and Goal Statement: Geriatricians, neurologists, primary care physicians, psychiatrists
The goal of this study was to examine the association between participation in leisure activities and incident dementia.
Questions Addressed:
- Was leisure activity
participation associated with lower risk of incident dementia in a
large longitudinal study with an average 18-year follow-up?
- How
does length of follow-up affect the associations between activity
participation and dementia; specific activities and dementia; and
leisure activity change over 10 years and subsequent incident dementia?
Study Synopsis and Perspective:
The aging population and the lack of any disease-modifying treatments
for dementia have increased interest in modifiable lifestyle factors
that might help prevent or delay cognitive decline and onset of
dementia, and maintain quality of life in old age.
- There
was no evidence of a protective association between leisure activity
participation and dementia, and no specific type of leisure activity was
consistently associated with dementia risk, according to a large
longitudinal study of London-based civil servants.
- The findings
suggest that decreases in leisure activity participation may be a
prodromal feature of dementia, and simply increasing activities may not
be a strategy for preventing dementia.
Leisure
activities, i.e., pursuits engaged in for relaxation or pleasure
outside of work and household responsibilities, have been studied
extensively in this regard, since such activity involves three key
aspects of cognitive reserve: mental activity, physical activity, and
social engagement.
According to recent results from the longitudinal Whitehall II study,
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.
However, 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, 95% CI 0.79-1.06) at 18
years.
While the outcomes may appear to contradict earlier research suggesting that leisure activity may protect against dementia,
most of those studies had shorter follow-up periods, assessing the
effects of leisure activity that occurred less than a decade before
diagnosis of dementia, the researchers noted.
Sommerlad and team evaluated the activities of 8,280 London-based civil servants in the Whitehall II prospective cohort study; 69% were men, 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 --
Sommerlad and team 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.
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. Five percent of 1,159 people whose
activity decreased developed dementia compared with 2% of 820 people
whose activity level stayed low over the 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."
One limitation of the study was that dementia diagnoses were gathered
from electronic health records and some cases may not have been
diagnosed, the researchers noted. The study also did not consider
dementia subtypes or physical intensity of leisure activity.
Source References: Neurology 2020; DOI: 10.1212/WNL.0000000000010966
Editorial: Neurology 2020; DOI: 10.1212/WNL.0000000000010962
Study Highlights and Explanation of Findings:
In contrast to previous, mostly shorter-term,
studies (lasting less than 10 years), this longitudinal study found no
robust evidence for a protective association between leisure activity
participation and dementia, and no specific type of leisure activity was
consistently associated with dementia risk.
"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, California, and Merrill Elias, PhD, MPH, of the University of
Maine in Orono, in an accompanying editorial.
Among previous studies of specific activities, a large Australian assessment of computer use
among 5,506 community-dwelling men ages 69 to 87 followed for up to 8.5
years found that, compared with no computer use, the adjusted risk for
dementia appeared to decrease with increasing frequency of computer use,
by almost 40% with at least weekly or daily use.
One recent study
of people in England age 50 or older participating in cognitively
stimulating activities over an 8-year follow-up found that volunteering
and internet use were associated with reduced risk of cognitive
impairment.
One interpretation proposed by Henderson and Elias is that leisure
activity may help stave off dementia symptoms even when subclinical
neuropathology is present, perhaps by enhancing cognitive reserve. "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.
Indeed, apathy may be significant:
in cognitively normal older people, a recent prospective study showed
that those with severe apathy were nearly twice as likely to develop
probable dementia compared with those who had low levels of apathy (HR
1.9, 95% CI 1.5-2.5, P<0.001) over 9 years of follow-up,
providing novel evidence for apathy as a prodrome of dementia. While it
is often concurrent with depression, apathy is neuroanatomically
distinct in being correlated to the dorsolateral prefrontal cortex and
associated sub-regions in the basal ganglia.
Apathy was also associated with an approximately two-fold increased risk of dementia in a meta-analysis
involving over 7,000 memory clinic patients. Adjustment for apathy
definition and duration of follow-up explained 95% of heterogeneity in
patients with mild cognitive impairment; these results seem
generalizable to memory clinic populations, suggesting that apathy
deserves more attention as a relevant, cheap, noninvasive, and easily
measureable marker of increased risk for incident dementia, particularly
because these vulnerable patients may forgo healthcare.
Thus, clinicians should be alert for signs of apathy
-- marked by decreases in motivation and initiative, energy and
enthusiasm, and gradual social withdrawal, which generally occur about 1
to 2 years before other symptoms of dementia. One expert geriatrician
characterized apathy as a spectrum that follows that of dementia, and
links worsening apathy with cognitive decline -- a process that can be
slowed if apathy is assessed using a validated scale, such as the Apathy Evaluation Scale, and if diagnosed, treated.
"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 POINTER 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."
Sommerlad and colleagues suggested that future research should
investigate the socio-behavioral, cognitive, and neurobiological drivers
of decline in leisure activity participation to determine potential
approaches to improving social participation in those developing
dementia.
"Our novel finding of association of dementia with activity decline
and the timing of this decline suggests that changes in leisure activity
participation may be a prodromal feature of dementia, which is
consistent with retrospective accounts of decline in participation in
activities preceding dementia onset. There should therefore be awareness
among clinicians that those who decrease leisure activities in the
absence of other causes might be developing dementia," the group
concluded.
