Owning a pet, especially for five years or longer, may be linked to slower cognitive decline in older adults, according to a preliminary study from the University of Michigan Medical Centre, while a second one, undertaken in Japan, shows that senior dog-owners are half as likely as non dog-owners to have a disability although interestingly, owning a cat made no difference.
Previous studies have long suggested that the human-animal bond may have health benefits, like decreasing blood pressure and stress. Now, said author Dr Tiffany Braley, of the University of Michigan Medical Center in Ann Arbor and a member of the American Academy of Neurology, “our results suggest pet ownership may also protect against cognitive decline.”
The research looked at cognitive data from 1,369 older adults with an average age of 65 who had normal cognitive skills at the start of the study: 53% owned pets, and 32% were long-term pet owners, defined as those who owned pets for five years or more. Of study participants, 88% were white, 7% were black, 2% were Hispanic and 3% were of another ethnicity or race.
Researchers used data from the Health and Retirement Study, a large study of Medicare beneficiaries. In that study, people were given multiple cognitive tests. Researchers used those cognitive tests to develop a composite cognitive score for each person, ranging from zero to 27. The composite score included common tests of subtraction, numeric counting and word recall. Researchers then used participants’ composite cognitive scores and estimated the associations between years of pet ownership and cognitive function.
Over six years, cognitive scores decreased at a slower rate in pet owners. This difference was strongest among long-term pet owners. Taking into account other factors known to affect cognitive function, the study showed that long-term pet owners, on average, had a cognitive composite score that was 1,2 points higher at six years compared with non-pet owners. The researchers also found that the cognitive benefits associated with longer pet ownership were stronger for black adults, college-educated adults and men. Braley says more research is needed to further explore the possible reasons for these associations.
“As stress can negatively affect cognitive function, the potential stress-buffering effects of pet ownership could provide a plausible reason for our findings,” she said. “A companion animal can also increase physical activity, which could benefit cognitive health. That said, more research is needed to confirm our results and identify underlying mechanisms for this association.”
A limitation of the study was that length of pet ownership was assessed only at one time point, so information regarding ongoing pet ownership was unavailable.
The study will be presented at the American Academy of Neurology’s 74th Annual Meeting being held in person in Seattle from 2-7 April 2022 and virtually from 24-26 April 2022.
In the Japanese study, carried out by Yu Taniguchi of the National Institute for Environmental Studies in Tsukuba, and colleagues, it was found that while dog owners were approximately half as likely to have a disability, there was no difference in risk for cat owners
The findings of their analysis of data from more than 11,000 older Japanese adults, suggesting dog-owning seniors may be at lower risk of disability than those who have never been dog owners, were published in the journal PLOS ONE.
Earlier studies by these researchers have linked dog ownership among Japanese seniors with a lower risk of frailty, a relationship that appears to be partially explained by higher levels of physical activity and social functioning among dog owners. Other research also suggests that physical frailty significantly boosts risk of future disability.
To better understand the relationship between dog ownership and risk of disability, Taniguchi and colleagues used questionnaires to collect data on dog and cat ownership from 11,233 Japanese adults aged 65 to 84. They also collected demographic, disability, and other health data for the participants, spanning the period of June 2016 to January 2020. Statistical analysis of the combined datasets enabled them to examine potential links between dog ownership and disability risk.
They found that during the study period, older adults who were current dog owners were approximately half as likely to have a disability than those who had never been dog owners. This relationship held true even after accounting for other sociodemographic and health factors that could influence disability risk, such as marital status, history of chronic diseases, time spent outdoors, and more. In addition, dog owners who exercised regularly had an even lower risk of disability.
Meanwhile, the researchers found, cat ownership was not associated with any difference in disability risk, and neither dog nor cat ownership was associated with reduced risk of death from any cause.
This study suggests that dog ownership, especially combined with regular exercise, might protect against disability for older Japanese adults. These findings could help inform efforts to promote successful ageing. Meanwhile, future research could investigate physical or psychological mechanisms by which dog ownership might provide benefits, or examine relationships between dog ownership and disability risk in other countries.
Study details
Evidence that dog ownership protects against the onset of disability in an older community-dwelling Japanese population.
Yu Taniguchi, Satoshi Seino, Bruce Headey, Toshiki Hata, Tomoko Ikeuchi, Takumi Abe, Shoji Shinkai, Akihiko Kitamura.
Published in PLOS ONE on 23 February 2022.
Abstract
Objectives
This study examined the association between dog and cat ownership, the onset of disability and all-cause mortality in an older population. Dog and cat owners take more regular exercise and have closer social relationships than non-owners. We further assess the beneficial effects of these moderating variables on the onset of disability and mortality.
Methods
Dog and cat ownership data were collected from 11,233 community-dwelling adults age 65 years and older. These data were matched with data about the onset of disability held by the Japanese long-term care insurance system. Local registry data were used to ascertain all-cause mortality.
Results
During the approximately 3,5 year follow-up period, 17,1% of the sample suffered onset of disability, and 5,2% died. Logistic regression analysis indicated that, compared with a reference group of those who had never owned a dog (odds ratio fixed at 1,0), older adults who were currently dog owners had a significantly lower odds ratio of onset of disability (OR = 0,54 95% CI: 0,37–0,79). Our results further show that regular exercise interacts with dog ownership to reduce the risk of disability. The association of dog and/or cat ownership with all-cause mortality was not statistically significant.
Conclusions
Dog ownership appears to protect against incident disability among older Japanese adults. Additional benefits are gained from ownership combined with regular exercise. Daily dog care may have an important role to play in health promotion and successful ageing.
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If you want a heart, get a dog
Influence of pets on childhood development