Owning a pet may slow rate of cognitive decline, study suggests

NEW YORK, Dec. 26 (UPI) -- Owning a pet may slow the rate of cognitive decline among older adults living alone, new research suggests.

The study from China was published Tuesday in JAMA Network Open.

Pet ownership was associated with more gradual rates of decline in verbal memory, verbal fluency and composite verbal cognition among the older adults studied, but not among those living with others.

The investigators from the School of Public Health at Sun Yat-sen University in Guangzhou, used data from the English Longitudinal Study of Aging, an ongoing nationally representative sample of community-dwelling adults 50 years old and older in the United Kingdom.

They noted that Identifying high-risk populations and modifiable risk factors is essential for establishing public health interventions and promoting healthy aging. Yet, as the authors pointed out, no effective therapy exists to successfully reverse cognitive decline or treat dementia.

"As the population ages and life expectancy increases, a major public health issue is the deterioration of cognitive function in older adults," they wrote. "It is estimated that the number of people with dementia worldwide will increase from 57 million in 2019 to 153 million in 2050.

"The deterioration of cognitive function not only seriously impairs individuals' well-being, but also brings a huge burden to their caregivers, as well as the financial and health systems of society."

Meanwhile, the proportion of older adults living alone is trending upward.

"Contrary to living alone," the authors wrote, "pet ownership (for example, raising dogs and cats) is related to reduced loneliness, an important risk factor for dementia and cognitive decline."

The authors noted that their "findings provide innovative insights for developing public health policies to slow cognitive decline in older adults living alone."

They noted that randomized clinical trials are still needed to evaluate whether pet ownership slows the rate of cognitive decline in older adults living alone.

Their analysis represents one of the largest studies to date examining the association between pet ownership, loneliness and cognitive decline, said Dr. Peter Rabinowitz, a professor in the School of Medicine and the School of Public Health at the University of Washington in Seattle.

"The study provides further evidence for a beneficial impact of pet ownership on mental health," said Rabinowitz, who also directs the Center for One Health Research, which explores the connections between the health of people, animals and environment.

"Most of the previous studies have been smaller and cross-sectional -- at a single point in time," he said. "This study followed participants for longer than most other studies."

The authors also "controlled for other factors such as age and physical health, providing some reassurance that the results showing a benefit of pet ownership were not due to some other difference between people who own pets and those who don't," Rabinowitz said.

However, he added that the authors did not differentiate between the ownership of a dog, cat or other animal. And they did not confirm that pets were continuously owned during the follow-up period.

Also, Rabinowitz said, they assessed only some aspects of cognitive function, so the same benefit may not extend to other types of cognition. And the population they studied was overwhelmingly white, limiting generalizability to other ethnic groups.

Dr. Steven Wengel, a professor and geriatric psychiatry division director at the University of Nebraska Medical Center in Omaha, said that "If these findings are replicated in other studies, it could lead to recommending getting a pet for older adults who live alone as one strategy for improving their overall health and, in particular, to possibly reduce the risk of cognitive issues, including dementia."

Wengel added that "it's too soon to make that leap, but the data from this study looks promising. It would be important to look at other cognitive measures and the impact of pet ownership on those measures over time."

He also noted that "as our surgeon general, Dr. Vivek Murthy, says, an epidemic of loneliness and isolation is occurring. I am glad to see research being conducted on a potential way to reduce loneliness in older adults living alone and which may promote better brain health, too."

Dr. Thomas Wisniewski, a neurologist and director of the Pearl I. Barlow Center for Memory Evaluation and Treatment at NYU Langone Health in New York City, told UPI in a telephone interview that walking a dog regularly benefits brain health.

"Being physically active is protective against dementia and also can help slow down disease progression," Wisniewski said. "It's a nice study, and it fits in well with the existing literature."

Pet ownership also encourages socialization, said Dr. Cari Levy, a geriatrician and professor of medicine at the University of Colorado School of Medicine in Aurora, Colo.

"People come up and say 'Hi'," when they see someone walking a dog. "This [study] makes a lot of sense intuitively," Levy said, adding that "there are certainly very few risks associated with [pet ownership] as long as the person is able to care for the animal."

Taking care of a pet can instill a sense of purpose, while also improving mood disorders, which have been linked to cognitive decline, said Dr. Parul Mani Goyal, a geriatrician and associate professor of medicine at Vanderbilt University School of Medicine in Nashville.

"All of this can help with patients' overall health when they are alone -- and might help with their memory," Goyal said.