By Dr. Joey Ng

A large British study suggests that living with others, whether another person, or even a pet, may slow down the decline in cognitive skills that tends to come as people age.

Cognitive decline in older adults is a major public health issue, with almost 10% of U.S. adults ages 65 and older estimated to have dementia, and 32% estimated to have some degree of cognitive impairment. Previous research has shown that living alone and social isolation are associated with an increased risk of cognitive decline with age.

"Research indicates that having long-term, high-quality relationships, whether that’s with family, friends, or romantic relationships, is not only important for happiness, but for promoting good brain health and reducing the risk for dementia," said Dr. Leah Croll, assistant professor of neurology at the Lewis Katz School of Medicine at Temple University.

Pet ownership has been shown to reduce feelings of loneliness and isolation in those living alone, but up until now, no study had directly compared rates of cognitive decline between pet owners and non-pet owners.

The study found that pet ownership was associated with slower rates of decline in cognitive skills in older adults living alone, but not in those living with other people. There was no difference in rates of decline between pet owners living with others and pet owners living alone.

Croll commented on these findings, stating that pet ownership may potentially represent an "alternative option for people whose social circumstances don’t allow for them to have frequent interactions with other people."

The authors used data from 7,945 adults 50 years or older living in the U.K. They compared rates of decline in cognitive skills between pet owners and non-pet owners over a period of nine years.

Each year, the participants were asked to perform several tests: reciting 10 unrelated words immediately after they were given, and after a delay, and naming as many animals as they could in one minute. These tests were designed to measure verbal memory and verbal fluency, skills that are vital to performing daily tasks and remaining independent as one ages.

As the U.S. population ages and the number of single-person households increases, dementia and cognitive decline in older adults will likely become increasingly important public health issues.

This study suggests that even for those who can’t live with another person, a beloved pet may be protective against the effects that loneliness and social isolation have toward cognitive decline with age.

It should be noted that the study only tested two domains of cognition, and that further work needs to be done to provide a fuller picture of how to slow cognitive decline with age. From what research is available, Croll currently recommends that her patients "stay active, eat a heart-healthy diet like the Mediterranean diet, and keep in touch with their friends," in order to promote healthy aging and prevent cognitive decline.

Joey K. Ng, MD, is an emergency medicine resident at Wyckoff Heights Medical Center in Brooklyn, New York.