Owning a pet could protect against the mental decline that can foreshadow dementia in older folks living alone, a study of nearly 8,000 people has found.

The findings of the sizeable UK study add to existing evidence from the US that having a pet can help buffer against the effects of brain aging in adults aged over 65 years old and living alone.

Loneliness and dementia are two growing global problems. It's estimated that the number of people with dementia worldwide will increase from 57 million in 2019, to somewhere between 130 and 175 million in 2050.

Loneliness is also on the rise globally, and linked to a greater risk of developing dementia in older age.

However, people can be socially isolated without feeling lonely, and even a lack of social interaction is known to change the structure of the brain whilst impacting health and well-being in other ways.

For older folks who might not be able to venture outside their home, owning a pet can give them structure to their days and companionship, which may keep them more physically active, talkative, or connected to their neighbors than people living alone without any pets.

It's an uplift many of us may have felt during the pandemic, thanks to our beloved pets. And there's plenty of research showing how pets of any kind can make us feel more connected.

But the extent to which pet ownership might counterbalance the downward slide in mental capacity associated with older adults living on their own hasn't been studied as much.

To investigate, Yanzhi Li, a public health researcher at Sun Yat-sen University in China, and colleagues analyzed data on 7,945 people from the English Longitudinal Study of Aging (ELSA), an ongoing study of UK residents over 50 years old.

Information on pet ownership was first collected in the fifth wave of the study, between June 2010 and July 2011, and the researchers tracked people's cognitive function scores through to July 2019, the ninth and most recently completed phase of the study.

Compared to those living entirely on their own, people living with no one but their pets had slower rates of cognitive decline in three key areas: verbal cognition, verbal memory, and verbal fluency.

Pets didn't make a difference for older individuals living with other people. Among solo-dwelling pet owners, however, pet ownership "completely offset" the known effects of living alone on verbal memory and fluency, Li and colleagues found.

"Our results provide stronger evidence and more nuanced insights into the benefits of pet ownership on verbal memory and verbal fluency among older adults living alone," the researchers write in their paper.

However, they also acknowledge that there's more to cognition than processing, understanding and remembering words, and speaking fluently.

Attention, reasoning, processing speed, episodic memory, and accuracy are just some other aspects of cognitive function that could be assessed in future studies with older adults, including pet owners and those without.

The study participants were mostly White as well, so more research involving people of other ethnicities is needed to see if those groups get the same benefit from owning a pet.

The ELSA study also didn't record how long people had been pet owners, so it's hard to know whether introducing a new furry friend, feathered, or perhaps scaly friend could possibly slow mental decline the same way a years-long pet companion might.

Of course, as with any observational study, the findings of this research only suggest an association between pet ownership and brain function, and don't provide the kind of direct evidence that clinical trials would.

"If randomized clinical trials confirm our findings, pet ownership may help in slowing cognitive decline and preventing dementia," the team concludes.

The study has been published in JAMA Network Open.