Owning a pet – especially a dog or cat – has been linked with slower rates of cognitive decline including verbal memory and fluency among older adults who live alone, while the same protective effect was not found in pet owners living with others.
Nearly 8,000 older people were studied by Chinese researchers who published their findings in JAMA Network Open: Neurology under the title “Pet Ownership, Living Alone, and Cognitive Decline Among Adults 50.” Dr. Ciyong Lu of Sun Yat-sen University in Guangzhou was the corresponding author of the research.
They used population data from June 2010 to July 2011 and from June 2018 to July 2019 that had been published in the English Longitudinal Study of Ageing in the UK.
Educational level, employment and social status were noted along with smoking and alcohol consumption, physical activity, self-rated general health, depressive symptoms, and the following self-reported conditions: diabetes, hypertension and cardiovascular disease. Some 56% of participants were women, and about a third of those studied had a dog or cat.
“Older adults living alone are at high risk for developing dementia, and living alone is a state that is not easily changed," they wrote. "As the population ages and life expectancy increases, a major public health issue is the deterioration of cognitive function in older adults.
"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," the study said.
"No effective therapy is currently available to successfully reverse cognitive decline or treat dementia. Thus, identifying high-risk populations and modifiable risk factors is crucial for formulating public health interventions and promoting healthy aging,” they wrote.
More adults are living alone than ever before
In 2021, the proportion of single-person households in the UK reached 29.4% and in the US 28.5%. A recent meta-analysis of 12 studies reported that older adults living alone are at high risk for developing dementia and that the population-attributable fraction for living alone is 8.9%. This figure will increase given that the proportion of older adults living alone is on the rise.
Compared with pet owners living with others, those living alone who didn’t have a pet had faster rates of decline in composite verbal cognition, than nonowners living with others or pet owners living alone.
The authors noted that further studies are needed to confirm whether the results were relevant in non-white and other populations. In addition, cognitive function includes multiple dimensions (such as episodic memory, executive function, attention, reasoning, processing speed and accuracy), but this study assessed only verbal memory and verbal fluency, which represent a single aspect each of episodic memory and executive function.