In a comprehensive study led by the Tokyo Metropolitan Institute for Geriatrics and Gerontology published in the National Library of Medicine in Dec 2023, researchers have uncovered a noteworthy link between pet ownership and dementia risk among older adults.
The study involved over 11,000 individuals aged between 65 and 84 comprising approximately 10% of the older population of Ota City, Tokyo Japan, and explored the connection between having pets, specifically cats and dogs, and their weekly exercise habits, including activities like walking, running, yoga, swimming, and cycling. The study took place over a 4-year period with the scientists checking for incident disabling dementia using data from the long-term care insurance system (LTCI) among participants.
The study found that owning a dog played a role in reducing the occurrence of severe dementia over a follow-up period of about four years, taking into account various background factors. Notably, dog owners who regularly exercised and were not socially isolated experienced a considerably reduced risk of severe dementia. The act of caring for a dog may help in preserving physical activity, including routine exercise, and facilitate social engagement, even under restrictive conditions like those imposed during the COVID-19 pandemic.
What did the study find?
To summarize, the study found that:
- Having a dog reduces the likelihood of developing severe disabling dementia.
- Regular exercise and social connectivity among dog owners lead to a markedly decreased risk of dementia.
- On the other hand, owning a cat does not show a significant impact in warding off dementia compared to dogs (Dog owners had a calculated odds-ratio risk of 0.6, while cat owners stood at 0.98 risk, the study found)
The findings, particularly intriguing in the realm of dementia research, indicate that dog owners have a lower risk of developing dementia compared to cat owners or those without pets. The research employed an “odds ratio” method for analysis, revealing that dog owners had a risk factor of 0.6, while cat owners had a slightly higher risk at 0.98. Notably, individuals without any pets were at a baseline risk of 1.0, suggesting that cat ownership had very minimal or no difference in reducing dementia risk.
One of the key insights from this study is the significant impact of pet dogs on the owners’ lifestyles. Dog owners generally ventured outside more often, leading to increased social interactions. This heightened social engagement is considered to have a “suppressive effect” on the development of dementia. Additionally, the physical activity associated with dog ownership, such as regular walks, is believed to reduce the build-up of brain proteins linked to dementia. Regular exercise also promotes better cerebral blood flow, cell growth, and survival, all contributing factors to a reduced risk of cognitive decline.
Dr Yu Taniguchi, the lead author of the study, noted the beneficial effects of dog ownership in reducing the risk of disabling dementia.
Current dog owners were found to have a 40% lower likelihood (odds ratio of 0.60 with a 95% confidence interval of 0.37–0.977) of suffering from disabling dementia when compared to those who had previously owned dogs or never owned them. In contrast, for cat owners, the odds ratio was 0.98 (with a 95% confidence interval of 0.62–1.55), indicating a negligible difference in dementia risk. Among current dog owners who also engaged in regular exercise, the odds of having disabling dementia were significantly lower by up to 63%, at an odds ratio of 0.37 (with a 95% confidence interval of 0.20–0.68), compared to past or never dog owners who did not have an exercise habit.
“Dog ownership had a suppressive effect on incident disabling dementia after adjusting for background factors during an approximately four-year follow-up period,” said Dr Taniguchi. He added that “dog owners with an exercise habit and no social isolation had a significantly lower risk of disabling dementia.”
Furthermore, the study concluded that caring for a dog encourages sustained physical activity and fosters consistent exercise habits. This aspect is particularly beneficial in promoting social engagement and healthy lifestyles, the study concluded.
Wrapping Up
Dog owners who regularly exercise and are not socially isolated are at the lowest risk of developing severe dementia. However, the research team cautions that merely owning a dog is not enough to ward off dementia if the owner leads a sedentary lifestyle with limited social interactions. The team emphasizes that positive effects in preventing dementia are not observed in dog owners who do not engage in daily activities related to dog care, such as exercise and socializing.
The study also highlights a cultural aspect, noting that the rates of dog and cat ownership in Japan are lower than those in Western countries, like the United States. This raises an interesting point for future research – to explore whether the patterns identified in Japan hold true in Western and other nations as well.
Globally, dementia is a significant health concern, as highlighted by the World Health Organization (WHO). Currently, around 50 million people are living with dementia worldwide, with nearly 10 million new cases diagnosed each year. This global prevalence underscores the importance of understanding all potential factors that could contribute to its prevention, including lifestyle choices like pet ownership and physical activity.
