Japanese Study Finds Dog Owners Have 40% Lower Dementia Risk, While Cats Show Minimal Impact

Many individuals are already familiar with the positive impact of dog ownership on mental health, including the reduction of stress, depression, and loneliness. However, a recent study from Japan ^[1]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10583170/ has unveiled an additional benefit: owning a dog can significantly decrease the likelihood of dementia in adults aged 65 and older, a cognitive condition affecting over 55 million people globally, by up to 40 percent.

Conducted by a research team from the Tokyo Metropolitan Institute for Geriatrics and Gerontology, the study surveyed over 11,000 individuals between the ages of 65 and 84. Participants were queried about pet ownership—specifically whether they owned cats, dogs, or had no pets—and the types of exercise they engaged in regularly, such as walking, running, yoga, swimming, and cycling. After a four-year period, researchers reevaluated participants’ health conditions and monitored the development of any dementia symptoms.

The researchers quantified the risk of developing dementia using an “odds ratio.” Dog owners were found to have a calculated risk of 0.6, while cat owners had a risk of 0.98, and those without dogs or cats were at 1.0 risk.

The study revealed that dog owners were more likely to engage in regular outdoor activities, leading to increased social interactions—an essential factor with a “suppressive effect” on dementia. Moreover, the heightened physical activity associated with dog ownership was found to reduce the abnormal accumulation of proteins in the brain, a phenomenon observed in dementia patients. Additionally, exercise promoted better blood flow to the brain and stimulated cell growth and survival.

The study’s authors emphasized, “Dog ownership had a suppressive effect on incident disabling dementia after adjusting for background factors during an approximately four-year follow-up period.” They highlighted that dog owners with an exercise routine and no social isolation exhibited a significantly lower risk of disabling dementia.

In conclusion, the study suggested that caring for a dog contributes to the maintenance of physical activity, including regular exercise, and fosters social participation—even during circumstances like the Covid-19 pandemic, which imposed restrictions on social interactions.