Do pets have a positive effect on your brain health?

"Prior studies have suggested that the human-animal bond may have health benefits like decreasing blood pressure and stress," said study author Tiffany Braley, MD, MS, of the University of Michigan Medical Center in Ann Arbor and a member of the American Academy of Neurology. "Our results suggest pet ownership may also be protective against cognitive decline."

The study looked at cognitive data from 1,369 older adults with an average age of 65 who had normal cognitive skills at the start of the study. A total of 53% owned pets, and 32% were long-term pet owners, defined as those who owned pets for five years or more. Of study participants, 88% were white, 7% were Black, 2% were Hispanic and 3% were of another ethnicity or race.

Researchers used data from the Health and Retirement Study, a large study of Medicare beneficiaries. In that study, people were given multiple cognitive tests. Researchers used those cognitive tests to develop a composite cognitive score for each person, ranging from zero to 27. The composite score included common tests of subtraction, numeric counting and word recall. Researchers then used participants' composite cognitive scores and estimated the associations between years of pet ownership and cognitive function.

Over six years, cognitive scores decreased at a slower rate in pet owners. This difference was strongest among long-term pet owners. Taking into account other factors known to affect cognitive function, the study showed that long-term pet owners, on average, had a cognitive composite score that was 1.2 points higher at six years compared to non-pet owners. The researchers also found that the cognitive benefits associated with longer pet ownership were stronger for Black adults, college-educated adults and men. Braley says more research is needed to further explore the possible reasons for these associations.

"As stress can negatively affect cognitive function, the potential stress-buffering effects of pet ownership could provide a plausible reason for our findings," said Braley. "A companion animal can also increase physical activity, which could benefit cognitive health. That said, more research is needed to confirm our results and identify underlying mechanisms for this association."

A limitation of the study was that length of pet ownership was assessed only at one time point, so information regarding ongoing pet ownership was unavailable.