Pet owners had slower rates of cognitive decline with age than people without pets. However, not all pets affected the brain in the same way: only owners of cats and dogs experienced better mental performance in old age, but not fish and birds. So having these animals may be one way to prevent dementia and Alzheimer's disease. Research published in the journal Scientific Reports.
Swiss researchers analyzed data from a European study that tracked the rate of cognitive decline in people aged 50 and over over the next 18 years. Nearly 40 percent of the study participants owned pets, so their scores were compared to those of people who did not own pets and to each other. Through interviews with the participants, the researchers measured their short- and long-term memory and their ability to recall as many words as possible, or fluency in speech.
As it turned out, the 1886 dog owners retained both types of memory better with age than the other groups of participants. At the same time, the 1778 cat owners retained their ability to express their thoughts better with age.
Scientists have several theories as to why owners of birds and fish did not experience such improvements in cognitive abilities. First, these animals live shorter lives, so owners may not have time to develop such close emotional bonds with them. Second, birds are more likely than other animals to make noise at night, which can lead to poorer sleep for their owners, which has been linked to faster cognitive decline. It is also possible that having fish or birds affects cognitive abilities that the researchers did not measure in this study, such as attention.
