A new Chinese study, published online in the journal General Psychiatry, has found that taking a regular afternoon nap could boost mental agility.

The study participants who had a regular nap were found to have “better locational awareness, verbal fluency, and working memory,” according to Science Daily.

Worldwide, at least one in 10 people above the age of 65 are affected by dementia and other associated neurodegenerative changes.

As the age progresses, our sleep patterns change, with afternoon naps becoming more frequent. However, studies published to date have not reached any consensus on whether afternoon naps help reverse cognitive decline or dementia in older people.

The study researchers looked at more than 2210 seemingly healthy people aged at least 60 and residents in several large cities in China.

Overall, more than 1500 participants took a regular afternoon nap, while 680 did not nap. The researchers assessed their health and cognitive function, including the Mini Mental State Exam (MMSE) to check for any memory loss or dementia.

In both groups, the average length of night-time sleep was around 6.5 hours. An afternoon nap is defined as periods of at least five consecutive minutes of sleep but does not exceed more than 2 hours, which is taken after lunch.

The researchers asked the participants how often they napped during the study period, which ranged from once a week to every day.

After analysis and evaluation, the team found that the “MMSE cognitive performance scores were significantly higher among the nappers than they were among those who didn’t nap.” In addition, there were significant differences in locational awareness, verbal fluency, and memory.

However, the study has a few limitations. For instance, it is an observational study, so it cannot establish a cause. Plus, there was no accurate information on the timing or duration of the naps taken.

The researchers said there are some possible explanations for the observations they found.

They said, “One theory is that inflammation is a mediator between mid-day naps and poor health outcomes; inflammatory chemicals have an important role in sleep disorders.”

“Sleep regulates the body’s immune response and napping is thought to be an evolved response to inflammation,” they added, “people with higher levels of inflammation also nap more often.” The article originally appeared in Science Daily.