Researchers found that a daytime nap could slow down the rate of brain shrinkage as we age.

The data collected from people aged between 40 and 69 years old was analyzed and it was found that regular napping is associated with greater brain volume. This indicates a healthy brain function, and can reduce the risk of dementia and other conditions.

These results suggest that short daytime naps could be beneficial for some people as they age.

Studies have shown that napping can improve cognitive performance. Individuals who napped for a short time outperformed those who did not nap during cognitive tests conducted hours after napping.

The current study aimed to determine whether there was an association between daytime napping and brain health.

The method of Mendelian Randomization was used to examine 97 DNA fragments that are thought to be responsible for determining a person’s tendency to nap. The UK Biobank study compared the cognitive and brain health of people who were genetically more predisposed to napping with those without this genetic variant.

It was estimated that the average difference in brain volume between people who were predetermined as regular nappers, and those who weren’t, was equal to 2.6-6.5 years of age.

However, there was no difference in the performance of individuals who were predetermined as regular nappers on three other measures of brain function and cognitive function, including visual processing, hippocampal size, and reaction time.

This study aimed to determine the causal relationship between daytime napping patterns and brain structural and cognitive outcomes. Mendelian randomization examines genes that are determined at birth, which reduces the chance of confounding factors occurring during life to influence daytime napping.

The study indicates a causal relationship between napping regularly and a larger total brain volume.

In a previous research, 452,633 participants in the UK Biobank Study were examined to determine the genetic variants that influence napping. The variants were identified using self-reported napping and objective physical activity measures recorded by an accelerometer on the wrist.

The current study examined cognition and health outcomes of individuals with these genetic variants. It also included a variety of subsets that were adjusted to avoid bias. For example, variants linked with excessive daytime sleeping were avoided.

The UK Biobank Study included a larger sample of 35,080 individuals who were able to access their MRI brain scans as well as genetic data.

The study was limited by the fact that all the participants were white Europeans. Therefore, the results might not be applicable to other ethnicities.

Researchers did not have data about the length of naps. However, previous research indicates that naps lasting 30 minutes or less are the most beneficial for cognitive health. Naps taken in the morning will also likely disrupt sleep at night.