Science Said 'Yes' to Nap Time for Adults

Napping may reverse hormonal and immune system effects of sleep deprivation

(RxWiki News) Babies and toddlers are expert nappers, but perhaps tired and stressed adults should pencil in some nap time, too!

Lack of sleep is known to cause fatigue and problems with thinking and memory, but it may also result in hormonal and immune system changes. A new study found that napping may reverse these changes in adults.

“Napping may offer a way to counter the damaging effects of sleep restriction by helping the immune and neuroendocrine systems to recover,” said senior author Brice Faraut, PhD, of the Université Paris Descartes-Sorbonne Paris Cité in France, in a press release. “The findings support the development of practical strategies for addressing chronically sleep-deprived populations, such as night and shift workers.”

Past research has found that sleep deprivation may cause changes in body chemistry. Prolonged lack of sleep has even been linked to heart problems. To see just how much napping helped the body recover, Dr. Faraut and team looked at the effect of naps on body chemistry.

For this study, 11 healthy adult male volunteers spent the night in a sleep lab, where they were only allowed to sleep for two hours. The next day, they were then allowed either no naps or two 30-minute naps. The next night, they could sleep as much as they wanted.

Dr. Faraut and colleagues measured various hormone and immune system substances in these patients to see how they differed during normal sleep, restricted sleep and restricted sleep with naps.

They found that sleep restriction led to a 2.5-fold increase in norepinephrine levels. However, taking two 30-minute naps erased this change. Norepinephrine is a hormone tied to stress. Dr. Faraut and colleagues theorized that napping had a stress-relieving effect.

Napping also appeared to restore immune system function in those who only had restricted sleep.

This study was published online Feb. 10 in the Journal of Clinical Endocrinology and Metabolism.

A grant from the mutual insurance company REUNICA and a postdoctoral fellowship from the Société Française de Recherche et de Médecine du Sommeil funded this research. Dr. Faraut and team disclosed no conflicts of interest.

Review Date: 
February 8, 2015