A Good Night’s Sleep Recharges Immune System

THURSDAY, Sept. 22, 2022 (HealthDay News) -- If you want to stay well, make sure you're getting enough sleep.

That's the conclusion of a new study that found that good sleep helps regulate a key component of the body’s immune system.

Specifically, it influences the environment where white blood cells known as monocytes form, develop and get ready to support the immune function, a process called hematopoiesis.

“What we are learning is that sleep modulates the production of cells that are the protagonists – the main actors – of inflammation,” said senior study author Filip Swirski, director of the Cardiovascular Research Institute at Icahn School of Medicine at Mount Sinai, in New York City. “Good quality sleep reduces that inflammatory burden.”

The researchers studied the impact of sleep in a clinical trial of 14 adults. Each participant was assigned to get either 7.5 hours of sleep each night for six weeks or to get about six hours of sleep each night. Then they had six weeks of a “wash-out” period where they got their normal amount of sleep before being assigned to the opposite schedule for another six weeks.

The researchers collected morning and afternoon blood samples in the fifth and sixth weeks of both parts of the study.

What did they find? When the adults did not get enough sleep, they had higher levels of circulating monocytes in the afternoon, higher numbers of immune stem cells in the blood, and evidence of immune activation.

“The stem cells have been imprinted, or genetically altered, under the influence of sleep restriction,” Swirski said. “The change isn’t permanent, but they continue to self-replicate at a higher rate for weeks.”

This higher production of immune cells can speed the development of an age-related condition known as clonal hematopoiesis, which in turn is linked to an increased risk of cardiovascular disease.

The study, published Sept. 21 in the Journal of Experimental Medicine, was funded by the U.S. National Institutes of Health (NIH).

“Sleep impacts optimal functioning of nearly every cell and organ in the body,” said Marishka Brown, director of the National Center on Sleep Disorders Research at the NIH. “The mechanistic insight from this study supports findings from larger population studies, which have shown that sleep can have a protective effect against a variety of conditions, including heart disease, cancer and dementia.”

Establishing sound sleep patterns early in life is important, the study authors said in an institute news release. Doing so may reduce the severity of inflammatory conditions, such as sepsis.

An adequate night’s sleep for most adults is seven to eight hours of uninterrupted sleep each night. Older adults need about seven to nine hours. Children aged 11 to 17 should get about eight to 10 hours nightly.

More information

The U.S. Centers for Disease Control and Prevention has tips for sleep hygiene.

SOURCE: U.S. National Institutes of Health, news release, Sept. 21, 2022