A team of researchers has found that sleep deprivation can lead to a less effective immune system. The team studied twins to see if lack of sleep affected any physiological processes. The findings are in a paper that was just published in the journal Sleep.
Sleep appears to be a critical activity and there are no animals that survive without some form of sleep. Even sharks, known for being on the move constantly, have their own sleep method. Interestingly, modern researchers have yet to identify the exact reasons we need sleep. One theory is that sleep forces animals to lay low for a while, potentially helping them avoid predators while conserving energy. Sleep deprivation can lead to problems with memory processing, injury healing, and hormonal imbalances; yet researchers have struggled to determine the actual causes behind these issues. In general, the functions of sleep are mostly unknown.
Scientists from the University of Washington School of Medicine conducted a twin study in response to a large number of anecdotes from people who mentioned getting sick more often when sleep-deprived. The team recruited 11 pairs of identical twins, allowing them to avoid any confounding variables such as genetics. Past studies had already showed that genetics play a large role in sleep patterns and sleep environment. The twins were monitored for two weeks while the research team collected data on sleep duration, gene expression, and blood tests.
The research team found that the twin who got less sleep had different patterns of gene expression. They also had lower white blood cell counts, cells that are extremely important in the immune response. The differences in gene expression resulted in the activation of inflammatory pathways in the twin with shorter sleep durations. Other genes failed to properly activate and circulate white blood cells, explaining the blood test results. This shows a clear link between sleep deprivation and a reduced immune response.
The team’s study shows that not getting enough sleep can result in a suppressed immune system. Since about one third of working Americans get less than six hours of sleep every night, this is a serious problem. Chronic sleep deprivation leads to immune system problems, making it more likely that those individuals will get sick. The authors recommend aiming for at least six hours of sleep a night.
Watson et al. Transcriptional Signatures of Sleep Duration Discordance in Monozygotic Twins. Sleep (2017).