Sleep Debts: Paying them off

Have you ever experienced a busy work week at least once in your life? I think most of us

can relate to this and most likely on a much deeper level. Is that morning, afternoon and

evening coffee really the only thing that is affecting us? Sleep debt, which is widely known

as sleep deficit, is defined as the cumulative effect of a person not having adequate sleep.

Studies such as Dr.Cavanaugh’s on chronic circadian misalignment resulting in reduced

longevity give us insight into what may actually be going on in terms of neurological changes

in the brain. This lack of sleep may be impacting our health in a way that we may have not

realized before. 

Even before seeing the results of Dr. Cavanaugh’s experiments, one can deduce that people need sleep and without it, there may be negative health consequences. To elucidate this some more, Dr. Cavanaugh conducted chronic circadian misalignment studies on flies(Drosophila). In the process of doing this, he put the flies into an activity manager tube where they could record sleep and activity by the fly passing through a laser beam. Then they exposed certain flies to light and dark shifts where they were able to misalign the sleep patterns of the flies. The results were stunning in the sense that the flies which experienced sleep deficits were dying about 15% earlier than those without circadian misalignment. Furthermore, to see what was happening on a genetic molecular level, they ran full-body RNA sequencing in order to see what genes were changed in the flies with the chronic circadian misalignment. The results were fascinating. Through their findings, they were able to show that the genes for oxidative stress as well as other factors that result in premature aging were upregulated. This may be the start of understanding the implicit factors that sleep debt has on our lifespan. 

A paper published by Harvard Medical School, explains to us why sleep is important and why we can’t live without it. Some tips that the paper mentions include avoiding caffeine in the afternoon, not taking naps during the day even if a shift worker because that can further misalign your sleep. One study that they conducted showed how students who only slept four hours a night for six nights had their immune system compromised, developed higher blood pressure and increased cortisol which is a stress hormone. After the study, the participants were required to take cognitive tests and the results showed that their response time decreased as well as their performance scores. 

Overall, these findings work together to show us how sleep deprivation may be decreasing our lifespan. On the range of a fly’s lifespan, 15% can be a few days while on a human lifespan that can equate to a few years. While our society moves further into the future we need to be conscious of the health impact on our shift workers who work all night in artificial lighting conditions. We need to take into account the genetic and cognitive outcomes that may result from prolonged sleep deficits. Assuming most people do not get enough REM sleep in their night, one may recommend tactics that were mentioned from the Harvard Medical School post in order to increase our sleeping hours and maybe even our lifespan. 

Cavanaugh, D. (2019, January 7). Chronic circadian misalignment results in reduced longevity and large-scale changes in gene expression in Drosophila. Retrieved from https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-018-5401-7

Harvard Health Publishing. (2018, June 18). Repaying your sleep debt. Retrieved from https://www.health.harvard.edu/womens-health/repaying-your-sleep-debt