Staying up late is nothing new to us. Whether it’s out having fun with friends or crunching out assignments for work, many of us get less than the optimal hours of shut-eye. But what’s the big deal? We’ll only be a little lethargic and grouchy – a hot coffee is the obvious solution, right? The caffeine blocking adenosine receptors only makes you feel less tired, and the consequences run deeper than you think.
Ever had a hard time remembering things after a sleepless night? It has been known for a while that sleep functions to consolidate and stabilize declarative memory, or your ability to remember facts. Recent studies have actually pinpointed this phenomenon to a stage of sleep known as NREM SWS sleep, or non-rapid eye movement slow wave sleep. This is the stage of sleep you enter within the first few hours of falling asleep, and is characterized by no movement of the eyes and low frequency brain waves. It turns out that the more NREM SWS sleep you get, the better your declarative memory retention.
Sleep deprivation can lead to things much worse than just forgetting to buy milk from the store. Societal catastrophes, such as the Chernobyl nuclear disaster and the Exxon Valdez oil spill, have all been linked to workers who didn’t get enough sleep. On January 2006 in Union County, Florida, a school bus transporting nine children and a Pontiac Bonneville carrying seven occupants were hit by an 18-wheel freight truck that failed to stop. All of the passengers in the Bonneville and the bus driver were killed on-site, and the children sustained serious injuries. Five of the seven passengers in the Bonneville were children or adolescents, with the youngest being a 20-month old infant.
Short duration of sleep is also linked to lower antibody production and decreased natural killer (NK) cells, aspects of your immune system critical for staving off potentially deadly infections. Furthermore, it is also associated with the production of reactive oxygen species, which can damage DNA and cause cancer. In fact, a study in 2011 by Thompson et al. showed a direct association between sleep deprivation and colorectal adenoma.
Medical residents are commonly known to be sleep deprived, often getting four hours of sleep or less. This can spell disaster for their patients: a study by Baldwin and Dougherty in 2004 found that 45% of residents who slept less than four hours reported at least one error during their shift. They found that 1 in 5 residents seriously harm a patient due to fatigue-related errors, and 1 in 20 will kill a patient for this reason. With around 26,000 residents in training in the U.S., that’s more than a thousand deaths every year. You could be the one perfectly well rested, and still fall victim to sleep deprivation. Frightening.
Source: Matthew Walker, Psychology of Sleep, UC Berkeley