10 Reasons Why Good Sleep Is Important

Sleep deprivation causes your body to release more of the stress hormone cortisol. Among many negative impacts, high levels of cortisol tell your body’s cells to store more fat. Additionally, a lack of sleep affects the release of the hormones which control our appetite: Ghrelin and leptin. These changes lead to us feeling more hungry more often, and less satisfied after consuming a meal.

Changes to our mood is one of the most apparent side-effects of suboptimal sleep, and many of us have first hand experience with irritability, increased frustration, and even symptoms of depression when overtired. Sleep plays an important role in our capacity to regulate positive and negative emotions and increases impulsivity. In fact, sleep deprivation actually lowers our responsiveness to emotional stimuli.

Sleep is absolutely essential for your brain to be able to function at an optimal level: Affecting everything from your ability to concentrate and solve problems, to your recall of important information. Memory consolidation — the process of moving information from our fleeting short-term memory to our long-term memory stores — takes place while we are asleep.

Chronically under-sleeping raises your risk of developing Type II diabetes by affecting how your body processes sugar. Research participants who were only permitted to sleep 4 hours per night for five nights experienced a 40% decrease in their levels of insulin — the hormone which regulates your body’s use of sugar.

Not getting enough sleep increasing the amount of inflammation you experience: Raising your risk for developing heart disease and diabetes, and exacerbating symptoms of inflammatory conditions such as arthritis. This increase in inflammation is due to a surge in your body’s production of inflammatory cytokines, alongside a reduction in inflammation-fighting proteins.

It turns out that the amount of sleep you get has just as much impact on sports performance as diet. Stanford researchers examined the effect of sleep on a group of Basketball players. The study showed that receiving adequate amounts of sleep improved the players’ speed, accuracy, reaction time and general feelings of well-being. In addition, sleep deprivation negatively impacts our metabolism.

While we sleep — and only while we sleep — our brains are literally flushed with fluid in order to remove waste products that build up throughout the day. These substances include beta-amyloid plaques which are infamously implicated in the development of neurodegenerative disorders, such as Alzheimer’s. This is why many sleep experts believe this cleaning function is the primary purpose of sleep.

Sleep is essential for our immune system to be able to fight off infections. Even partial sleep loss can greatly reduce the functioning of your immune system: Reducing your natural immune response, and lowering blood levels of infection fighting cells. Compared with people who have restricted sleep, those who received a full night’s rest had higher antibody counts in response to vaccination.

Both under-sleeping and oversleeping have been shown to negatively impact heart health. Chronic short sleepers are 48% more likely to develop or die from coronary heart disease. Meanwhile, those who spend too much time sleeping have a 38% increase in this risk. It’s believed that this is due to a disruption of the natural circadian rhythms causing issues with biorhythms, as well as chronic high levels of stress hormones.​

All of the things we’ve covered above contribute to increasing lifespan — but even independent of these factors, getting the right amount of sleep has been shown to improve longevity. A meta-analysis of sleep studies looked at the effect of hours of sleep on lifespan. This research revealed that sleeping less than 6 hours per night makes you 12% more likely to suffer a premature death; while sleeping more than 9 hours comes with a 30% increase in premature death.