Yes, poor sleep leaves you groggy, sluggish, and accident prone. But did you know that getting the recommended amount of sleep—7 to 8 hours a night—can boost your health, by building your immune system, protecting you from chronic diseases such as diabetes and heart disease, and speeding how quickly your body heals from injury.
Sleep regulates immune cell functions and the levels of antibodies, proteins that help the body fight off bacteria and viruses, according to a recent review in the European Journal of Physiology. That helps explain why a lack of sleep may make you more susceptible to the common cold. Other research suggests that a good night's sleep boosts the effectiveness of some vaccinations, while poor sleep reduces it.
Sleep may be as critical to good health as diet and exercise, according to the Centers for Disease Control and Prevention. Poor sleep has been linked to poor blood sugar regulation, inflammation, stress hormones, increased blood pressure, and clot formation. Those problems contribute to obesity, diabetes, and cardiovascular disease. Sleep helps balance your levels of the hormones ghrelin and leptin, which make you feel hungry or full.
Your body repairs itself while you sleep. That's when your body increases production of proteins needed for cell growth, including those in the heart and blood vessels, and to mend damage from stress and ultraviolet rays. While asleep, you release human growth hormone, which boosts muscle mass.
Getting ideal amounts of good sleep relieves stress and enhances mood, of course. But it also improves memory and concentration. Research suggests that sleep may help nerve cells repair themselves, and form new connections. There's even new evidence that during sleep, the brain clears away proteins and other cell waste byproducts that otherwise may interfere with mental function. Recent research, albeit animal studies, suggest that some of the proteins sleep helps clear away, called amyloid, might otherwise build up on the walls of the arteries in the brain and contribute to Alzheimer's disease progression.