How Sleep Affects Your Immune System
A good night’s slumber is “beauty sleep” for your immune system, too.
Research has shown that most of us need 7 to 9 hours of sleep every night to be at our best1]. That’s the optimum amount of time to repair, recharge and rejuvenate your mind, body and spirit.
But how does sleep affect your immune system? And, perhaps more importantly, what happens to your immune function if you don’t get enough rest?
In this article, we’ll explore the links between sleep and immunity, as well as looking at some tips for how to get more sleep while supporting your immune system.
The benefits of sleep for immune function
Great news for those who enjoy relaxing in bed; sleep is good for you. In fact, it’s believed that getting a good amount of rest can help with2]:
- Learning and memory
- Mental health and emotional wellbeing
And it also helps towards your immune function.
Like all armies, your immune system needs regular ready to attack at a moment’s notice. During sleep, your body produces cytokines, protective proteins that stimulate and coordinate white blood cell activity to fight infection and inflammation3].
So, we know that sleep does benefit your immune system. But what happens when you don’t get enough?
Sleep deprivation and the immune system
What mom used to tell you is true. A lack of sleep can make you sick.
Sleep deprivation and long periods of poor sleep are associated with lower immune system function and a reduced number of antibodies3 and killer cells4]. And that means you’re more at risk of falling ill. Studies show that sleep deprived people are more likely to become sick from a common cold virus5].
But the bad news doesn’t end there.
Research has also suggested that sleep deprivation may also increase the risk of heart disease related deaths. This is because of an increased level of inflammatory protein in the body, which may contribute to heart disease6].
Furthermore, other studies have identified a potential link between lack of sleep and the effectiveness of vaccines. These studies measured the antibody response to Hepatitis A7] and Hepatitis B8] vaccinations, and in both cases found that participants who had better sleep responded better to the vaccine, compared to those who were sleep deprived.
Better sleep: Helpful ways to nod off
It all seems clear cut, right? Lack of sleep can harm your health, so just get the regulation 7-9 hours to give yourself the best chance of being able to fight illness and infection.
Well, not quite.
For many people, sleeping is a little easier said than done. It’s believed that between 50 million and 70 million US adults suffer from sleep disorders6. And around 35% of Americans say their sleep is of a “poor” or “only fair” quality9].
Sleep experts stress the importance of establishing good night-time habits. If you’re one of the many who find sleep hard to come by, try these tips to help you get more Zs:
- Keep your bedroom cool and dark. Light can make you feel alert, so try blackout shades or a sleep mask to make your bedroom darker. Also regulate the temperature so that it’s not too warm that you’ll wake up during the night10]
- Establish a routine. Start winding down an hour before bedtime and write down anything you need to do the next day so it’s off your mind when you hit the sack
- Go to bed at the same time. Even on weekends, it’s best to stay on schedule to keep your circadian rhythm (body clock) consistent11]. Go to sleep and get up at the same time every day to improve your sleep
- Switch off your computer and cell phone. Bright screens that emit blue light interfere with melatonin production, the sleep hormone that signals your body to shut down12]. Try to avoid using tablet computers and phones in bed, and switch off the TV at least an hour before bed
- Cut the caffeine and stimulants. Coffee and other sources of caffeine are stimulants which remain active for several hours, so try to avoid consuming them in the hours before bedtime. Other stimulants like nicotine from cigarettes can have a similar effect, so cut down as much as possible to improve your sleep10
- Read a book. Rather than staring at blue light emitting screens, a good old book can help you unwind before bed and get your body into a familiar routine. E-readers are also fine, so long as they are not backlit with a harsh light13]
- Avoid alcohol. While you may initially find it easier to nod off after a few drinks, studies show that alcohol can disrupt the later parts of your sleep14]. Try to reduce your intake, and stop drinking a few hours before bedtime
- Eat a light bedtime snack. A snack consisting of complex carbs can help you drift off without weighing you down. Combine with tryptophan-rich foods such as milk, nuts or bananas to promote good sleep15]. Try a bowl of cereal or peanut butter on a slice of whole-wheat toast
- Relax, relax, relax. If you have trouble falling asleep, take deep, slow breaths, concentrating on the gentle rhythm of your chest rising and falling. Count backward from 100. Or focus on relaxing every inch of your body starting by uncurling your toes, loosening your legs and so on until you feel rested
These tips should help you create a better sleep hygiene routine, with the added benefit of supporting your immune system. If you continue to find sleep hard to come by, consider seeing your doctor, who may be able to help further.
*THESE STATEMENTS HAVE NOT BEEN EVALUATED BY THE FOOD AND DRUG ADMINISTRATION. THESE PRODUCTS ARE NOT INTENDED TO DIAGNOSE, TREAT, CURE OR PREVENT DISEASE
 Mayo Clinic (2016) How many hours of sleep are enough for good health?
 Harvard (Undated) Benefits of sleep
 NCBI (2012) Sleep and immune function
 NCBI (1996) Partial night sleep deprivation reduces natural killer and cellular immune responses in humans.
 Mayo Clinic (2015) Lack of sleep: Can it make you sick?
 WebMD (2010) Can Better Sleep Mean Catching Fewer Colds?
 NCBI (2003) Sleep enhances the human antibody response to hepatitis A vaccination.
 NCBI (2012) Sleep and Antibody Response to Hepatitis B Vaccination
 Sleep Foundation (2014) Lack of Sleep is Affecting Americans, Finds the National Sleep Foundation
 WebMD (2016) Sleep Disorders: 10 Tips to Get You Sleeping Again
 Sleep Foundation (Undated) What is Circadian Rhythm?
 NCBI (2012) Human melatonin and alerting response to blue-enriched light depend on a polymorphism in the clock gene PER3.
 Mayo Clinic (2017) Sleep tips: 6 steps to better sleep
 National Institute on Alcohol Abuse and Alcoholism (1998) Alcohol and Sleep
 WebMD (2017) Foods That Help or Harm Your Sleep