Sleep and Your Immune System

One of the things I find most fascinating about sleep is that everybody does it. And not just people. According to Wikipedia, mammals, birds, reptiles, amphibians, and some fish sleep. Researchers have even found insects and nematodes that sleep. Despite the ubiquity of sleep, the reason we need it is not obvious. According to the National Sleep Foundation, sleep is an active phase that includes important processing. But “exactly how this happens and why our bodies are programmed for such a long period of slumber is still somewhat of a mystery.” While we may not understand all the mysteries of sleep, however, there is one thing we do understand: it is vital to a healthy immune system. This is the fourth installment of our eight-week survey: sleep and your immune system.

Sleep Supports T Cells

Stress hormones inhibit the function of some immune cells. We saw that in our look at stress a few weeks ago. Furthermore, a 2019 study shows that stress hormones are at their lowest level during sleep, which is why immune cells are more effective then. The researchers divided volunteers into two groups. One group slept and the other group didn’t. They examined the volunteers’ T cells, which play a central role in immune response. The T cells of the group that slept were more active and healthier than those of the group that stayed awake.

Perhaps it says something significant that the most practical research I found on sleep and the immune system was reported in a journal called Critical Care Nurse. Who knows better than nurses how a hospitalized patient’s healing can be delayed or undermined by a lack of sleep? It is a wide ranging article, but one of its goals was to suggest that intensive care units should better address the need for sleep. The article advised decreasing noise in the ICU by limiting use of televisions and telephones, keeping patients’ doors closed, and keeping conversations down. In addition, it suggested lowering ICU light levels, minimizing medications that inhibit sleep, and decreasing nighttime care activities such as bathing and dressing changes, all for the sake of better sleep. You might think about applying some of the same principles to your sleeping quarters.

Sleep and the Immune System

A review article from 2012 looked at sleep deprivation over time. It found that prolonged sleep deprivation causes a persistent production of pro-inflammatory cytokines, which is a chronic low-grade inflammation. It also cited research that found “The immune response to vaccination against influenza virus was diminished after 6 days of restricted sleep.”

So you can help to maximize your immune system by finding out what is keeping you awake at night and dealing with it. First, make sure you have a cool, dark environment to sleep in. Then manage your stress. Finally, practice good sleep hygiene. If you’re unsure what constitutes good sleep hygiene, Michael Breus’s “5 Steps for Better Rest” might be a good place to start. Breus is a popular psychologist who specializes in sleep disorders and maintains a website from which he dispenses practical advice and promotes his products.

The Real Cause of Insomnia

There are lots of things that can keep you awake at night. Some of the most common causes of insomnia — after stress — are irregular sleep patterns, use of caffeine or nicotine late in the day, exercising too soon before bedtime, eating a heavy meal before bedtime, or using a screen (phone, pad, computer, or television) right before bed. However, note that these obstacles to sleep are nearly always the result of giving insufficient priority to sleeping. That is the real cause of most insomnia. Unfortunately, the current Covid-19 siege is not a good time to be having problems with your sleep.

Prioritize your sleep. Your health depends on it. Now more than ever.