Sleeping poorly could mean more than just being tired the next day — less sleep leads to a buildup of potentially harmful chemicals in our body. A good night’s sleep can help reduce these chemicals, known as inflammation, and make us feel better1,3,14. Scientific studies have shown that acute sleep loss in humans increases the levels of inflammation in the body9.
Additionally, sleep disturbances are associated with increased inflammation in the body, showing a link between dysregulated sleep and unhealthy chemical buildups4,9,7. Conversely, reducing inflammation in the body can result in a better night’s sleep. That means that inflammation and sleep are more interconnected than what you initially might think.
Poor sleep is a major contributing factor to harmful, chronic inflammation1, 12,8,10,5. Inflammation is not always harmful; in acute cases inflammation can increase our body’s ability to protect ourselves from invading bacteria and viral pathogens. However, lingering, chronic inflammation keeps the body’s immune system on high alert. When this happens for too long (it could be months or even years), it compromises the body’s biology11. In this compromised state, the body suffers disruptions to normal functions like sleeping well during the night11,1.
Sleep and immune response are both controlled by the circadian system, which is the internal, biological clock of the body2. Circadian rhythms regulate our sleep-wake cycles, telling us when we should be energized and alert, and when we should rest and recover from the day’s work2.
Recently, research has shown that the circadian system has a strong influence on how our body responds to inflammation1. When the circadian system undergoes a disruption either by a pathology or environmental changes (e.g., sleep disorder or time zones changes), the immune system is subsequently disrupted as well3. The byproduct of these disruptions is increased inflammation, which, if unsettled, can further disrupt circadian rhythms and further increase inflammation3.
As an example, cytotoxic T cells, a type of chemical response produced by the immune system to fight infections and cancers, can be stronger or weaker in attacking infections according to the time of the day2. Sleep and wake cycles are intimately tied to inflammation, and our overall bodily health2.
A study from 2010 observed that both severe sleep loss (where participants were awake for 24 hours or more) or partial sleep loss (participants were awake for around 20 hours) contributed to increased inflammation levels9. The researchers indexed the inflammation levels by tracking the amount of inflammatory cytokines (inflammatory cell signaling molecules) throughout the sleep restrictions. In all cases, the number of cytokines were increased9.
In a separate study, researchers demonstrated that “loss of sleep, even for a few short hours during the night, can prompt one’s immune system to turn against healthy tissue and organs8.”
Oversleeping is not harmless either. A meta-analysis (a study of multiple scientific studies) of over 70 studies which analyzed the correlations between sleep and inflammation, concluded that too much sleep (sleeping over 9 hours) also increases the levels of inflammation in the body7.
There are several things you can do to improve your sleep and thus improve your health.
Tip 1: Maintain a consistent sleep routine. Go to bed at the same time each day. Wake up at the same time each morning; use an alarm clock if you have to. This entrains the healthy circadian rhythms that dictate the functioning of both your sleep and immune system function to a regular cycle1.
Tip 2: To avoid inflammation and remain in good health you must get enough sleep every night. However, it’s not only important to get enough sleep but also keep a balance with sleeping and make sure you don’t oversleep. According to science, getting 7-8 hours of sleep each night is optimal12.
Tip 3: Pay attention to what you eat and drink during the day, and especially before bedtime. Stay hydrated; research suggests that even going to bed mildly dehydrated can disrupt sleep6. Avoid drinking too much alcohol before bed; while it’s okay to have a drink every now or then, it’s not okay to drink every night as that also disturbs sleep6. Caffeinated drinks have a disruptive effect as well6, so try to stop drinking them by early afternoon.
Tip 4: Have a healthy dinner a couple of hours before bedtime, but avoid foods that are rich in sugar and that could energize you or that may cause heartburn or flatulence, like broccoli, cauliflower, beans, cabbage, etc6,13.
Tip 5: A healthy, anti-inflammatory diet that combines fresh fruits, vegetables, nuts, seeds and avoidance of processed meat can help decrease inflammation. A healthy diet maintains a healthy gut, which is essential. Melatonin, a hormone that influences the sleep-wake cycle, is produced in the gut as well as the brain5.
Tip 6: Light Therapy, when coupled with other healthy sleeping and eating habits, can reduce inflammation in the body and result in a better night’s sleep. What’s more, for a lot of folks sleeplessness can be stressful. Light Therapy may work to relieve the inflammation and stress from sleep deprivation.