The Effects on Sleep Deprivation

 Written by: Kelly Douglass; SLU Dietetic Intern

        Adequate sleep is an essential component of health that is often sacrificed in the name of productivity. We commonly use willpower to help us overcome the side-effects of sleep deprivation in the short-term. But few people realize that long-term sleep deprivation has effects on the body that go beyond fatigue and loss of focus. Rather, it can lead to systemic physiological changes that affect our immune system, appetite, and overall risk for developing various diseases. Let’s dive deeper into why.

       1. Decreased Immunity

        The immune system is a cooperative symphony of cells, tissues, organs, and proteins that work together to help the body fight infections and other diseases. Research shows that the immune system response is greatly affected by the time of day. This indicates that circadian rhythm plays a key role in the functioning of our immune system.

        Sleep deprivation negatively alters our circadian rhythm. This affects processes of the immune response that include leukocyte mobilization and trafficking, chemotaxis, cytokine release, and T cell differentiation (Haspel). In simpler terms, the immune response is less effective in an environment of sleep deprivation. This phenomenon was observed in another study where 153 subjects were split into groups based on their reported sleep quality (time in bed vs. actual time asleep) and duration over 14 consecutive days. The groups were then equally exposed to rhinovirus (a.k.a the common cold) via droplets directly administered to their nostrils. The results of the study showed that those with <7 hours sleep had a 2.94 times greater likelihood of developing a cold than those with ≥ 8 hours of sleep. Those who scored < 92% for sleep quality had a 5.50 times greater likelihood of developing a cold than those with a sleep quality score of ≥ 98%. Therefore, sleep quality and sleep duration directly influences our resistance to illness (Cohen).

       2. Appetite Dysregulation

        Sleep has a direct impact on our hormone levels. Two of those hormones being leptin and ghrelin. These hormones are responsible for regulating our appetite because ghrelin increases hunger and leptin decreases hunger. Research has shown that those with shorter sleep have reduced leptin and elevated ghrelin levels. One study found that habitual sleep around 5 hours per night produced 15.5% lower leptin and 14.9% higher ghrelin than for those getting around 8 hours of habitual sleep. These changes in our hormone levels increase appetite and are associated with having a higher BMI. Therefore, it is important to get enough sleep to keep our appetite’s hunger and fullness cues accurate, helping us to more easily maintain a healthy weight (Taheri).

       3. Increased Risk of Disease

        Chronic sleep deprivation has systemic consequences on our physiology. One major result is an increase in inflammation. This is reflected in having higher circulating cytokines, interleukin-6, C-reactive protein which is a marker of inflammation that is commonly elevated in people at risk for heart disease and diabetes. We also know that stress hormones, like cortisol, rise during sleep deprivation which contribute to higher inflammation as well. This higher inflammation is linked to a greater risk of developing cardio­vascular disease, high blood pressure, and diabetes. We can also deduce that sleep deprivation increases the risk of obesity from what we have already described about its link to increased appetite via leptin and ghrelin dysregulation (Harvard Health).

        So how do we ensure we get enough sleep to protect our day to day sanity and our overall long-term health? From the experience of a graduate student, I can say that it is most important to remember that rest is not the same as distraction. Rest is productive! Without it, we can not function at our best. Next, I would be honest with myself about how much sleep I really need to feel good and plan for it. Some people feel great on 6-7 hours of sleep and others need 8-10 hours. For example, I am someone who needs at least 8-9 hours of sleep to feel good in the morning and, during times of extreme stress, I may need more. One person’s needs are not more or less justified than another’s. Finally, I would eliminate bright light and technology at least 1 hour before bedtime to help the mind wind down since we know that bright blue light from our phones decreases melatonin production. Try these tips for yourself and rest assured that you are helping your health in more ways than one when you prioritize your sleep.

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