If you’ve ever had a bad night’s sleep, you know how nearly everything in your life suffers the next day. Simple chores suddenly feel like massive tasks, you’re more on edge in situations that normally wouldn’t bother you much, and you might be tempted to reach for a caffeinated beverage or sugary treat to get you through a mentally foggy morning.
Underlying good sleep is a hormone called melatonin. Synthesized in the pineal gland, melatonin is secreted in a circadian pattern, with the highest amounts released during nighttime. When the sun begins setting, declining levels of light signals a chemical cascade that triggers the secretion of melatonin. Levels of this hormone rise almost 10-fold at night, telling the body to unwind. Sunlight the following morning then suppresses melatonin levels. 1
400 times more melatonin is produced in the gut than in the brain, where it serves to balance inflammation and acts as a powerful antioxidant.
While melatonin is rightly thought of as the sleep hormone, it does so much more than just regulate sleep patterns. This hormone is also involved in many regulatory processes, including metabolism, reproduction, and managing inflammation in the body. Melatonin can even help organs, such as the gut and liver communicate. In fact, 100 times more melatonin is produced in the gut than in the brain, where it serves to balance inflammation and acts as an antioxidant.
It is such a powerful anti-inflammatory and antioxidant, in fact, that it was found to not only protect the lungs of mice in a SARS model from ARDS (Acute Respiratory Distress Syndrome), but also help the immune response during lung infection and heal lung damage in this animal model of infection. 2
Melatonin production varies according to the season and availability of light. Depending on where you live, that means producing this hormone for a longer period in the winter than in the summer. 3 However, as you get older, melatonin production gradually declines. This can reduce the quality of your sleep, but decreased melatonin production with age is also associated with a decline in cognitive abilities like thinking and social functioning.
Reduced amounts of melatonin have been attributed to a number of disorders, including sleep disorders and jet lag.
Recent studies have even found diminished production of melatonin at the very early stages of Alzheimer’s disease, providing new insight about new ways to manage this cruel disease. 4 We’re even seeing how melatonin can be beneficial for cancer patients. In clinical trials, melatonin has shown some promise to increase the efficacy of cancer chemotherapy and improve survival. Several studies have also shown that melatonin reduces the adverse toxicities of chemotherapy and radiation therapy.
Melatonin, Sleep, and Circadian Rhythms.
If you’ve read our previous blog post on how to step up the immune system , then you know that the quality and quantity of your sleep affects your immune system. The less sleep you get, the more prone to infection you become.
Having sufficient amounts of melatonin can support a healthy circadian rhythm. Your circadian cycle responds to light and darkness to alternate alertness with sleepiness. By circadian rhythm, I am referring to your biological clock — your body’s internal timer. This master clock controls the production of melatonin. When there is less light, the pineal gland in the brain is signaled to make more melatonin. As a result, you get drowsy. 5
Sleep Disturbances & Melatonin
Sleep disorders can come in many different forms, but underlying all of them is a diminished quality of life and wellbeing. Insomnia in any form, whether it’s difficulty falling asleep, staying asleep, or both, disturbs your body’s delicate internal rhythms. Anyone who has had a run of sleepless nights also knows that it leads to increased anxiety. Eventually, you may feel wired while feeling exhausted at the same time. This tired but wired feeling is what we discussed in a previous blog: “ Get Your Cortisol In Check .” It will also throw off your gut rhythm, leading to either constipation or diarrhea, and disrupt the natural circadian rhythm of your gut microbiome, leading to metabolic syndrome, insulin resistance, and weight gain.
Melatonin levels start to rise two hours before bedtime. That’s important to know, because most of you probably run your day like a marathon until the moment you decide to shut the lights and go to sleep. But, once you shut off the lights, you can’t get to sleep and you wonder why. Well, you can’t just push your body out of a race and expect it to wind down in just 5 minutes and fall asleep.
The Night Shift: Good or Bad?
Working the night shift is another major problem. The later you stay up, the more you crave something sweet or starchy. Your body is tired, and it wants quick energy to keep it going. By the next morning, the digestive system is out of sync, and eating can actually make you feel sick to your stomach.
Night shift work messes up your digestive system’s harmony and triggers sugar / carb cravings.
If you are a shift worker, unfortunately, some of this is out of your control. For most of us, though, the choice to have regular sleep times is ours to make. I cannot stress enough the importance of regular sleep patterns. Consistency is key, as the body and your gut microbiome like predictability.
If you’ve ever experienced jet lag, you know the feeling of having your circadian rhythm disrupted. If you fly from, say, Los Angeles to New York City, you will lose three hours because your body is running on west coast time. If you take a red eye and land at 7 a.m., your biological clock thinks it’s 4:00 a.m. This throws off the delicate internal rhythm of your enteric (gut) nervous system, which leads to problems such as constipation and poor digestion. All these issues are compounded by the dehydrating in-flight atmosphere.
Most of us are not traveling across time zones, but still struggle with healthy melatonin production. We are delicate biological systems, onto which all sorts of unnatural technologies have been introduced, which result in a disturbance in our innate ability to regulate our bodies in connection with the earth, sun and moon.
Melatonin and the Immune System
Melatonin is more than just a sleep hormone; it also has significant anti-inflammatory and antioxidant benefits. That makes melatonin a powerful ally for the immune system, where this hormone provides numerous benefits. Various species of animals and birds have melatonin receptors in a wide variety of organs and immune cells, and melatonin increases certain white blood cells, including the natural killer cells that are specialized to target and kill cells infected with viruses to prevent their spread to other neighboring cells. 6
During the winter, when we are usually exposed to less sunlight, we produce more melatonin. Studies have shown that increased melatonin production in the winter helps manage proinflammatory cytokines, which is beneficial to control the pathogens that can make you sick and support the immune system. Overproduction of melatonin –– along with less sunlight –– in the winter might account for the increased levels of fatigue, but also mood disorders such as depression and seasonal affective disorder (SAD). 7 8
As with all hormones, balance is key with melatonin. Declining levels of this hormone can also occur for many reasons, including age. Reduced levels can adversely impact the function of different immune cells. Age-related drops in melatonin production can also reduce important antioxidant protection in older individuals, contributing to or increasing the severity of some age-related diseases, such as Alzheimer’s disease. 9
Melatonin Is An “Immunological Buffer”
Researchers have labeled melatonin an “immunological buffer.” This hormone helps direct the chemical messengers that almost all immune cells produce, helping the immune system work more efficiently.
Melatonin also helps manage free radicals. Typically, the body has powerful antioxidant defense systems to fight these free radicals. When they accumulate beyond the body’s capacity to manage them, a condition called oxidative stress occurs. This can overwhelm the body’s antioxidant defenses and create disease.
Melatonin works with both acute and chronic immune responses. In conditions that require an early immune response against external stressors, such as viruses and parasites, melatonin can help stimulate the immune system. In others that create a long-term immune response like chronic infections, melatonin performs as an anti-inflammatory molecule. 10 Like oxidative stress, chronic inflammation is a driver for nearly every disease.
Studies are showing that melatonin can help manage viral infections, such as Covid-19. Excessive inflammation, oxidative stress, and an exaggerated immune response all play a role in the development of the damaging consequences that many of us fear in relation to Covid-19 infection. The anti-inflammatory, antioxidant, and immune-regulating protection of melatonin can help limit virus-related damage, such as that caused by Covid-19. Not surprisingly, a recent study showed that melatonin can help reduce anxiety, improve sleep quality, and lead to better clinical outcomes for COVID-19 patients. 11
Melatonin & Gut Health
When you think about hormones such as melatonin, you probably see them as being manufactured in the brain. If you’ve read Happy Gut , you understand the enteric [gut’s] nervous system is in charge of producing many neurotransmitters. While the pineal gland is most famous for secreting melatonin, the gut contains at least 400 times more melatonin than the pineal gland. The concentration of melatonin in the gut, in fact, surpasses blood levels by 10 – 100 times. 12 Outside the pineal gland, the intestine is the major site for melatonin production.
Melatonin exerts its effects through specific membrane receptors, named melatonin-1 (MT1), MT2 and MT3 receptors. These receptors are located at different sites throughout the body. The MT3 receptor, for instance, is located in liver, kidney, heart, lung, intestine, muscle and brown fat tissue.. Studies have shown these receptors are involved in regulating motility, inflammation, and pain within the gut. 14
As an antioxidant, melatonin provides a wide range of gut support, including regulating the inner lining of the intestinal tract, called the intestinal mucosa. Melatonin protects the gastric mucosa from damage that pain relievers called nonsteroidal anti-inflammatory drugs (NSAIDs) can cause . Melatonin also helps regulate the little energy factories found within nearly every cell, called mitochondria. 15
In addition, this wide-ranging hormone helps manage immune functions throughout the gut. In animal studies, it has been shown to protect against intestinal inflammation. 16 Animal studies have also shown that small doses of melatonin increase intestinal motility. 17
Sleep and the gut are intimately interrelated. An unhealthy gut can impede circadian rhythms, altering the body’s sleep-wake cycle and impacting sleep-regulating hormones, such as melatonin. Conversely, the quality of sleep can impact the diversity and quality of the gut microbiome. 18 Interrupted circadian rhythms in the colon impact the gut in several ways. They have been linked to digestive problems, including gas, and constipation. I’ve written more about the sleep-gut connection in this blog.
Low melatonin production can also lead to leaky gut.
Studies have shown that decreased levels of melatonin heighten the risk of increased intestinal permeability and endotoxemia. 19 As a result, things not intended to slip through the gut wall augmenting the immune response and inflammation throughout the body.
Reduced levels of melatonin have been connected to irritable bowel syndrome or IBS. Studies involving patients with IBS found that melatonin relieves symptoms such as abdominal pain and abdominal distension. Melatonin could be a future therapeutic option, in fact, for IBS management. In one placebo-controlled, randomized clinical trial in 40 patients with IBS, taking 3 mg of melatonin orally at bedtime for two weeks significantly alleviated abdominal pain. 20
5 Ways to Support the Production of Melatonin
Melatonin is best known as the sleep hormone, but as you’ve seen, its anti-inflammatory, immune-supporting, and antioxidant benefits make this a key hormone for gut and immune health. While a supplement before bed can help support melatonin levels, the best way to maintain optimal levels of this hormone is by supporting the body’s natural production. These five strategies support healthy melatonin production at any age.
- Limit blue light at night. Until artificial lighting was invented, the sun was our major source of light. We spent the evenings in almost total darkness. Obviously, that’s not the case today as screen time –– TV, laptops, tablets, and phones –– trickles into the late evening hours for almost everyone. Blue light benefits us during the day, because it can improve your attention, mood, and how quickly you react to something. At night, however, blue light throws your circadian rhythm out of balance. As a result, sleep quality suffers, because blue light suppresses melatonin. Studies have shown that compared with green light, blue light suppresses melatonin for about twice as long and shifts circadian rhythms by twice as much. 21 To reduce the impact of blue light, consider using blue-blocking glasses near bedtime , use dim red light in the evening, and limit or eliminate electronics at least two hours before bed.
- Get some morning sunshine. Many of us spend our mornings inside, rushing from home to the office (even if lately, the office has been our home). As a result, we miss out on the morning sunlight that can optimize our levels of melatonin. Exposure to sunlight boosts the production of your feel-good neurotransmitter serotonin, which the body uses to make melatonin. Studies have shown that exposure to bright morning light reduces the likelihood of insomnia, premenstrual syndrome, and seasonal affective disorder (SAD). 22 You don’t need much. Even 10 – 15 minutes of natural sunlight in the morning can improve melatonin production and boost your mood throughout the day.
- Make more melatonin by healing your gut. An unhealthy gut results in lower production of melatonin, which will impede sleep levels, immune health, and overall well-being. Lower levels of melatonin, in turn, can damage the gut. When patients have trouble sleeping, I almost always start with the gut. Following the Happy Gut® Diet and using the Gut C.A.R.E. Program supplements will go a long way toward healing the gut. For a total gut reboot, check out the Happy Gut Reboot: 28-Day Cleanse.
- Eat foods high in melatonin. One way of indirectly increasing melatonin is by eating foods high in the amino acid tryptophan, which is a precursor for melatonin production. Studies have shown that eating melatonin-containing foods significantly increases levels of this hormone. Among animal foods, eggs and fish contain the amino acid tryptophan, which is a precursor for melatonin production. Among plant foods, nuts are highest in melatonin. Some kinds of mushrooms, germinated legumes, and seeds are also good sources of melatonin. 23
- Try fasting. Animal studies have shown that food restriction increases melatonin concentrations in the gut and in the brain, suggesting that fasting is yet another way to help increase melatonin production and get all of the other benefits of a healthy gut. 24
When it comes to detoxification, good sleep is critical. We know that brain detoxification happens while you sleep. 25 Melatonin plays a critical role in that process: Its antioxidant and anti-inflammatory benefits protect against damage to the brain, including damage to the little energy factories called mitochondria.
Animal studies have shown that melatonin directly scavenges free radicals and stimulates an enzyme called glutathione peroxidase, which produces the body’s superhero detox molecule, glutathione, to fight free radical damage in the brain and other organs. 26
While you might have considered melatonin as a sleep hormone, you can see now how this critical hormone also works as a powerful antioxidant, immune regulator, an anti-inflammatory, and so much more. Healthy levels of melatonin promote good sleep, but they also boost your immune system, keep the gut healthy, and support your overall well-being.
When your gut health suffers, so does the production of key hormones such as melatonin. As a result, your mood, immune health, weight, and happiness all take a hit. Keeping the gut healthy is especially critical during this stressful, uncertain time. The good news is that with these happy gut strategies, you can support a healthy gut and produce the optimal amount of hormones, including melatonin. As a result, you get great sleep, maintain a strong immune system, and cultivate an overall sense of happiness and wellbeing.