Unexpected Benefits of Melatonin
Melatonin is best known as the “sleeping hormone” that helps regulate your circadian rhythm to support your natural sleep cycle. But that’s not all melatonin does for your body. Melatonin also plays a role in your metabolic health, gut health, and reproductive health, and may have benefits for healthy aging. Here are some of the benefits of melatonin that you might not know about:
Melatonin is a Powerful Antioxidant
Melatonin is an unexpectedly versatile and effective antioxidant that helps protect against oxidative stress through multiple pathways. It’s a potent free radical scavenger and also supports the body’s own antioxidant defenses.[1][2] Oxidative stress can cause damage to cells, tissues, and DNA, contributing to aging and negatively impacting health and wellness.
Melatonin is one of the select antioxidants that can cross the blood-brain barrier to help protect the brain from oxidative stress, which is important for healthy brain aging. Melatonin is also highly concentrated in the mitochondria, the powerhouses of your cells, where it helps protect mitochondrial health.[3] Loss of healthy mitochondrial function through oxidative stress is another key factor in the aging process. All this suggests that melatonin plays an important role in healthy aging.
Melatonin Supports Gut Health
Here’s a fun fact: there’s 400 times more melatonin in your gut than in your brain.[4] Melatonin is produced by cells in the gut mucosal barrier and is released in response to eating. Melatonin in the gut helps regulate gastrointestinal motility and supports the gut mucosal barrier by helping to regulate immune and inflammatory responses and protect against oxidative damage.[5]
Melatonin is now being studied for its potential digestive health benefits. Current research suggests that melatonin may be effective for helping to manage acid reflux[6] and reducing recurrent abdominal discomfort.[7]
Melatonin Supports Reproductive Health
Melatonin appears to have benefits for women’s fertility. It plays an important role in regulating the secretion of female reproductive hormones that govern the menstrual cycle,[8] which is crucial for normal ovulation. Melatonin is also found in high levels in the ovaries, where it is thought to provide antioxidant protection for eggs.
Studies done in women undergoing IVF treatments have found that those who have higher levels of melatonin have better egg quality and a better chance of successful implantation.[9] Other studies have found that taking melatonin during fertility treatments may help improve egg quality and boost fertilization rates.[10]
Melatonin May Support Heart Health
Melatonin’s antioxidant benefits and its influence on the circadian rhythm may have protective benefits for heart health. Circadian rhythms play a role in regulating blood pressure and blood sugar levels, while antioxidants help protect blood vessels from oxidative damage. Research shows a link between low blood levels of melatonin and a higher risk of heart health problems.[11][12]
Taking melatonin regularly before bed has been shown to help manage nighttime blood pressure for those with high blood pressure.[13][14] Melatonin also appears to play a role in regulating energy metabolism, including blood sugar balance. Low levels of melatonin are linked with a higher risk of blood sugar imbalances.[15] A recent systematic review of randomized controlled trials concluded that taking melatonin may help with blood sugar management.[16]
Keep in mind that this research is still developing. Melatonin may also interact with other medications taken for blood pressure or blood sugar, so be sure to talk to your doctor before adding it to your regimen.
Supporting Your Melatonin Levels
Melatonin is a hormone that’s naturally produced in the body in response to changes in the light. Getting exposure to natural light during the day and to darkness at night is important for regulating your circadian rhythms and triggering the natural production of melatonin. However, melatonin production can easily be disrupted by nighttime work shifts, travel and jet lag, or exposure to blue light from electronic screens at night. Melatonin production also naturally decreases with age.
You can boost your melatonin levels by sticking to a healthy bedtime and avoiding screen time at night, using nighttime light settings on your phone or computer, or wearing blue light-blocking glasses. You can also take melatonin as a supplement. Melatonin supplements are generally considered safe, but keep in mind that melatonin is a hormone, so more isn’t necessarily better. It’s generally advised to start with the lowest dose and then gradually increase if needed to fine-tune the right dose for you. Talk to your doctor if you are interested in making melatonin supplements a part of your routine.
References:
[1] Galano A, Tan DX, Reiter RJ. Melatonin: A Versatile Protector against Oxidative DNA Damage. Molecules. 2018 Feb 27;23(3):530. doi: 10.3390/molecules23030530. PMID: 29495460; PMCID: PMC6017920.
[2] Reiter RJ, Mayo JC, Tan DX, Sainz RM, Alatorre-Jimenez M, Qin L. Melatonin as an antioxidant: under promises but over delivers. J Pineal Res. 2016 Oct;61(3):253-78. doi: 10.1111/jpi.12360. Epub 2016 Sep 1. PMID: 27500468.
[3] Tan DX, Manchester LC, Qin L, Reiter RJ. Melatonin: A Mitochondrial Targeting Molecule Involving Mitochondrial Protection and Dynamics. Int J Mol Sci. 2016 Dec 16;17(12):2124. doi: 10.3390/ijms17122124. PMID: 27999288; PMCID: PMC5187924.
[4] Chen CQ, Fichna J, Bashashati M, Li YY, Storr M. Distribution, function and physiological role of melatonin in the lower gut. World J Gastroenterol. 2011 Sep 14;17(34):3888-98. doi: 10.3748/wjg.v17.i34.3888. PMID: 22025877; PMCID: PMC3198018.
[5] Vaghari-Tabari M, Moein S, Alipourian A, Qujeq D, Malakoti F, Alemi F, Yousefi B, Khazaie S. Melatonin and inflammatory bowel disease: From basic mechanisms to clinical application. Biochimie. 2023 Jun;209:20-36. doi: 10.1016/j.biochi.2022.12.007. Epub 2022 Dec 17. PMID: 36535545.
[6] Kandil TS, Mousa AA, El-Gendy AA, Abbas AM. The potential therapeutic effect of melatonin in Gastro-Esophageal Reflux Disease. BMC Gastroenterol. 2010 Jan 18;10:7. doi: 10.1186/1471-230X-10-7. PMID: 20082715; PMCID: PMC2821302.
[7] Siah KT, Wong RK, Ho KY. Melatonin for the treatment of irritable bowel syndrome. World J Gastroenterol. 2014 Mar 14;20(10):2492-8. doi: 10.3748/wjg.v20.i10.2492. PMID: 24627586; PMCID: PMC3949259.
[8] Bódis J, Koppán M, Kornya L, Tinneberg HR, Török A. Influence of melatonin on basal and gonadotropin-stimulated progesterone and estradiol secretion of cultured human granulosa cells and in the superfused granulosa cell system. Gynecol Obstet Invest. 2001;52(3):198-202. doi: 10.1159/000052973. PMID: 11598364.
[9] Tong J, Sheng S, Sun Y, Li H, Li WP, Zhang C, Chen ZJ. Melatonin levels in follicular fluid as markers for IVF outcomes and predicting ovarian reserve. Reproduction. 2017 Apr 1;153(4):443-51.
[10] Espino J, Macedo M, Lozano G, Ortiz Á, Rodríguez C, Rodríguez AB, Bejarano I. Impact of Melatonin Supplementation in Women with Unexplained Infertility Undergoing Fertility Treatment. Antioxidants (Basel). 2019 Aug 23;8(9):338. doi: 10.3390/antiox8090338. PMID: 31450726; PMCID: PMC6769719.
[11] Alberto Dominguez-Rodriguez, Pedro Abreu-Gonzalez, Pablo Avanzas. The role of melatonin in acute myocardial infarction. Front. Biosci. (Landmark Ed) 2012, 17(7), 2433–2441. https://doi.org/10.2741/4063
[12] Dominguez-Rodriguez A, Abreu-Gonzalez P, Sanchez-Sanchez JJ, Kaski JC, Reiter RJ. Melatonin and circadian biology in human cardiovascular disease. J Pineal Res. 2010 Aug;49(1):14-22. doi: 10.1111/j.1600-079X.2010.00773.x. Epub 2010 Jun 1. PMID: 20536686.
[13] Frank A.J.L. Scheer, Gert A. Van Montfrans, Eus J.W. van Someren, Gideon Mairuhu, and Ruud M. Buijs. Daily Nighttime Melatonin Reduces Blood Pressure in Male Patients With Essential Hypertension. Hypertension, Volume 43, Issue 2, 1 February 2004; Pages 192-197. https://doi.org/10.1161/01.HYP.0000113293.15186.3b
[14] Angelo Cagnacci and others, Prolonged Melatonin Administration Decreases Nocturnal Blood Pressure in Women, American Journal of Hypertension, Volume 18, Issue 12, December 2005, Pages 1614–1618, https://doi.org/10.1016/j.amjhyper.2005.05.008
[15] McMullan CJ, Schernhammer ES, Rimm EB, Hu FB, Forman JP. Melatonin secretion and the incidence of type 2 diabetes. JAMA. 2013 Apr 3;309(13):1388-96. doi: 10.1001/jama.2013.2710. PMID: 23549584; PMCID: PMC3804914.
[16] Doosti-Irani A, Ostadmohammadi V, Mirhosseini N, Mansournia MA, Reiter RJ, Kashanian M, Rahimi M, Razavi M, Asemi Z. The Effects of Melatonin Supplementation on Glycemic Control: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Horm Metab Res. 2018 Nov;50(11):783-790. doi: 10.1055/a-0752-8462. Epub 2018 Nov 5. Erratum in: Horm Metab Res. 2018 Nov;50(11):e6. PMID: 30396207.