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Melatonin Research Update

melatonin molecule researchThe body produces the hormone melatonin in several places, mostly in the pineal gland and the eyes. It is also produced in the gastrointestinal tract, bone marrow, skin, and white blood cells known as lymphocytes. Melatonin coordinates circadian rhythms and helps induce sleep. Research suggests the decline in melatonin levels that occurs during aging contributes to insomnia and other aging-associated conditions.

Melatonin does more than assist in balancing our circadian rhythms. New research substantiates that it helps our vision.

Glaucoma/Eye Pressure

Intraocular pressure is usually lowest at night, which is also when natural melatonin levels are near their highest in the circadian cycle. IOP is highest in the morning when melatonin is low. There seems to be a correlation between IOP and melatonin; supplementing with melatonin may lower IOP.1 While most melatonin is created in the pineal gland, certain structures within the eyes synthesize melatonin. The cells of the ciliary body, which produce aqueous humor, contain receptors activated by melatonin.2 Melatonin improves the function of retinal ganglia, and in clinical research, researchers have discovered that personalized strategies for dosages are not only effective in maximizing the benefits. They also found that melatonin has benefits for sleep and circadian rhythms, especially for people with advanced glaucoma.3

Macular Degeneration

Researchers found that a combination of melatonin, zinc, and selenium, taken before bedtime, helped stabilize AMD with some remarkable improvement in the fundus of the eye after taking the combination for six months.4 5

Researchers have established that one of the causes of macular deterioration in AMD is due to poor mitochondrial respiration.  A recent study found that melatonin’s beneficial effect on mitochondrial function reduces oxidative stress, inflammation, and cell death in the retina.6

With respect to the link between vision and circadian rhythms, the eye is the primary recipient of circadian signals, and because melatonin regulates circadian rhythms, its benefits are noted in the retina as well. There are several mechanisms where melatonin plays a role: in mitochondrial function, where it behaves like a mitochondria-targeted antioxidant, and in supporting the integrity of telomeres which can be damaged by oxidative stress.  Telomeres are protective structures (formed from DNA and proteins) that are found at the end of chromosomes and are required for cell division.7

Poor Night Vision

A deficiency of melatonin could contribute to poor night vision. Photosensitive retinal ganglion cells interpret ambient light intensity. They are modulated by melatonin8 and contain melanopsin, which affects pupil dilation and dark adaption.9

Cataracts

In diabetic lab animals, melatonin has delayed the onset and progression of cataracts.10

Glutathione Production

Glutathione is an essential nutrient for vision.  It is considered a “super antioxidant” because it can help neutralize the full spectrum of different types of free radicals in one’s body. Researchers note that melatonin helps increase levels of glutathione in the body. 11

Blue Light

It is known that exposure to blue light inhibits melatonin production and that by blocking blue light through amber filters on our computers and sunglasses, we support natural melatonin synthesis. People who spend long hours on the computer without blue light protection, and those who spend long hours out of doors, such as hikers, skiers, fishermen, farmers, gardeners, etc. are exposed to lots of blue light, and melatonin supplementation is a good idea.

A little more …

Melatonin acts directly on ocular structures to normalize and support a range of visual processes. Researchers report that in addition to fighting glaucoma and AMD, melatonin may be a powerful tool to counteract other conditions such as uveitis12 diabetic retinopathy,13 optic neuritis 14, retinopathy, (15. Oliveira-Abreu K, Cipolla-Neto J, Leal-Cardoso JH. (2021). Effects of Melatonin on Diabetic Neuropathy and Retinopathy. Int J Mol Sci.
Dec 22;23(1):100.] and cell death due to oxidative stress in the eye.15

More about Melatonin

Read about how melatonin fights free radicals, supports the immune system, supports circadian rhythms, sleep patterns, and the brain, and reduces the risk of dementia and supports the sleep patterns of those with Alzheimer’s and Parkinson’s in our previous article: Melatonin: More than a Sleep Aid.

SUPPLEMENTS

Advanced Eye & Vision Support Formula (whole food) 60 vcapsReVision Formula (wild-crafted herbal formula) 2 oz

ACG Glutathione EXTRA STRENGTH Spray 2oz.

Melatonin (50) MZS 60 x 3mg Tabs – with selenium and zinc

Dr. Grossman’s REM Sleep Support (sublingual) Formula (with melatonin)

Footnotes

  1. Samples JR, Krause G, Lewy AJ. (1988). Effect of melatonin on intraocular pressure. Curr Eye Res. Jul;7(7):649-53. ↩
  2. Alkozi HA, Navarro G, Franco R, Pintor J. (2020). Melatonin and the control of intraocular pressure. Prog Retin Eye Res. Mar;75:100798. ↩
  3. Gubin D, Neroev V, Malishevskaya T, Cornelissen G, Astakhov SY, et al. (2021). Melatonin mitigates disrupted circadian rhythms, lowers intraocular pressure, and improves retinal ganglion cells function in glaucoma. J Pineal Res. May;70(4):e12730. ↩
  4. Stefanova NA, ZHdankina AA, Fursova AZ, Kolosova NG. (2013). Potential of melatonin for prevention of age-related macular degeneration: experimental study. Adv Gerontol. 26(1):122-9. ↩
  5. Yi C, Pan X, Yan H, Guo M, Pierpaoli W. (2005). Effects of melatonin in age-related macular degeneration. Ann N Y Acad Sci. Dec;1057:384-92. ↩
  6. Mehrzadi S, Hemati K, Reiter RJ, Hosseinzadeh A. (2020). Mitochondrial dysfunction in age-related macular degeneration: melatonin as a potential treatment. Ther Targets. Apr;24(4):359-378. ↩
  7. Blasiak J, Reiter RJ, Kaarniranta K. (2016). Melatonin in Retinal Physiology and Pathology: The Case of Age-Related Macular Degeneration. Oxid Med Cell Longev. 2016:6819736. ↩
  8. Pack W, Hill DD, Wong KY. (2015). Melatonin modulates M4-type ganglion-cell photoreceptors. Neuroscience. Sep 10;303:178-88. ↩
  9. Cao D, Nicandro N, Barrionuevo PA. (2015). A five-primary photostimulator suitable for studying intrinsically photosensitive retinal ganglion cell functions in humans. J Vis. Jan 26;15(1):15.1.27. ↩
  10. Khorsand M, Akmali M, Sharzad S, Beheshtitabar (2016). Melatonin Reduces Cataract Formation and Aldose Reductase Activity in Lenses of Streptozotocin-induced Diabetic Rat. Iran J Med Sci. Jul;41(4):305-13. ↩
  11. Abe M, Reiter RJ, Orhii PB, Hara M, Poegeler B. (1994). Inhibitory effect of melatonin on cataract formation in newborn rats: evidence for an antioxidative role for melatonin. J Pineal Res, Sep;17(2):94-100. ↩
  12. Rosenstein RE, Pandi-Perumal SR, Srinivasan V, Spence DW, Brown GM, et al. (2010). Melatonin as a therapeutic tool in ophthalmology: implications for glaucoma and uveitis. J Pineal Res. Aug;49(1):1-13. ↩
  13. Scuderi L, Davinelli S, Iodice CM, Bartollino S, Scapagnini G, et al. (2019). Melatonin: Implications for Ocular Disease and Therapeutic Potential.
    Curr Pharm Des. 2019;25(39):4185-4191. ↩
  14. Aranda ML, Fleitas MFG, Dieguez H, Iaquinandi A, Sande PH, Dorfman D, et al. (2017). Melatonin as a Therapeutic Resource for Inflammatory Visual Diseases. Curr Neuropharmacol. 2017;15(7):951-962. ↩
  15. Chih-Chao Chang CC, Tien-Yi Huang TY, Hsin-Yuan Chen HY, Tsui-Chin Huang TC, Lin LC, et al. (2018). Protective Effect of Melatonin against Oxidative Stress-Induced Apoptosis and Enhanced Autophagy in Human Retinal Pigment Epithelium Cells. Oxid Med Cell Longev. Aug 5;2018:9015765. ↩