Can Melatonin Help Prevent Age-Related Macular Degeneration?

September 1, 2024

by Cathe Friedrich

Can you imagine how it would feel to pick up your favorite book to read and find that the text is blurred? If you’re older, you might think cataracts are the reason your vision is off, but there’s another common age-related eye condition. It’s age-related macular degeneration (AMD).

Age-related macular degeneration (AMD) is an eye condition that challenges the vision of millions of people worldwide. It’s also the most common cause of visual loss in people over the age of 50. Could a common supplement slow down its progression?

What Is AMD?

Age-related macular degeneration is a disease that affects the life-sensitive structure called the retina. When light hits the back of your eye, it strikes your retina. In turn, the retina converts the light you see into electrical signals your brain can interpret. AMD mainly affects the central portion of the retina, called the macula. As we age, the macula can deteriorate, leading to blurred or distorted vision. Damage to the retain from exposure to sunlight also plays a role, as does genetics.

AMD comes in two types:

Dry AMD: This type of AMD involves gradual thinning of the macula, and the growth of yellow deposits called drusen. It’s the most common kind, making up around 80% of cases.

Wet AMD: This is a more severe form of the disease. With this type, abnormal blood vessels grow beneath the retina that leak fluid. People with this form of AMD can experience rapid visual loss.

When you have AMD, you may notice that the things you see in the center of your vision look blurred. For example, you might have trouble reading a book because you can’t make out the letters. With AMD, your peripheral vision may still be acceptable. You may also have trouble driving a car, as the disease progresses.

AMD Isn’t Curable

Scientists have yet to find a cure for AMD, although lifestyle changes may slow down its progression. Ophthalmologists may prescribe antioxidant supplements to slow down the process. But recently, scientists have discovered another supplement that could prevent or slow the progress of AMD. It’s melatonin, a hormone that the pineal gland in your brain produces.

Melatonin helps regulate your internal biological clock and circadian rhythms, the time schedule your body uses to decide when to release hormones and other molecules that affect your health. Some people take supplemental melatonin to relieve jet lag and to help them fall asleep at night. Could melatonin also be beneficial for AMD?

The Science Behind Melatonin and AMD

Researchers at Case Western Reserve University and the Cole Eye Institute recently looked at data from more than 200,000 people, some of whom had AMD and who took melatonin supplements. Their findings? They discovered a correlation between taking melatonin supplements and a lower risk of developing AMD.

While this is a correlational study that can’t show that melatonin prevents or slows the progression of AMD, there are reasons why melatonin could be an effective preventative or could slow AMD’s progression. Along with being a regulator of the circadian rhythms and the sleep-wake cycle, melatonin is a powerful antioxidant. Researchers say it may stave off oxidative stress that contributes to damage to the retina. So, it could help prevent AMD and be a helpful adjunct to other treatments.

Considerations and Cautions

Although melatonin holds promise for AMD, it’s too early to say it’s a safe and effective treatment. Even if it works, melatonin supplements aren’t regulated in the same way medications are. The melatonin supplements you buy at vitamin stores and online may have varying levels of melatonin and may contain more or less than what the label says. Plus, melatonin can interact with some medications.

That’s why it’s important to talk to your healthcare provider before taking it to prevent or treat AMD. It’s unclear what the ideal dosage would be too. Most people take 0.3 to 3 milligrams at night for sleep and for jet lag, but it’s not clear whether that’s the best dosage for AMD.

Could Melatonin Be a Complementary Therapy for AMD?

With limited treatment options for AMD, melatonin could be a safe alternative, but it needs more research. Although there’s no cure, certain other antioxidants, based on some studies, can slow its progression. These include:

Vitamin C: Helps protect the macula against deterioration and loss of vision.
Vitamin E: Acts as an antioxidant to prevent cellular damage in the retina.
Beta-carotene: Originally used in the AREDS formula, but its use has been reconsidered due to the increased risk of lung cancer in smokers.
Lutein and Zeaxanthin: These carotenoids may be effective in reducing the risk of AMD progression.
Zinc: Essential for eye health and included in the AREDS and AREDS2 supplement formulas.

Some ophthalmologists prescribe a supplement, called AREDS2, that contains the above vitamins and antioxidants for people who have AMD. The hope is to slow its progress. Melatonin could be an addition to this list of free-radical quenching antioxidants if further research supports its benefits.

Conclusion: A Promising Path Forward

While we need more research, the antioxidant power of melatonin shows promise for the vision-robbing disease, AMD. If confirmed, melatonin could offer a simple, accessible way to safeguard our eyesight and enjoy a better quality of life as we age. It’s a future worth looking forward to.

References:

Jeong H, Shaia JK, Markle JC, Talcott KE, Singh RP. Melatonin and Risk of Age-Related Macular Degeneration. JAMA Ophthalmol. 2024 Jul 1;142(7):648-654. doi: 10.1001/jamaophthalmol.2024.1822. PMID: 38842832; PMCID: PMC11157446.
Vyawahare H, Shinde P. Age-Related Macular Degeneration: Epidemiology, Pathophysiology, Diagnosis, and Treatment. Cureus. 2022 Sep 26;14(9):e29583. doi: 10.7759/cureus.29583. PMID: 36312607; PMCID: PMC9595233.
Friedman DS, O’Colmain BJ, Muñoz B, Tomany SC, McCarty C, de Jong PT, Nemesure B, Mitchell P, Kempen J; Eye Diseases Prevalence Research Group. Prevalence of age-related macular degeneration in the United States. Arch Ophthalmol. 2004 Apr;122(4):564-72. doi: 10.1001/archopht.122.4.564. Erratum in: Arch Ophthalmol. 2011 Sep;129(9):1188. PMID: 15078675.
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