A popular supplement most often used to help you get shut-eye may actually help you preserve your eyes, with new research linking melatonin and age-related macular degeneration (AMD).
Researchers at Case Western Reserve University School of Medicine assessed records of more than 200,000 people who either had no history of age-related eyesight decline or had developed the slow-progressing nonexudative AMD. Of the 121,523 patients who were aged 50 or older with no history of AMD, regular melatonin use was linked to a 58% reduction in risk of developing the condition. In the 66,253 patients with early eyesight degeneration, melatonin use presented a 56% lower risk in this condition progressing.
These results, which assessed medical records from 2008 to 2023, were consistent when patients were further divided into age groups of around 60, 70 and 80 years.
As the name suggests, AMD affects the macula, which is found at the back of the eye and is the central part of the retina that processes what you see directly in front of you. Some 11 million Americans are affected by this condition, and its progression is one of the main culprits in age-related blindness.
In a 2020 study on mice, researchers showed for the first time that melatonin helped protect the retina from damage and the progression of nonexudative AMD. Then a study in 2021 found that patients with AMD had lower melatonin levels in blood serum and tear fluid, while another paper released the same year demonstrated that supplementary melatonin mitigated the progression of the retinal neurodegenerative disease retinitis pigmentosa. However, research is still very much in its early days.
Melatonin is a hormone naturally produced in the brain, particularly at the onset of darkness, which helps regulate our sleep-wake cycles. Melatonin supplements were approved by the FDA in 2005 and are a common sight on pharmacy shelves in the US. Most often it's seen as a 'natural' treatment for insomnia and other sleep disorders, including jet lag.
This latest study adds more weight to the growing evidence of melatonin's positive impact on age-related eyesight degeneration, however, researchers point out their work nonetheless has its limitations. There are many lifestyle factors associated with both nonexudative and exudative AMD, including diet and cigarette smoking. In addition to this, those taking supplements may overall be more proactive in maintaining their health, which would then reduce their lifestyle risks of age-related eyesight loss.
And despite extensive data, it was unknown how often participants took melatonin, or what dosage. The researchers say more work needs to be done in testing, controlling for these variables, but their study makes a strong case for further investigation.
The study was published in JAMA Opthalmology
Source: Case Western Reserve University via Scimex