A cohort study by American scientists has shown that curcumin supplements reduce the risk of age-related macular degeneration, which affects vision in older people. As reported in JAMA Ophthalmology, people taking curcumin had a reduced risk of developing various forms of macular degeneration, as well as the risk of developing blindness. However, the study does not provide information on the dose and regimen for taking such supplements.
Age-related macular degeneration (AMD) is a disease in which oxidative damage and chronic inflammation occur in the retina, destroying photosensitive cells and leading to blindness. Genetic predisposition plays an important role in the development of the disease. The main approaches to treating this disease are the introduction of a vascular endothelial growth factor inhibitor and, potentially, complement inhibitors.
Turmeric, extracted from the rhizomes of the plant Curcuma longa, is used as a seasoning for dishes. However, it is also used as a traditional medicine in various regions of Asia. It is assumed that the pharmacological activity of curcumin, which is part of the turmeric root, lies in the antioxidant and anti-inflammatory effect due to the suppression of the production of free radicals and a number of inflammation markers. However, the relationship between curcumin consumption and the development and progression of AMD has been studied only in vitro and animal studies.
A research team led by Ehsan Rahimy of Stanford University School of Medicine conducted a retrospective cohort study using the Trinity Health Research Network, which aggregates electronic health record data from more than 107 health care organizations in 15 countries. A total of 66,804 patients (mean age 64.9 years; 44,124 women, 22,406 men) without AMD took curcumin supplements, and a matched control group of 1,809,440 people did not take curcumin.
A quasi-randomized analysis showed that among patients aged 50 years and older, curcumin supplementation reduced the risk of developing both dry (non-exudative) AMD (relative risk (RR) 0.23; p < 0.001) and exudative AMD (RR 0.28; p < 0.001). Curcumin supplementation also reduced the risk of developing complete blindness (RR 0.46; p < 0.001). The mean follow-up time was more than 1,500 days (more than four years) in both groups. A similar pattern was observed in patients aged 60 and 70 years and older. Curcumin supplementation also reduced the likelihood of subsequent vascular endothelial growth factor inhibitor procedures in all age groups. The authors cite the inability to standardize data on the duration, dose, frequency of administration, and bioavailability of turmeric supplements as one of the main limitations of this study. The sample included patients with information only about the prescription of such supplements. Therefore, further clinical studies with clearer inclusion and intervention criteria are needed. We have previously reported that melatonin intake reduces the risk of age-related macular degeneration and its progression.