Antioxidant power: Colorful produce consumption linked to lower risk of cataracts

26 Mar 2019 --- Consuming foods that are high in antioxidants – such as colorful fruit and vegetables – may lower the risk of age-related cataracts (ARC) and cut restorative eye-sight medical bills by half. This is according to an international study from the University of South Australia (UniSA) in collaboration with researchers from China. The findings also showed that the regular intake of colorful produce may delay the onset of cataracts by a decade. The authors highlight the importance of raising the consumption of antioxidant-rich foods for better eye health.

The study appeared in the American Journal of Clinical Nutrition, in light of World Optometry Week (March 26-30).

An estimated 45 million people suffer from cataracts globally and the cost of medical care they require reaches up to US$5.7 billion. These number could be reduced by 50 percent by the regular consumption of antioxidant-rich foods, says Dr. Ming Li, Senior Research Fellow at UniSA. Dr. Li and her colleagues from Xi’an Jiaotong University, China analyzed 20 studies from around the world to examine the impact of vitamins and carotenoids on cataract risk.

“Age-related cataracts is the leading cause of visual impairment among the elderly throughout the world, with unoperated cataracts contributing to 35 percent of all blindness,” Dr. Li says. “Although cataract extraction surgery is an effective method to restore vision, it will have cost society more than US$5.7 billion by 2020.”

Despite some inconsistencies, the findings overwhelmingly support the benefits of eating citrus fruits, capsicum, carrots, tomatoes and dark green vegetables such as spinach, broccoli and kale to delay the onset of ARC.

The researchers support that as the global population is aging dramatically and an increasing number of people need surgery, urgent action is needed.

“If we could delay the onset of ARC by 10 years it could reduce by half the number of people requiring surgery,” the report finds. However, the authors note that current consumption of antioxidants is well below the recommended level to prevent age-related cataracts and global improvement in dietary habits is required. 

Combating age-related eyesight impairment is an increasing concern among the aging population. Last year, a review of 18 studies on the role of diet and food intake on age-related macular degeneration (AMD) found that the Western diet had an increased association with the disease. AMD is the leading cause of vision loss in adults aged over 50 and diet has long been noted as a risk and protective factor.

In the same space, researchers from the US National Eye Institute (NEI) found that consuming a calcium-rich diet or taking calcium supplements does not appear to increase the risk of age-related macular degeneration (AMD). The findings contradict an earlier study which put forward that high levels of calcium were linked to an increased prevalence of vision disorder. They are consistent with another study suggesting that calcium has a protective role in AMD, however.

Fatty acids have been touted as supporting eye health but a study funded by the National Eye Institute (NEI) found that omega 3 fatty acid supplements yield no more beneficial results for dry eye symptoms than a placebo – in this case, olive oil. “The trial provides the most reliable and generalizable evidence thus far on omega 3 supplementation for dry eye disease,” says Maryann Redford, D.D.S., M.P.H., program officer for clinical research at NEI.