If you want patients to fend off age-related cataracts, the answer may be as simple as adding antioxidant-rich fruits and vegetables to their diet.

Researchers from China and the University of South Australia found certain vitamins and carotenoids were associated with a significantly decreased risk of age-related cataracts. The international study also claimed the $5.7 billion global tab to restore sight for the estimated 45 million people with cataracts could be slashed in half by a diet that includes colorful fruits and vegetables.

 The investigators analyzed 20 studies from around the globe that investigated the impact of vitamins and carotenoids on cataract risk. Despite some inconsistencies, the findings significantly touted the benefits of eating citrus fruits, capsicum, carrots, tomatoes and dark green vegetables such as spinach, broccoli and kale to delay the onset of age-related cataracts.

Researchers included eight randomized controlled trials and 12 cohort studies in their analysis.

In the cohort studies, higher consumption of certain vitamins and carotenoids including vitamin A, vitamin C, vitamin E, β-carotene and lutein or zeaxanthin was associated with a significant decreased risk of age-related cataracts. Additionally, investigators reported higher doses of the vitamins and carotenoids cut the risk of age-related cataract significantly. This included a 26% decrease for every 10mg/d increase of lutein or zeaxanthin; a decreased risk of 18% for each 500mg/d increase of vitamin C; an 8% decreased risk for each 5mg/d increase of β-carotene; and a 6% decreased risk for every 5mg/d increase in vitamin A.

However, evidence from the randomized controlled trials was less clear, the investigators reported. In the randomized controlled trials, neither vitamin E nor β-carotene intervention reduced the risk of age-related cataracts significantly compared with the placebo group.

Since the population is aging dramatically, coupled with the increasing number of people needing surgery, urgent action is needed, the researchers said in their paper. By delaying the onset of age-related cataracts by a decade, the number of patients requiring surgery could be cut by half, they speculated.

Still, challenges remain, as the current consumption of antioxidants falls short of the recommended level to prevent-age related cataracts, they added.