Dietary vitamins may protect against cataract
When the lens of the eye becomes cloudy, it’s known as a cataract.
Cataracts are more common as people age and symptoms include blurry vision, light sensitivity and the yellowing of colours (they may also become less vibrant).
Globally, cataract is the leading cause of vision impairment and in Australia, more than 700,000 people are affected by cataracts. An operation to remove the cataract isn’t especially complex, but it does involve an anaesthetic, the risk of complications, a recovery period and costs, so reducing the cataract burden in Australia would be useful.
Protecting your eyes from the sun and not smoking both reduce your risk, but what about nutrition? Is your mother’s urging to eat your carrots so you don’t go blind really true?
This research looked at studies where groups of people had been prescribed daily vitamins and a carotenoid in their diet rather than supplements.
Carotenoids are organic pigments that give certain vegetables their colour – like carrots, corn and bananas.
Higher intakes of these pigments have previously been associated with healthier eyes. The studies then looked to see whether the group who took in more daily vitamins and carotenoids developed less age-related cataracts over time (compared with the group who didn’t have the vitamins).
They found that increasing one’s intake of vitamins and carotenoids in the diet reduced the risk of age-related cataracts. It was tricky to unpick the interactions of different vitamins but the overall evidence suggested that citrus fruits, capsicum, carrots, tomatoes and dark green vegetables all had benefits.
The researchers also looked at people who took vitamin E and beta-carotene supplements, but didn’t find any effect on someone’s risk of developing cataracts.
The authors say that this has significant public health ramifications. If everybody increased their dietary intake of vitamins and carotenoids, there would be a significant reduction in cataracts and a big saving to the health system in the form of reduced need for cataract operations (one of the most popular elective surgeries in Australia).
But they also note that achieving this dietary change is difficult. Most of the Western world doesn’t eat the recommended amounts of fruit and veggies recommended for good eye health.
Last Reviewed: 03/03/2020
© Norman Swan Medical Communications.
For reference: Jiang, et al (2019). Dietary vitamin and carotenoid intake and risk of age-related cataract. American Journal of Clinical Nutrition doi: 10.1093/ajcn/nqy270.