Carrots aren’t the only orange-coloured food that is beneficial for eye health.
A recent study by the Queensland Alliance for Agricultural and Food Innovation has found that orange capsicums contain the richest source of the orange pigment zeaxanthin, which is vital for central vision used to read, drive and see pictures and faces.
This is different to the eye-benefitting orange pigment in carrots, called beta-carotene, which benefits night vision.
Associate professor Tim O’Hare, who conducted the study, says zeaxanthin accumulates in the macula, at the back of the eyes.
It protects against blue light, which damages the light receptors in the retina responsible for high-resolution central vision and colour perception. Sources of blue light include digital screens, the sun, digital and fluorescent LED lighting.
The more zeaxanthin in your macula, the more blue light is naturally screened from hitting the back of the eye, says Tim.
It’s in the colour
Zeaxanthin deficiency leaves eyes susceptible to age-related macular degeneration. Tim stresses that food is essential to achieve this protection.
“Our bodies can’t make zeaxanthin, which means we rely exclusively on dietary sources or on artificial supplements.”
While zeaxanthin can be found in other foods such as paprika, corn and saffron, Tim says the levels tend to be quite low.
The study found that one orange capsicum, which is typically 450g, contains zeaxanthin levels equivalent to 30 supplement tablets, with 2mg of zeaxanthin the daily recommended dose.
“Each zeaxanthin tablet is roughly equivalent to 10g of orange capsicum flesh – that’s how rich the capsicums are in this pigment,” says Tim.
“A number of nutrients we are interested in for human health are actually pigmented. In most cases, it’s the zeaxanthin itself that gives orange capsicums their vivid orange colour.
“With these nutrients, what you see is what you get – the more intensely coloured the product, the more nutrient they contain.”
An unpopular capsicum
In contrast, the less ripe green and yellow capsicums, and the ripest red capsicum, contain no zeaxanthin.
Countdown New Zealand say orange capsicums make up less than 10 per cent of capsicum sales throughout their New Zealand supermarkets.
“In our stores red capsicums make up more than half our capsicum sales,” says a Countdown New Zealand spokesperson.
“In our experience Kiwis are really interested in looking after their health so we’d expect that many customers will look at this particular study with interest.”