Our eyes are under a lot of strain and sadly, for some of us, this will lead to serious damage and even blindness later in life. The culprit? Blue light emitted from our personal digital devices, computers and lighting. Over time, these harmful rays can cause degeneration of our retinas and lead to sight loss.
But it’s not all doom and gloom. Scientists at Harvard University have shown that certain superfoods actually protect against the damaging effects of blue light and can protect our eyesight in the future.
What’s the science?
The reason blue light is so dangerous is that is has a much higher frequency than other visible light. This means the light rays vibrate more violently as they enter your eye, causing damage to your retina. Specifically, they damage your macula – a highly-pigmented area at the back of the retina.
The macula acts as a filter to blue light. It’s packed with yellow pigment, which fends of those harmful rays. Repeatedly having to do this takes its toll however, leading to what is called advanced macular degeneration. This condition is the leading cause of blindness in the West, affecting a staggering 30% of people over the age of 75. And we can only assume that, in the age of the ever-present smartphone, this figure looks set to rise.
How can superfoods help?
The Harvard study found that the nutrients in certain superfoods have a significant benefit to the health of our eyes. It followed the visual health of over 100,000 participants over the course of 20 years to conclude that two nutrients are vital in protecting against macular degeneration: lutein and zeaxanthin.
Researchers showed that people eating a diet rich in lutein and zeaxanthin are 40% less likely to suffer from advanced age-related macular degeneration. The reason? These two little carotenoids contain the yellow pigment the macula needs to be able to filter out blue light. Pretty clever huh?
Which superfoods should I be eating?
Top of the list is superfood favorite, kale. We always knew we loved these nutrient-dense greens and it can feature in a wide range of dishes from stir-fry to smoothies. If you’re not keen on its earthy taste don’t worry, there are also clever products and supplements that make eating your greens so much easier. Try Perfect Fermented Kale to quickly and easily get concentrated kale into your diet.
Other foods high in lutein and zeaxanthin include raw cress, raw spinach, cooked spinach and green peas. And in a slightly disappointing myth-buster, carrots were found to have relatively low levels of eyesight-protecting nutrients.
So, it looks like eating your greens is a must when it comes to protecting your eyesight. But exactly how many greens do you need to eat?
How much lutein and zeaxanthin do I need?
At this point in time, there is no established Recommended Dietary Allowance (RDA) for either lutein or zeaxanthin. However, in another study into visual health – the Age-Related Eye Disease Study (AREDS2) – just 10mg of lutein and 2mg of zeaxanthin per day were found to have significant benefits to macular health.
In the study, this was provided in the form of a supplement but just one cup (or 100g) of cooked kale is thought to contain around 20mg of lutein and zeaxanthin. Five portions a day of other green vegetables, such as spinach, broccoli and peas, would also provide you with sufficient levels of these very special carotenoids. That’s a pretty delicious way to protect your eyesight!
Image Credit: Focus Clinics