Everyone knows that carrots are good for your eyesight. But why is that? And are there any other foods we should recommend to our patients for promoting eye health? Here are five popular foods claimed to improve eye health.
Carrots contain lutein and beta-carotene, a substance converted to vitamin A by the body. Vitamin A is an essential nutrient for cell growth and ocular development. A lack of vitamin A leads to night-blindness, retinal scarring and blindness. Worldwide, an estimated 250,000 t0 500,000 children become blind every year due to vitamin A deficiency and half of them die within 12 months of losing their sight.
Beta-carotene was part of the original AREDS (age related eye disease study) formula but the AREDS2 study found that Lutein and Zeaxanthin have a bigger role to play in AMD (Age-related macular degeneration) management and should replace beta-carotene in future formulae. High levels of beta-carotene taken as a supplement were shown to double the risk of lung cancer in smokers.
Our Verdict: A lack of carrots is bad for your eyesight.
Egg yolks contain high levels of lutein and zeaxanthin. Both these yellow pigmented antioxidants belong to a class of compounds called carotenoids. Leutein and zeaxanthin selectively accumulate in the macular of the retina, scavenging free radicals and acting as a blue light filter. Low plasma levels of lutein and zeaxanthin are associated with the increased risk of AMD.
Some experts suggest that we need about 6mg of these antioxidants a day. One egg yolk has about 0.25mg of lutein, more than most fruits. The body absorbs lutein found in egg yolks more easily, than it does that are found in fruits or vegetables.
Our Verdict: Egg yolks have surprisingly high levels of bio-available lutein and zeaxanthin.
Spinach, like many green, leafy vegetables contain lots of lutein (7mg per serving) but little or no zeaxanthin. Consuming it raw and whole is best, chopping and heating spinach is known to damage some of its antioxidants. While the levels of lutein are significantly higher than in egg yolks, the bioavailability is thought to be lower.
Kale, broccoli, romaine lettuce, peas, brussels sprouts, courgette and other greens also contain high amounts of lutein.
Our verdict: Leafy green vegetables are a must for ocular health and for a balanced diet.
Blueberries, also referred to as “brainberries,” are considered by some to be the healthiest food on the planet. They contain high concentrations of vitamins, A,C,E and Zinc, the ingredients in the original AREDS formula.
In theory, antioxidants should protect the retina and other tissues such as the lens against photochemical damage from sunlight, but there is little or no scientific research linking blueberries to improvements or maintenance of ocular health.
Our verdict: We love blueberries but the science behind their ocular benefits is poor.
Almonds are rich in vitamin E. They also contain amygdalin (Vitamin B17) which some people claim is an anti-cancer nutrient. There is no scientific evidence to support claims that amygdalin can treat cancer or any other illness.
Other nuts such as flax seeds, chia seeds and walnuts are high in omega-3 fatty-acids. Diets rich in omega-3 have been shown to manage dry eye symptoms and may help protect against AMD.
Our verdict: you’re better off eating walnuts or oily fish.