By Xin Chang
Have your parents ever told you to eat vegetables to improve your eyesight? Have you been told that the color green improves your vision? You might think this is the reason why you are forced to eat the combination of the two, green vegetables, but this common misconception is actually only partly true. In fact, the color green only has psychological effects on eyes, rather than physical, which has been proven time after time by psychologists.
Green leafy vegetables, like kale and spinach, are made of chlorophyll, which gives them a rich green color. These veggies, however, are most importantly rich in lutein and zeaxanthin, which helps slow down macular degeneration, the cause of blurry vision as you become older. Of course, lutein and zeaxanthin are not limited to only green vegetables. Orange and yellow colored fruits and vegetables are also found to be rich in these nutrients. According a 1998 study, orange peppers had the highest amount of zeaxanthin of the 33 fruits and vegetables tested, higher than all the green veggies! The author found that the green leafy vegetables generally has a higher content of lutein (about 15 to 47 percent), but they have a very low content of zeaxanthin.(about 0 to 3 percent). The study also shows that fruits and vegetables of all colors can be consumed to increase dietary intake of lutein and zeaxanthin.
Besides dark green leafy vegetables and colorful fruit and vegetables, egg yolk is another great source of both lutein and zeaxanthin, along with an intake of healthy fat and protein. They are nearly an ideal form of highly absorbable carotenoides even though they consist of lower levels than many vegetables. According to a study published in 2015, adding one or two eggs to your daily salad can also increase the carotenoid absorption as much as nine-fold from the whole meal without the yellow mushy spheres. The free-range, pastured hens will produce bright orange yolks from their eggs, which is an indication of their elevated lutein and zeaxanthin contents. But those dull and pale yellow yolks are a definite sign of low amounts of the valuable nutrients. They usually come from eggs from caged hens who were fed an unnatural grain diet. Healthy fats are also important ingredients in order to better absorb these nutrients, so organic salt free butter, coconut or olive oil are all good choice to add into your food. The next time you are told to eat more greens, be sure to remind them that all the colors of the rainbow are essential to your health.