World War II, the British Air Force rely on night combat aircraft shot down by the Germans do? In accordance with the earlier statement of the British Ministry of Food, pilots rely on the holy grail is to eat carrots! With this publicity, the authorities called on citizens to eat more locally produced vegetables, especially rich in -carotene root vegetables. Of course, a few years later, it is known RAF real secret weapon is radar technology, "said Carrot," it is only the intelligence impaired eye trick Bale.
So, what carrots can really promote the vision, it is groundless?
The answer is yes, under certain circumstances, eating carrots really help vision. The body can make use of -carotene synthesis of vitamin A, vitamin A helps the eyes will be transformed into a light signal transmission to the brain, so that people could see in the dark object. In addition, if the body does not get enough vitamin A can also affect the cornea, the world there are about 25-50 million children each year because of vitamin A deficiency and blindness. Vitamin A deficiency in malnourished populations like Nepal and India appear in -carotene and vitamin supplements can promote people's night vision.
However, the next question is: in the end how much to eat carrots in order to promote the vision of it? At present, most research is for -carotene and vitamin A supplements, rather than the carrot. One conducted in 2005 for randomized controlled trials of pregnant women, a group of six days a week to eat 4-5 ounces (110-140 grams) of cooked carrots crowd with the use of other methods of vitamin A supplementation (fortified rice, spinach and goat liver, etc. ) people in improving the approximate effect of night blindness, including vitamin a supplements best. The study also found that the conventional diet for 6 weeks the amount of food cooked carrots can make their night vision returned to normal.
However, some studies have shown that -carotene can not effectively be converted to vitamin A, dietary 12-21 parts of -carotene can be converted to 1 part of vitamin A. So, if possible, it is recommended to take vitamin A supplements directly, rather than carrots.
"There is no doubt that vitamin A is very important", Emily Chew, deputy director of the National Eye Institute of Clinical stressed, "but also did not eat binge eating carrots to improve vision, once the body intake enough -carotene, it will not then into vitamin a, and human machine experience naturally regulate excess vitamin a to prevent the accumulation of toxic, but how many carrots to eat better? I totally can not give a specific amount. "However, she also pointed out that a balanced diet of the most important, if you eat a lot of carrots can cause yellowing of the skin, of course, this symptom is no health hazard. In addition, many vision problems due to heredity, aging and diabetes caused by the intake of -carotene and will not be improved.
First night blindness are described in the ancient Egyptian text, then the treatment is very simple, grilled goat will squeeze juice directly onto the eyes of the patients. However, the well-known ophthalmologist Alfred Sommer later questioned if the patient in the treatment of recovery after such a vision, it is possible to eat the rest of the goat.
Chew suggested that people want to improve vision through food, is important to eat a variety of leafy vegetables such as spinach, kale and cabbage and other rich in rutin and zeaxanthin vegetables, they can help our eyes may filter out retinal damage energetic wavelengths of visible light, but also to prevent common in the elderly due to macular degeneration, blindness disease.
(Author: Zhao via Scientific American)
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