吃胡蘿蔔真的可以幫助保護視力嗎？保護和提高視力的秘密到底是什麼？吃保健品或多吃某些食物能有幫助嗎？研究顯示人們可以通過食用含有葉黃素的膳食補充劑來提高視力。葉黃素可以保護視網膜免受有害光線的損傷。本期《隨身英語》介紹對人眼和視力有益的食物。
Do carrots really help you see in the dark? What about kiwis or kale? Can eating certain foods improve your eyesight or prevent your eyes degenerating? Perhaps we should all be taking supplements to benefit our vision? Research in both the US and Ireland has shown that supplementing the diet with certain key chemicals can significantly benefit your vision. These can be taken as supplements but they are also found widely in many green leafy plants and green and yellow fruit and vegetables.
The retina is the part of our eye that contains cells sensitive to light. The most delicate area of this tissue – the macula – is protected from harmful blue and UV light by yellowish 『macular pigment』. This acts like sunglasses, blocking the damaging light. It comprises three pigments – lutein, zeaxanthin and meso-zeaxanthin.
A research team led by Professor Nolan in Ireland has recently completed a year-long trial investigating the benefits of taking supplements of macular pigments. 100 participants took part in the experiments. The results showed that by taking lutein, zeaxanthin and meso-zeaxanthin, there was a significant improvement in the protection of the macula, as well as in overall eyesight. There was also some evidence that these chemicals can help to slow down macular degeneration, which is the main cause of sight loss in the UK. However, this is somewhat controversial.
Lutein is a yellow compound found only in plants, which produce it to absorb light. We can get lutein by eating foods like kale and spinach. It is also present in egg yolk. Zeaxanthin, another yellow compound similar to lutein, is found in such foods as corn, yellow bell peppers and saffron. Meso-zeaxanthin is not generally found in food sources, though it can be found in some fish. It is created in the retina from ingested lutein. It can be taken in supplements made with marigold extracts.
As for carrots, it turns out that it’s the leafy green bits on the top that contain the key compounds beneficial to eyesight, rather than the vegetable itself. So next time you’re told carrots help you see in the dark, save them for the rabbit and chop up some kiwi instead!
詞彙表kale （蔬菜）羽衣甘藍
to degenerate 下降，衰退
supplement 補充物，補充片劑
chemical 化學品
vision 視力
retina 視網膜
tissue 組織
macula 視網膜黃斑
pigment 色素
lutein 葉黃素
zeaxanthin 玉米黃素
meso-zeaxanthin 消旋玉米黃素
sight loss 失明
compound 化合物
saffron 藏紅花
to ingest 攝取
marigold extract 萬壽菊提取物