You know eating fruit and vegetables is virtuous. But did you know it can also make you look good?

　　People who increased their intake over just six weeks developed a healthy glow and appeared more attractive, researchers found。

　　Scientists at St Andrews University found eating them subtly increased yellow and red pigments in the volunteers’ skin。

　　They monitored the food intake of 35 people and took pictures of their faces, arms and hands using a sensitive camera at the start, and after three and six weeks。

　　Increasing their intake of greens by 2.9 portions a day was found to make the person look more healthy and an extra 3.3 portions could enhance their attractiveness, when their photographs were rated by others。

　　Fruit and vegetables are rich in carotenoids, which are known to protect against cell damage from pollution and UV rays, and can also prevent age-related diseases including heart disease and cancer。

　　But while it was known eating extreme amounts of certain vegetables such as carrots could turn skin orange, it was not known a small increase was perceptible to others - and was seen as appealing。

　　A camera measured changes to the skin’s redness, yellowness and lightness, and found it significantly changed in people who naturally increased their intake. These changes were not evident at three weeks。

　　Using light sensors, the researchers showed these red and yellow hues were linked with the levels of carotenoids in their skin。

　　There are hundreds of carotenoids but those thought to have the most dramatic effect are lycopene - which gives tomatoes and red peppers their red colour - and beta-carotene found in carrots as well as broccoli, squash, and spinach。

　　Skin colour is also affected by chemicals called polyphenols, found in apples, blueberries and cherries, which cause blood rush to the skin surface。

　　你知道吃水果和蔬菜有很多好处，但你可知道多吃水果蔬菜会让你变漂亮?

　　研究人员发现，增大水果蔬菜的摄入量，只需六周就能让你焕发出健康的光彩，看起来更有魅力。

　　圣安德鲁斯大学的科学家发现，吃水果蔬菜能微量增加志愿者皮肤中的黄色素和红色素。

　　他们监测了35人的食物摄入量，并在一开始、三周后和六周后用高灵敏相机给他们的脸、胳膊和手拍了照片。

　　研究发现，从他人对照片的打分来看，每日增加2.9份的蔬菜摄入量将让人看起来更健康，再增加3.3份摄入量将使人看起来更有魅力。

　　水果和蔬菜的类胡萝卜素很丰富，而据我们所知，类胡萝卜素可以保护细胞不受污染和紫外线的损害，还可以防止心脏病和癌症等老年病。

　　不过，尽管人们知道某些蔬菜(如胡萝卜)摄入过量会让皮肤变成橘黄色，但人们不知道这种细微变化会被他人觉察到，而且这种皮肤颜色还被视为很有吸引力。

　　研究人员通过相机拍照来测量皮肤的红色、黄色和明亮度发生的变化，发现那些以自然的方式增加蔬菜水果摄入量的人的皮肤发生了明显改变。不过这些改变在三周内还看不出来。

　　借助光传感器，研究人员指出，皮肤呈现的红色和黄色与皮肤内所含的类胡萝卜素水平有关。

　　类胡萝卜素有数百种，但据认为对皮肤颜色影响最显著的是番茄红素和胡萝卜素。西红柿和红辣椒的红色都源自番茄红素，胡萝卜素则可以在花椰菜、南瓜、菠菜和胡萝卜中找到。

　　皮肤颜色还受到化学物质多元酚的影响，多元酚可以在苹果、蓝莓和樱桃中找到，这种物质可以让血液流向皮肤表面。