Eating your five-a-day 每天至少要吃五份果蔬

　　不少人提倡多吃水果和蔬菜。事实证明，吃果蔬确实有助于改善健康。专家建议每天应吃 “five-a-day（五份水果和蔬菜）”。但在日常生活中，坚持这种饮食方式容易吗？我们是否应设定一个更现实的饮食目标来保持健康？本期节目探讨英文谚语 “An apple a day keeps the doctor away. （每天一苹果，医生远离我。）” 背后的科学依据。

　　词汇：health 健康

　　We all know about the benefits of a healthy diet. 'We are what we eat', so some say. But sometimes our busy lives mean our healthy intentions slip, and we end up eating the wrong things. Messaging telling us to eat our 'five-a-day' encourages us to maintain a balanced diet – but is it accurate?

　　If you're not sure what your 'five-a-day' is, it's a campaign based on advice from the World Health Organization which recommends eating a minimum of 400g of fruit and vegetables a day. That should lower the risk of serious health problems, such as heart disease, stroke and some types of cancer. Variety is important because different fruits and vegetables contain different combinations of fibre, vitamins, minerals and other nutrients¹.

　　Eating five pieces of fruit and veg is something to aim for. An analysis of 16 worldwide studies suggested that for every portion of fruit and vegetables consumed, there was a lower risk of premature² death. And in the UK, previous research by the University of Oxford³ found around 33,000 lives a year could be saved if everyone in the UK followed dietary guidelines. Dr Peter Scarborough told the BBC: "According to our model, the biggest impact would be eating more fruit and veg. But this doesn't mean you should just stop at five – the more the better."However, there are some doubts about the 'five-a-day' message. Some fruits and vegetables are better than others. And counting orange juice, for example, as one of your portions isn't so beneficial because it contains sugar. Also, eating more vegetables than fruit tends to be better because they're richer in nutrients. Some doctors also say the message is too ambitious, and a 'two-a-day' message might be a more realistic starting point.

　　There have been calls to up the quota⁴ to seven-a-day, but research reported in The British Medical Journal found after five portions a day, there was no further impact. But whatever fruit and vegetables you consume, every piece can help reduce the risk of cardiovascular disease and cancer. As the old saying goes: 'an apple a day keeps the doctor away'.

　　词汇表

　　diet （日常）饮食

　　we are what we eat “人如其食”，想健康，得吃好intention 意愿

　　five-a-day “每天五份果蔬”，世界卫生组织为增强健康饮食意识而发起的每日至少食用 400g 水果或蔬菜的宣传活动balanced diet 均衡饮食

　　fruit 水果

　　vegetable 蔬菜

　　heart disease 心脏病

　　stroke 中风

　　cancer 癌，癌症

　　fibre （食物的）纤维素

　　vitamin 维生素

　　mineral 矿物质

　　nutrient 营养物

　　premature 过早的

　　dietary guidelines 膳食指南

　　beneficial 有益的

　　ambitious 要求过高的，需要极大努力才能完成的cardiovascular disease 心血管疾病

　　an apple a day keeps the doctor away “一天一苹果，医生远离我”，每天吃苹果有助于保持健康

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