每天10個果 醫生遠離你
I have just eaten a delicious conference pear weighing about 180g. I do not normally weigh snacks, but the recently reported health benefits of eating more fruit and vegetables has inspired me to dig out the scales.
我剛吃了一枚重約180克的梨子，很好吃。我通常不會稱零食的重量，但最近看到有關多吃水果和蔬菜有益健康的報道後，我把秤找了出來。A study published last month showed that, as expected, people who eat fruit and vegetables regularly cut their risk of dying from several diseases such as stroke, cancer and heart disease. Generally, the higher the intake of fruit and vegetables, the lower the risk.
2月發表的一項研究表明，正如預期的那樣，經常吃水果和蔬菜，能降低死於中風、癌症和心臟病等幾種疾病的風險。一般而言，水果和蔬菜攝入量越高，這種風險就越低。Here’s the new bit, according to the paper in the International Journal of Epidemiology, the optimum intake was about 800g per day. Since 80g counts as one serving — roughly one small banana or pear, or three heaped tablespoons of cooked veg — this equates to 10 portions. Given that two out of three Britons struggle to hit the recommended target of five a day, the news that we should now be aiming for 10 was greeted with incredulity.
根據《國際流行病學雜誌》(International Journal of Epidemiology)的這篇文章，新的發現是，最優攝入量是每天約800克。由於80克算一份——差不多是一根小香蕉或小個兒梨子，或滿滿3大湯匙煮熟的蔬菜——800克相當於10份。鑑於三分之二的英國人連每天5份的推薦攝入量都難以達到，每天應該爭取吃10份的消息讓人覺得匪夷所思。
Researchers from Norway, the UK and US pooled data from 95 separate studies, involving a total of about 2m people. Each of those studies had one thing in common: they asked participants about their dietary intake and measured health outcomes, such as rates of cancer, stroke or heart disease.
來自挪威、英國和美國的研究人員彙集了95項獨立研究的數據，覆蓋約200萬研究對象。每項研究都有一個共同點：他們向參與者詢問他們的飲食攝入量，並衡量健康結果，比如癌症、中風或心臟病的發病率。What works
什麼管用A meta-analysis of that pooled data suggested that, compared with eating no fruits and vegetables, overall health outcomes improve with every 200g increment, up to 800g (up to 600g for those with cancer). Unsurprisingly, few people manage to eat more than 800g, meaning that scientists are unable to reliably investigate the benefits of higher intakes (which, I assume, accrue mainly to toilet-roll manufacturers).
對這些彙總數據的薈萃分析表明，與不吃水果和蔬菜相比，攝入量每增加200克，總體健康狀況就會有所改善，直至達到800克（對於癌症患者，最高爲600克）。不出所料，很少有人的攝入量能超過800克，這意味着科學家們無法可靠地研究更高攝入量的益處（我猜，這主要對衛生捲紙廠商有好處）。Even so, modest amounts seem to make a difference. Eating 200g of fresh produce (about two-and-a-half portions) appeared to cut the risk of cardiovascular disease by 13 per cent; the risk of dying from cancer by 4 per cent; and the risk of premature death by 15 per cent.
即使如此，適當的攝入量似乎是有作用的。吃200克新鮮農產品（約2.5份），似乎把患上心血管疾病的風險降低13%；把死於癌症的風險降低4%；把早亡風險減低15%。Upping daily intakes to 800g brings even better news: a 28 per cent reduction in risk of cardiovascular disease; a 13 per cent reduction in total cancer risk; and a 31 per cent cut in the risk of premature death. Dr Dagfinn Aune from Imperial College’s School of Public Health, who led the analysis, estimated that about 7.8m deaths worldwide per year could be prevented if people ate 10 a day.
每天攝入量達到800克會帶來更好的消息：心血管疾病風險減少28%；總體癌症風險降低13%；早亡風險降低31%。牽頭這項研究的帝國理工學院(Imperial College)公共衛生學院(School of Public Health)的達芬?奧納(Dagfinn Aune)博士估計，如果每天吃10份水果和蔬菜，那麼全世界每年的死亡人數有望減少約780萬。What to eat?
該吃什麼？Some fruits and vegetables seemed especially protective for certain conditions. Those wanting to fend off early death, particularly from stroke or heart disease, could add the following to their plates: apples, pears, citrus fruits, spinach, lettuce, chicory, and cruciferous vegetables such as broccoli, cabbage and cauliflower. For cancer, the researchers suggested a possible benefit from green and yellow vegetables, such as peppers and green beans and, again, cruciferous vegetables.
一些水果和蔬菜似乎對某些疾病尤其具有防範作用。想要防止早亡（特別是中風或心臟病引起的早亡），可以在盤子中添加以下東西：蘋果、梨、柑橘類水果、菠菜、萵苣、菊苣以及十字花科蔬菜，比如西蘭花、捲心菜和花菜。對於癌症，研究人員提出綠色和黃色蔬菜（如甜椒和四季豆）以及十字花科蔬菜可能有益。This study shows a correlation rather than causation. The researchers have not proved that dining on fresh produce fends off death and disease; it could be that people who eat more healthily also exercise more and are less likely to smoke, with these confounding behaviours really responsible for their rude health. The fact, however, that incrementally higher intakes were associated with incrementally lower risks, though, adds weight to the idea that a healthy diet plays a role.
這項研究顯示了關聯度，而不是因果關係。研究人員還沒有證明，食用新鮮農產品可以防範死亡和疾病；可能情況是，那些吃得更健康的人也會鍛鍊得更多，而且不太可能吸菸——這些組合行爲造就了他們的良好健康。然而，遞增的攝入量與逐漸降低的風險存在關聯的事實，增加了健康飲食起作用的說法的可信度。Other research points to mechanisms by which fruits and vegetables work their therapeutic magic. They are known to reduce cholesterol and blood pressure, and to contain antioxidants that help to repair DNA damage. This last factor is thought to have a bearing on cancer risk. Tumours usually begin with rogue cells whose growth can’t be kept in check.
其他研究指向了水果和蔬菜發揮其神奇療效的機制。人們已知道，水果和蔬菜可以降低膽固醇和血壓，並含有抗氧化劑，有助於修復受損DNA。DNA受損據信與癌症風險有關。腫瘤通常始於生長失控的“流氓細胞”。Dr Aune said that, even though further research was needed to pin down the details, “a high intake of fruit and vegetables holds tremendous health benefits, and we should try to increase their intake in our diet”.
奧納博士表示，儘管需要進一步的研究來確定細節，但“大量攝入水果和蔬菜對健康有很大的好處，我們應該努力在飲食中增加它們的攝入量”。Whole plant foods beat processed versions such as smoothies, which can be high in sugar. Nutritional supplements are no substitute; Dr Aune said there was no evidence they cut the risk of disease.
天然植物食物勝過冰沙等加工食品。沙冰的含糖量可能很高。營養補充品不能替代蔬菜水果；奧納博士說，沒有證據表明營養補充品會降低患病風險。
The verdict
結論Headlines might have suggested otherwise but the new paper, persuasive though it is, did not prompt a change in the official five-a-day message. This is pragmatic: those already managing five are health-conscious and self-motivated enough to raise their cruciferous-munching ambitions without official haranguing. Those who are not yet heeding the message would risk becoming disheartened at the sudden shifting of the nutritional goalposts.
新聞標題也許給人留下不同印象，但是這篇新論文雖有說服力，卻並未促使官方調整每天5份的推薦攝入量。這是務實的：那些每天已攝入5份的人很重視健康，他們會自我激勵，即使沒有官方的強力說教，也會提高十字花科蔬菜攝入量的目標。而那些攝入量還不到5份的人，對營養目標的突然上調可能感到沮喪。Anyway, back to the scales. With each pear clocking in at nearly 200g, I did fleetingly wonder whether I could tick off my 800g with three more ripe beauties from the fruit bowl, currently sitting atop two wrinkly apples and an unappealing banana. Alas not — the biggest benefits come from eating a variety of fruits and vegetables, with their corresponding panoply of nutrients. My ugly fruit friends: your time has come.
無論如何，再說回到秤吧。鑑於每隻梨的重量接近200克，有一個念頭在我腦海裏短暫閃現：我要不要再吃三個美味的熟梨，以便一口氣達到800克的單日目標？眼下這些梨就在我面前的果盤裏，躺在兩個皺巴巴的蘋果和一根難看的香蕉上。但是不行——最大的健康效益來自於食用多種水果和蔬菜，吸取它們各自蘊含的營養成分。我的醜陋的水果朋友們：吃掉你們的時間到了。
