一天“十苹果”，疾病远离我？

一天“十苹果”，疾病远离我？

健康饮食越来越受到人们的重视，最近的科学研究表明如果每人每天吃重量相当于十个苹果左右的水果蔬菜，患心血管疾病和癌症的几率将大大下降。可是问题是吃什么，该怎么吃——毕竟不是每个人都能持之以恒的每天吃“十个苹果”。

测试中可能遇到的词汇和知识：

epidemiology流行病学；传染病学[,epɪdiːmɪ'ɒlədʒɪ]

optimum最适宜的['ɒptɪməm]

incredulit怀疑；不轻信[ɪnkrə'djuːlətɪ]

increment增量；增加['ɪŋkrɪm(ə)nt]

cardiovascular心血管的[,kɑːdɪəʊ'væskjʊlə]

cruciferous十字花科的[kru:'sifərəs]

therapeutic治疗的[,θerə'pjuːtɪk]

harangue长篇大论；高谈阔论；慷慨陈词[hə'ræŋ]

London's share of global IPOs lowest since 2012（453 words）

By Thomas Hale and ZosiaWasik

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.

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.

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.

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.

What works

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).

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.

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 DagfinnAune 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.

What to eat?

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.

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.

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.

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”.

Whole plant foods beat processed versions such as smoothies, which can be high in sugar. Nutritional supplements are no substitute; DrAune said there was no evidence they cut the risk of disease.

The verdict

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.

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.