食用油究竟要不要换着吃.doc

菜籽油、苎麻油、红棕榈油、南瓜油突然橄榄油在超市的货架有了许多竞争对手，但它们是否比我们一贯喜欢用的橄榄油更健康、更美味呢？罗伯特.哈德森用试验揭开了谜底。It was a day like any other, and I was in the super-market, reaching confidently for a bottle of extra virgin olive oil. I hadnt looked at the oil shelf properly for five years - olive oil tastes good, its part of the famously healthy Mediterranean diet, so what is there to think about? Suddenly though, my eye was caught by a dusky bottle of cold-pressed rapeseed oil. Next to it, I noticed the line of hemp, grapeseed, red palm and canola oils, all smartly packaged, all making strident health claims. I found myself twisting in bewilderment.Lately it seems the oil shelves have been invaded by new varieties. All naturally claim to be delicious, and, because olive oils success has been fuelled by its perceived health benefits, they all claim to be great for you too. So, for example, Hillfarm Extra Virgin Rapeseed oil trumpets its Delicious light nutty flavour before adding that it is very low in saturated fat, contains Omega 3, 6 + 9 and is free from artificial preservatives. It is an ideal oil for those concerned with their health and wellbeing.So, had my knee-jerk reliance on olive oil blinded me to a better, healthier, tastier way of life? After all, Omega 3 is important to the circulation and brain, and Omega 6 helps skin and hair (although excessive amounts have been linked to heart disease); both are found in rapeseed, avocado, hemp, pumpkin and walnut oils. Omega 9 is not essential. It has fewer demonstrated health benefits, and our bodies produce it from other unsaturated fats. Significantly, olive oil is full of Omega 9, but low in the other two. So do we need to switch?Dietitian Ursula Arens says no. These are important nutrients, but for essential fatty acids, there is no doubt that fish oils are the star. Vegetarians might need to consider getting some of their Omega 3 from vegetable oils, but they would need to eat large amounts.In fact, quantity is key. When it comes to health claims Arens says its highly unlikely that you will eat these oils in amounts that will make any difference. Many contain useful nutrients - vitamin E in avocado oil and plum seed oil, a wide range of amino acids in hemp oil - but, if youre using these in dressings once in a while, then all this is pretty irrelevant, nutritionally.The health arguments considered, I embarked on a taste test with Allegra McEvedy and her friend, Charles Carey, who has been importing oils for more than 20 years. First came a mouth-watering demonstration of the distinction between refined walnut oil and a cold-pressed virgin walnut oil from the A LOlivier mill in Poitiers. The dry, rich taste of the nut glowed warmly on the tongue. (In this context, virgin means that the oil is not mixed with any additive , where a virgin oil must have an acidity of less than 3%.)Carey then moved on to a rapeseed oil. Most vegetable oil sold in the UK is actually made from rapeseed, but its become fashionable to lose that general label, and sell these oils as extra virgin rapeseed oil, or cold-pressed varieties.I have to laugh, says Charles. These descriptions have legal standing for olive oils, but rapeseed guys are mainly using them because they sound good. We try an organic rapeseed oil from Brittany, called Troustain Barville, which Allegra describes as grassy and Charles calls brassica-ish. Its not unpleasant, but its difficult to see why you would choose it over the alternatives.We discuss hemp oil, which, as you might expect, tastes grassy, and a bit overpowering, and palm oil, which is basic to much African and West Indian cookery, but is a bit too rich for our palates. Allegra regards avocado oil as pointless. If you want something oily which tastes of avocado, eat an avocado.Next up are two oil wildcards: plumseed and coffee. Its claimed that plum seed oil can be used in salad dressing, but, on trying it, the idea seems slightly bizarre. The taste is less fierce than the overpowering marzipan bouquet suggests, but still Allegra says, Crikey! This is like instant frangipane! You could use it as a baking ingredient, I suppose.As for the coffee oil - the result of olives and coffee beans being pressed together by the Spanish olive oil producer Vea - again it is pungent, almost acrid. The bottle comes with a hopeful collection of recipes, many of which seem to infer that coffee and seafood are natural bedfellows: shrimps in a mint coffee sauce and sea bream with vinaigrette and coffee oil, for instance. A couple, including ice cream, and an endive and nut salad, sound OK, but really, would you bother?Frankly, no, says Allegra, explaining that she sticks to groundnut oil for Asian food, and nice walnut oil is great in a dressing or for adding depth to stews. Shes impressed when we try an A LOlivier grapeseed oil, which causes her to exclaim Oh, this is really fresh!, before Charles explains that he uses it for mayonnaise.I can see a use for that, she agrees, but Im not convinced by the others.Me neither. As Arens says, the nutritional benefits are, for the most part, negligible, and while you could find occasional use for some of these oils - potatoes roasted in virgin rapeseed oil are fresh and light - none could replace olive oil for kitchen versatility. My head may have been briefly turned, but Ill stick to my old favourite.那天，在超市里，像往常一样，我满怀信心地把手伸向放特级初榨橄榄油的货架。实际上在过去的五年里我基本上没关注过放食用油的货区，因为橄榄油味道很好，它是闻名的地中海健康饮食的一部分，所以有什么好犹豫的呢？但是，突然我的眼睛被一瓶颜色较深的冷榨菜籽油吸引。在它旁边，我注意有一溜儿的苎麻油、葡萄籽油、红棕榈油和油菜籽油，它们包装都很精美，瓶身上都有食用如何如何健康的描述。这时我发现自己很难抉择了。最近似乎食用油货架已被新品种侵入了。所有的油都声称天然、美味，而且由于被认为对健康有益促进了橄榄油的成功，他们也都声称自己最适合你。比如，Hillfarm特级初榨菜籽油宣传自己“低饱和脂肪，含有欧米加3 、6 、9、不含人工防腐剂”，鼓吹自己“有怡人的清新坚果气息”，是“那些关注自身健康和幸福人士的理想食用油。”那么，是潜意识依赖橄榄油使我无视一个更美好、更健康、更美味的生活方式吗？毕竟，欧米加3对血液流通和大脑很重要，欧米加6有助于皮肤和头发（尽管摄入过量有患心脏病的风险）；它们在菜籽油、鳄梨油、苎麻油、南瓜油、核桃油里都有。欧米加9是非必需的，它很少表现对健康的好处，我们的身体能从其他不饱和脂肪中自己合成。值得注意的是，橄榄油富含欧米加9 ，但其他两个的含量较低，所以我们需要换其他油吗？营养师乌尔苏拉.阿伦斯说不用。“这些都是重要的营养物质，但对于必需脂肪酸，毫无疑问，鱼油应排在首位。素食主义者可能需要考虑从植物油中摄取一些欧米加3，但他们将需要吃大量的油分。”事实上，数量是关键。说到健康宣传，阿伦斯说，“你将吃的这些油的数量不可能有任何区别。”许多都包含有用的营养素鳄梨油和梅子籽油里的维生素E，苎麻油里有各种各样的氨基酸但是，“如果你只是做为饮食的辅料偶尔用上一点点，这跟营养没什么相干。”考虑到对健康的的争议，我和艾丽格拉.麦克伊韦迪以及她做了二十多年食用油出口生意的朋友查尔斯.凯里着手进行了口味测试。首先我们做了令人垂涎三尺的示范，以显示精制核桃油和来自波亚提尔橄榄油小镇的冷榨初级胡桃油的区别，浓浓的果香味在舌间微微荡漾。（在本文中，“初榨”指没有与任何添加剂混合，初榨的油必须含不少于3%的酸度。）然后凯里接着实验菜籽油，英国大多数植物油产品实际上是由菜籽油制成的，但把这些油作为特级初菜籽油或冷榨油品出售，不用菜籽油标签成为时髦的事。“我不得不笑了，”凯里说，“对于橄榄油的那些描述有法定依据，但造油菜籽的那些人主要是利用它们，因为这些文字听起来不