英国新闻听力 饮食与人类行为（在线收听）

Diet and Human Action

Child: At dinner time I had chips, bottled milk, packing crisps and these little packet biscuits and a drink of tango, orange drink.

Woman: These kinds of industrial foods is very common now because it's easier to buy and just give the babies the food 1 preparing everything, uh, everyday.

Boy: I like the normal food but I will like to have some junk food at sometimes, twice a week.

Man: The industrialization of food has lead us to make unprecedented changes to human diet and unfortunately in doing so, we have made unprecedented changes to the brain's function and environment. Because 2 , what we eat is going to go directly into the blood supply.

Reporter: Over the last twenty thirty years, scientists have become more and more convinced about the link between our diets and the way we behave, feel and think. 3 , the industrialization of food has preceded a pace with little apparent consideration given to its possible impact on our brains. Previously research has suspected that the ingredients in highly processed foods, such as chemical additives were implicated in antisocial behavior for example. Now, increasingly a deficiency in the diet is seen as the bigger culprit. In this edition of the BBC Discovery program, we'll be looking at some of the latest evidence. Now critics argue that scientist are still foraging in the dark, the research has not yet made a convincing cast iron case linking specific individual nutrients to adverse affects on behavior and mood. And neither, is their agreement on the need for wide scale prescription of supplements, even so there is no shortage of people testifying to dramatic changes in behavior brought about by altering our diets. Bernert Gesh, from the University of Oxford is an expert in the field; he's worked in the UK's criminal justice system where the perpetrators of some crimes receive sentences that include a dietary prescription. Dr. Gesh recalls the remarkable case of a repeat offender who benefited from this enlightened system.

Dr. Bernet Gesh: All they ever use to do was steal trucks in the early hours of the morning, the call became some what exasperated with him because on the three occasions he was released from prison, he chose to steal a truck to return home. Now we assessed him and we 4 found that he had a condition known as flat curve hypoglycemia and indeed if you looked at his diet, his behavior it began to make a great deal of sense, because he was absolutely shoveling in stimulants such as coffee, sugar etc. and by the end of the day, which is when he was stealing the trucks, he, by his own admission was as high as a kite. And what was found was by giving him some supplements to improve his sugar control, he stopped offending.

Reporter: But, it not just about sugar intake, there's another major group of components of our diets which dominates the very fabric of the brain and it's functioning. The psychiatrist, Joseph Hibbeln of the U.S National Institutes of Health has been intrigued by them since his early days at medical school.

Joseph Hibbeln: When I was a medical student in the anthropotomy lab and a brain cut, and I held a brain, and I was looking at it and I said, what's these stuff made of? It's not protein, it's not bone, it's not muscle, this brain is made, almost entirely of fats and lipids. So, it was not to my mind a great jump to say, well if there was a biochemical abnormality regulating the composition of the lipids in the brain the brain might not function well. And as a 5 , I look at emotion and cognition and those human brain functions as a sign that the brain's not functioning well.

Reporter: So, lipids and fats are important components of the brain. And in recent years the attention of researchers have been drawn to the essential fatty acids, essential because we can't make them ourselves we have to have them in the food we eat. There are two main varieties the omega-3 fatty acids, are found in fish and other kinds of seafood and green leafy vegetables. Another type the omega-6's, are found in vegetables oils, nuts and grains, we need both of them but the balance between the two is crucial.

饮食与人类行为

孩子：晚饭时，我吃了炸薯条，瓶装牛奶，袋装薯片，还有这些小包装的饼干，喝了点tango牌饮料，还有橙汁。

女士：这些工业食品目前非常流行，因为它们买起来更方便，直接递给孩子们吃就可以了，不必每天大费周章的准备饭菜。

男孩：我喜欢吃家常饭，但是有时我也想吃点垃圾食品，大概一周两次吧。

男士：食品工业化已经给人类的饮食带来了空前的变革，但不幸的是，这样做让我们大脑的功能和它所处的环境也发生了空前的改变。因为，从根本上说，我们所吃的食物会直接进入我们的血液。

记者：在过去的二三十年里，科学家们越来越确信，我们的饮食与我们的行为，感觉和思想有所联系。同时，食品工业化的过快发展让我们在考虑这种饮食变化可能对人脑产生的影响上慢了一个节拍。以往的研究者已经开始怀疑，高度加工的食品成分，比如化学添加剂，可能与个体的孤僻行为之间存在联系。现在，人们越来越相信，饮食量的不足是导致这些问题的更主要原因。在本期的BBC《探索发现》节目中，我们带您了解一些最新证据。目前评论家认为，科学家们仍然在黑暗中摸索的阶段，现有的研究并没有找到一个令人信服的铁证案例，能够证明具体哪种营养成分会对人类行为和情绪造成负面影响。他们还否定了科学家们关于人体需要全面补充各种食物的说法。即便如此，还是有很多人正在努力证实，改变饮食习惯会给我们的行为带来巨大变化。牛津大学的伯尔尼特·盖什是该领域的专家，他在英国刑事审判系统工作。在该系统中，某些刑事案件的凶手接受的审判结果中专门有一项是规定犯人必须食用指定食物。盖什博士指出，在某个重要案件中，一位多次违法的罪犯正是由于受到这一开明系统的帮助，行为得到了很大改变。

伯尔尼特·盖什博士：他们过去所做的是在凌晨偷卡车，鸣笛声在某种程度上把他激怒了，因为在他三次从监狱获释后，他仍然选择偷一辆卡车回家。现在，经过评估，我们发现他有一种平缓曲线低血糖症。如果你观察他的饮食和行为规律，你就会发现它们确实存在联系。因为他在咖啡，糖等食物的刺激下，一定会产生异常情绪，尤其是在一天结束的时候，也就是他偷卡车的时候，连他自己都承认，他那时精神极度高亢。通过给他补充特定的饮食，提高其对糖分的控制，他果然停止了犯罪行为。

记者：但是，这不仅仅是糖分摄入的问题，我们的饮食中还有很多其他成分可以控制我们大脑的结构和功能。美国国家健康研究所精神病学专家，约瑟夫·希波尔恩自从早年在医疗学院学习时就对它们产生了浓厚的兴趣。

约瑟夫·希波尔恩：当我还是一名医疗学院的学生时，有一次在人体解剖实验室里，我拿着一个被切开的头颅。我看着它，不禁问道，它到底是由什么成分构成的呢？不是蛋白质，不是骨头，也不是肌肉，整个人脑几乎大部分结构都是脂肪和脂类化合物。于是我的脑海里灵光一闪，想到假如因为某些生物化学异常导致大脑中脂类化合物成分发生改变，那么人脑功能可能就无法正常运行。作为一名精神病学医师，我开始观察人们的情绪和认知状态，因为这些可以作为人脑功能是否正常的信号。

记者：这样看来，脂类化合物和脂肪是大脑的重要组成成分。在最近几年里，研究人员们主要把注意力集中在最基本的脂肪酸上。说它基本是因为我们人体无法自己制造这些脂肪酸，只能通过食物来摄取。脂肪酸主要有2种形式：omega-3脂肪酸主要存在于鱼类，其他海鲜食物，以及绿色蔬菜中；另一种脂肪酸omega-6主要存在于植物油，坚果和谷类食物中。这两种脂肪酸都是人体必需的，但两者之间的平衡也是至关重要的。