VB可以推迟老年痴呆症的发作.doc

Vitamin B supplements could delay onset of Alzheimers, says study | Life and style | The GuardianTaking daily supplements of B vitamins may delay the onset of Alzheimers disease, scientists have claimed.The discovery that people in the early stages of failing memory can retain more of their mental faculties for longer if they take the tablets regularly could lead to treatments for the condition. Some participants in the Oxford University trial saw their neurological decline reduced by as much as half after using B vitamins.That breakthrough has raised hopes that the vitamins, which are sold in chemists and health food stores, could at least slow down, if not prevent, the shrinkage that affects many older peoples brains.Vitamin B tablets are popular among vegans, because they shun some of the foods in which vitamin B is found fish, meat and milk and among sufferers of pernicious anaemia.It is our hope that this simple and safe treatment will delay the development of Alzheimers in many people who suffer from mild memory problems, said David Smith, a professor emeritus in Oxford Universitys pharmacology department and co-leader of the study. About 1.5m people over 70 in the UK who suffer from mild cognitive impairment (MCI) who have a 50/50 chance of going on to develop full-blown dementia within five years could benefit from the discovery, Smith added. But while the results were immensely promising, it was not yet certain, he stressed, if B vitamins could slow or prevent the development of Alzheimers. See footnoteHealthy middle-aged people hoping to avoid dementia and older people exhibiting early signs of memory loss might now be tempted to start routinely taking the vitamins, he said. But they should not do without first talking to their doctor, as the tablets could help stimulate the growth of early-stage cancer, he warned.Chris Kennard, chair of the neurosciences and mental health board at the Medical Research Council, said the findings bring us a step closer to unravelling the complex neurobiology of ageing and cognitive decline and hold the key to the development of future treatments for conditions like Alzheimers disease.Rebecca Wood, chief executive of the Alzheimers Research Trust, said: These are very important results, with B vitamins now showing a prospect of protecting some people from Alzheimers in old age. The strong findings must inspire an expanded trial to follow people expected to develop Alzheimers, and we must hope for further success.Some 820,000 people in the UK have dementia, predominantly Alzheimers, and their numbers are expected to soar as the population ages.Smith and his colleagues at the Oxford Project to Investigate Memory and Ageing gave one group of people with MCI daily tablets comprising folic acid, vitamin B6 and vitamin B12, and another group a placebo. The vitamins were chosen because they control the amounts of an amino acid called homocysteine in the blood. High levels of homocysteine have been linked to a greater risk of Alzheimers.After two years participants brains were examined using MRI scanners and their mental faculties assessed using tests of cognition. They found that those who had been receiving the supplements had experienced on average 30% less brain atrophy than those receiving the dummy pills. The former saw their brains shrink by 0.76% a year, while the placebo group saw theirs reduce by 1.08%. Those who started the trial with the highest levels of homocysteine experienced the greatest benefit 50% less brain shrinkage. This footnote was added on 9 September 2010. The study findings were published in an open-access journal, Public Library of Science ONE. A reference in the story text to vegans has been amended to make clear that fish, meat and milk are not the only foods containing significant amounts of vitamin B. 研究发现，补充维生素B可以推迟老年痴呆症的发作科学家称，每日服用维生素B可以推迟老年痴呆症的发作。研究发现，早期失忆的人如果有规律地服用维生素B进行治疗，可以更长时间地保持记忆力。牛津大学实验的参与者发现在服用维生素B后，他们的神经下降变为原来的一半。这个突破性的发现使人们找到了在药店和保健品店都有售的维生素，如果不能阻止，至少是减缓许多老年人大脑萎缩的希望。维生素B药片在素食者中很常见，因为他们不吃一些含有维生素B的食物鱼，肉和牛奶，恶性贫血患者也是。“我们希望这种简单，安全的治疗方法可以减缓老年痴呆症在许多遭受中度记忆问题人群中的发展，”大卫斯密斯（David Smith）说，他是牛津大学药理学系退休教授，也是此项研究的领导者之一。英国有大约150万70岁以上老人患有轻度认知障碍（MCI），这些患者在5年内有50%的可能恶化成完全痴呆。他们可以从此次发现中受益，斯密斯补充说。他强调，虽然结果是“非常有前途的”，但还没有确定维生素B是否能减缓或阻止老年痴呆症的发展。他说，健康的中年人希望规律地服用维生素来避免痴呆和老年时出现的早期记忆丢失症状。但是他们首先应该和医生沟通，因为这些药片有可能导致早期癌症生长，史密斯同时警告说。克里斯柯纳德（Chris Kennard），医学研究委员会神经科学和心理健康委员会主席，说该发现“让我们进一步解开了认知下降的神经生物学机理和开发治疗老年痴呆症方法的关键。”瑞贝卡伍德，老年痴呆症研究基金会首席执行官，说：“这是非常重要的研究成果，维生素B可以预防老年痴呆症。这项发现会激励研究人员继续跟踪患有老年痴呆症的人，我们希望可以获得更大的成功。”英国有大约82万人患有痴呆，主要是老年痴呆症，随着年龄增长，人数还在增加。史密斯和他在牛津大学研究记