Health of vegetarians

素食者的健康：通俗概述EPIC-Oxford是一项追踪素食者和类似的非素食者健康状况的大型研究。这项拟议的研究旨在调查英国素食主义者的长期健康状况。这将有助于了解几个相关的饮食因素对长期健康的影响，并将为生活在英国的120万素食者提供重要信息。EPIC-牛津大学的参与者包括65,500名男性和女性，他们在20世纪90年代自愿加入这项研究。招募对象是素食主义者和其他对饮食感兴趣的人，34,000名肉食者、10,000名吃鱼不吃肉的人、19,000名乳类素食者和2,500名素食者参加了这项研究。所有参与者都完成了一份关于他们的饮食和生活方式其他方面的问卷，其中2万人还提供了一份血液样本，将其冷藏起来，以供未来分析。参与者的饮食和生活方式在招募5年、10年和15年后完成了问卷调查，他们的健康状况随后与英国国家医疗服务体系关于医院诊断、癌症和死亡的数据联系在一起。EPIC-牛津大学之前的分析表明，素食者和非素食者在饮食摄入量、营养状况或其他健康指标方面存在很大差异。这些差异中的一些可能会导致素食者更好的健康，而另一些可能会导致更差的健康。例如，我们已经证明，素食者超重和肥胖的水平相对较低，血液胆固醇较低，水果和蔬菜的摄入量较高，纤维摄入量较高，所有这些都可能降低患某些类型心脏病的风险，或许还有其他疾病。相比之下，我们还表明，素食者的饮食摄入量和血液中潜在有益类型的脂肪(特别是来自鱼类的n-3脂肪酸)、维生素B12和维生素D的水平较低；这些低水平可能导致素食者患某些疾病(如中风)的风险增加。这项拟议的研究将利用我们在过去20年中收集的关于EPIC-Oxford参与者的饮食和生活方式的信息，并通过与国家卫生服务数据的持续链接进行扩展跟踪，以检查素食者与非素食者相比患一系列疾病的风险。检查的主要饮食因素将是素食和纯素食。我们还将研究肉类、鱼类、乳制品、动物蛋白、乳蛋白、饱和脂肪、植物油和鱼类脂肪、膳食纤维、维生素B12和钙对健康的影响。然后，我们将检查参与者的健康记录，以回答几个问题：已报道的素食者患缺血性心脏病的风险低是否主要是由于饱和脂肪酸的摄入量较低，以及是否也可能受到其他饮食因素的影响，如肉类中的特定化合物。素食者中风的风险是否可能较高，这可能与从动物性食物中摄取蛋白质和维生素B12的摄入量较低有关。纯素食者和其他钙摄入量低的人，由于乳制品摄入量低或为零，骨折的风险可能很高。由于动物蛋白的摄入量较低，素食者患骨关节炎关节置换的风险可能较低。素食者患消化系统疾病的风险可能较低，主要原因是膳食纤维的摄入量较高，且不吃肉。

Health of vegetarians: lay summaryEPIC-Oxford is a large study following the health of vegetarians and similar non-vegetarians. The aim of the proposed research is to examine the long-term health of vegetarians in the UK. This will help understanding of the impact of several related dietary factors on long-term health, and will provide important information for the 1.2 million vegetarians living in the UK. The participants in EPIC-Oxford comprise 65,500 men and women who volunteered to join the study in the 1990s. Recruitment was targeted at vegetarians and other people with an interest in diet, and 34,000 meat-eaters, 10,000 people who eat fish but not meat, 19,000 lacto-vegetarians and 2,500 vegans joined the study. All the participants completed a questionnaire about their diet and other aspects of lifestyle, and 20,000 of them also provided a blood sample to be stored frozen for future analysis. The diet and lifestyle of the participants has been followed by questionnaires completed 5, 10 and 15 years after recruitment, and their health has been followed by linkage to National Health Service data on hospital diagnoses, cancers and death.Previous analyses in EPIC-Oxford have shown several large differences in dietary intake, nutritional status or other markers of health between vegetarians and non-vegetarians. Some of these differences might be expected to lead to better health in the vegetarians, whereas others might lead to worse health. For example, we have shown that the vegetarians have relatively low levels of overweight and obesity, low blood cholesterol, high fruit and vegetable intake and high fibre intake, all of which may reduce the risk for some types of heart disease and perhaps other diseases. In contrast, we have also shown that the vegetarians have low dietary intakes and blood levels of potentially beneficial types of fat (especially n-3 fatty acids from fish), vitamin B12 and vitamin D; these low levels might contribute to an increased risk in vegetarians for some diseases, such as stroke. The proposed research will utilize the information we have already collected over the last 20 years on the diet and lifestyle of the participants in EPIC-Oxford, together with extended follow-up by continued linkage to data from the National Health Service, to examine the risk for a range of diseases in vegetarians compared to non-vegetarians. The main dietary factors examined will be vegetarian and vegan diets. We will also examine the impact on health of meat, fish, dairy products, animal protein, dairy protein, saturated fats, fats from vegetable oils and fish, dietary fibre, vitamin B12, and calcium. We will then examine the health records of the participants to answer several questions:Whether the already reported low risk of ischaemic heart disease in vegetarians is largely due to the low intake of saturated fatty acids, and whether it may also be affected by other dietary factors such as particular compounds in meat.Whether the risk of stroke may be high in vegetarians, and this may be related to the low intake of proteins from animal foods and of vitamin B12. Fracture risk may be high in vegans and other individuals with low intakes of calcium due to low or zero intakes of dairy products. The risk for joint replacement for osteoarthritis may be low in vegetarians, due to low intakes of animal protein.The risk of several disorders of the digestive system may be low in vegetarians, primarily due to high intakes of dietary fibre and absence of meat.