Plant-based diets and risk of cancer

描述（由申请人提供）：在2002-2007年期间，我们组建了一个大型队列（N= 96，000），名为复临健康研究-2（AHS-2）。该队列包含25，000名黑人受试者，并且来自美国所有50个州以及加拿大所有省份和地区的所有社会阶层的广泛代表性。大约45%的人是素食主义者，但另外25%的人平均每天消耗139克肉类。因此一个很重要的特点就是饮食习惯广泛。这项工作的主要目标是首先评估与杂食性饮食相比，植物性饮食与结直肠癌，乳腺癌和前列腺癌风险之间的关联，因为以前的工作表明这些存在。接下来关注营养素，植物化学物质，维生素和这些饮食模式之间不同的食物组，包括红肉，西红柿，乳制品，十字花科蔬菜，芦荟酮，长链脂肪酸等。这一人群对大多数水果和蔬菜的摄入量相对较高，大豆的消费量接近亚洲水平，并且具有高摄入量和高脂肪水平的n-3脂肪酸。这一人群中的许多关键饮食暴露量的方差似乎是其他知名研究人群的1.5- 3倍。这意味着人口的统计能力是AHS-2名义规模的1.5- 3倍，表明这是一项非常具有成本效益的研究。每个研究成员都完成了一份50页的问卷，其中包括饮食细节，病史，体育活动，女性历史和人口统计学。一个大的和全面的校准研究的1011个代表性的主题已经形成，以验证膳食摄入量的估计，并促进回归分析中的测量误差校正。从校准研究受试者收集的数据包括6次仔细定时的24小时饮食回忆、第二次食物频率问卷、两次一周体力活动回忆以及一组异常丰富的生物样品，从中估计生物标志物：血清、血浆、血沉棕黄层、RBC、过夜尿液和皮下脂肪抽吸物。对于测量误差校正，将使用传统的回归校准，以及一个创新的最近发表的生物标记引导校准方法。根据需要，我们从校准研究数据中估计了大量的摄入生物标志物。许多与饮食回忆的相关性相对较高。问卷饮食指数的有效性（与回忆相比）也符合其他人的最佳经验。通过与州癌症登记处进行匹配，以及作为次要来源的两年一度的问卷调查，发现了癌症事件。初步估计，我们将错过这些癌症中的2.5%。今后五年计划开展的主要活动类别是：a）继续并完成对癌症发病率的检测; B）继续编写年度通讯，以及促进队列保留的流行文章，并保持最新的联系信息; c）最后也是最重要的是，完成分析并编写涉及所列具体目标的手稿。 公共卫生相关性：乳腺癌、结肠直肠癌和前列腺癌每年折磨着超过55万美国人，并导致近12万人死亡。这项研究将通过使用一个异常信息丰富的美国研究人群，提供关于植物性饮食模式（包括肉类消费）在增加或降低这些癌症风险方面的潜在作用的更明确的答案。由于这一人群中的许多人也吃大量的许多特定的蔬菜食品，我们也可以将这些食物的摄入与癌症风险联系起来。人们非常关注提高估计的准确性。

DESCRIPTION (provided by applicant): Between 2002-2007 we assembled a large cohort (N= 96,000) named Adventist Health Study-2 (AHS-2). The cohort contains 25,000 Black subjects, and also has a broad representation from all social classes, from all 50 states of the U.S. and all provinces and territories of Canada. About 45% are vegetarian, but another 25% on average consume 139 gm of meat per day. Thus a very important feature is a wide range of dietary habits. The main goals of this work are to first evaluate associations between plant-based compared to omnivorous diets on risks of colorectal, breast and prostate cancers, as previous work suggests that these exist. Next to focus on nutrients, phytochemicals, vitamins and food groups that differ between these dietary patterns, including red meat, tomatoes, dairy foods, cruciferous vegetables, isoflavones, long-chain fatty acids, and others. This population has a relatively high intake of most fruits and vegetables, a consumption of soy that approaches Asian levels, and has both high intake and high adipose levels of n-3 fatty acids. Many key dietary exposures in this population appear to have a variance that is 1.5- 3 times that of other well-known study populations. This translates to the statistical power of a population 1.5--3 times the nominal size of AHS-2, indicating that this is very cost-effective research. Each study member has completed a 50 page questionnaire that covers diet in detail, also medical history, physical activity, female history, and demographics. A large and comprehensive calibration study of 1011 representative subjects has been formed to validate the estimation of dietary intake, and also to facilitate measurement error correction in regression analyses. Data collected from calibration study subjects includes 6 carefully timed 24-hour dietary recalls, a second food frequency questionnaire, two one week physical activity recalls, and an unusually rich group of biological samples from which to estimate biomarkers: serum, plasma, buffy coat, RBCs, an overnight urine, and a subcutaneous fat aspirate. For measurement error correction, traditional regression calibration will be used, as well as an innovative recently published biomarker-guided calibration method. As required for this, we have estimated a large number of biomarkers of intake from the calibration study data. Many correlations with dietary recalls are relatively high-valued. The validity of questionnaire dietary indices (compared to recalls) is also in keeping with the best experience of others. Incident cancers are found by matching with state cancer registries, and also from biennial questionnaires as a secondary source. Initial estimates suggest we will miss only 2.5% of these cancers. The main categories of activity planned during the next 5 years are to a) continue and complete the detection of incident cancers; b) continue the production of an annual newsletter, also popular articles to promote cohort retention, and maintain up-to-date contact information; c) finally and most importantly, complete analyses and produce manuscripts that address the listed specific aims. PUBLIC HEALTH RELEVANCE: Breast, colorectal and prostate cancers afflict more than 550,000 Americans each year and kill nearly 120,000. This research will provide more definitive answers about the potential roles of plant-based dietary patterns, also meat consumption, to either increase or decrease risks of these cancers, by using an unusually informative U.S. study population. As many in this population also eat greater quantities of many particular vegetable foods, we can also associate intake of these with cancer risk. Great attention is given to improving accuracy of estimates.