Plant-based diets and risk of cancer

描述(申请人提供)：2002-2007年间，我们收集了一个大型队列(N=96,000)，名为基督复临安息日健康研究-2(AHS-2)。该队列包含25,000名黑人受试者，也有来自美国所有50个州和加拿大所有省和地区的所有社会阶层的广泛代表。大约45%的人是素食主义者，但另有25%的人平均每天消费139克肉类。因此，一个非常重要的特点就是广泛的饮食习惯。这项工作的主要目标是首先评估植物性饮食和杂食性饮食与结直肠癌、乳腺癌和前列腺癌风险之间的关系，因为以前的工作表明这些风险是存在的。接下来重点关注营养素、植物化学物质、维生素和不同饮食模式的食物类别，包括红肉、西红柿、乳制品、十字花科蔬菜、异黄酮类、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，n-3脂肪酸的摄入量和脂肪水平都很高。这一人群中许多关键的饮食暴露似乎存在差异，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名义大小的1.5-3倍，这表明这是非常划算的研究。每个研究成员都完成了一份50页的调查问卷，其中包括详细的饮食、病史、体力活动、女性病史和人口统计数据。对1011名有代表性的受试者进行了一项大型而全面的校准研究，以验证对膳食摄入量的估计，并便于回归分析中的测量误差校正。从校准研究对象收集的数据包括6个精心安排的24小时饮食召回、第二个食物频率问卷、两个一周的体力活动召回，以及一组异常丰富的生物样本，从这些样本中可以估计生物标志物：血清、血浆、黄褐色外套、红细胞、夜间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，以及最近发布的一种创新的生物标志物引导校准方法。为此，我们从校准研究数据中估计了大量摄入量的生物标志物。与饮食召回的许多相关性相对较高。问卷饮食指数的有效性(与召回相比)也与其他人的最佳经验一致。事故癌症是通过与州癌症登记匹配来发现的，也可以从作为次要来源的两年一次的调查问卷中发现。初步估计，我们只会漏掉其中2.5%的癌症。计划在今后5年内开展的主要活动类别是：a)继续并完成对癌症发病情况的检测；b)继续出版一份年度通讯，并出版热门文章，以促进保留队列，并保持最新的联系信息；c)最后，也是最重要的，完成分析并编写针对所列具体目标的手稿。

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.