Mechanisms Linking Dairy to Higher Prostate Cancer Risk

乳制品与较高前列腺癌风险相关的机制

基本信息

批准号：
7127318
负责人：
MARILYN TSENG
金额：
$ 8.35万
依托单位：
FOX CHASE CANCER CENTER
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-09-29 至 2008-08-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Dairy food intake has been associated with prostate cancer in previous work, and the ecologic correlation between milk intake and prostate cancer mortality may be stronger than for any other dietary factor, including total fat. The mechanism by which dairy increases risk is unknown but includes two possibilities. First, dairy may elevate circulating levels of insulin-like growth factor I (IGF-I), a likely risk factor for prostate cancer. Second, dairy calcium may suppress circulating levels of potentially cancer-protective 1,25-hydroxyvitamin D (1,25-D). Other evidence suggests a possible difference in a dairy effect on 1,25-D levels by ethnicity and vitamin D status. The proposed work will evaluate the two hypotheses as possible explanations for observed associations between dairy and prostate cancer risk. We seek to test the hypotheses that dairy intake increases IGF-I levels but reduces circulating 1,25-D levels, that the effects are mediated by measurable dietary factors in dairy, and that effects on 1,25-D levels differ by ethnicity and vitamin D status. The study population will include 545 men enrolled in the Fox Chase Cancer Center Prostate Cancer Risk Assessment Program (PRAP) from 7/00 to 6/07. Men are eligible if they are 35-69 years old, have no history of prostate cancer, and, for non-African American men, have at least one 1st-degree relative with prostate cancer; no family history is required for African American men, who make up about half of the sample, because of their already elevated risk. Upon enrollment, men provide a blood sample and complete diet and health history questionnaires. Laboratory analyses will include assessments of plasma levels of IGF-I, insulin-like growth factor binding protein-3, 25-hydroxyvitamin D, and 1,25-D. These will be examined in relation to dairy foods and nutrients of interest as potential mediators, such as protein, calcium, and other minerals. We will also examine possible effect modification of the dairy-1,25-D association by ethnicity and vitamin D status. Given the enormous implications of observing an adverse health effect for dairy foods, a better understanding of the mechanisms by which dairy might increase prostate cancer risk is essential, providing biologic evidence to support a simple but potentially controversial preventive strategy. Findings will also provide information critical to African Americans, for whom a recommendation to reduce dairy may be harmful rather than beneficial.

描述（由申请人提供）：乳制品摄入量与先前工作中的前列腺癌有关，牛奶摄入量与前列腺癌死亡率之间的生态相关性可能比任何其他饮食因素（包括总脂肪）强。乳制品增加风险的机制尚不清楚，但包括两种可能性。首先，乳制品可能会提高胰岛素样生长因子I（IGF-I）的循环水平，这是前列腺癌的可能风险因素。其次，奶制钙可以抑制1,25-羟基维生素D（1,25-D）的循环水平。其他证据表明，乳制品对1,25-D水平的乳制作用可能存在差异。拟议的工作将评估这两个假设作为可能的解释，以解释乳制品和前列腺癌风险之间的关联。我们试图检验乳制摄入量增加IGF-1水平但降低循环1,25-D水平的假设，这些作用是由乳制品中可测量的饮食因素介导的，并且对1,25-D水平的影响因种族和维生素D状态而有所不同。该研究人群将包括545名从7/00到6/07的Fox Chase Cance Centrate Center Center Center Center Center Cancer Cancer Cancer Iss评估计划（PRAP）招收的男性。如果男性年龄35-69岁，没有前列腺癌的史，对于非非洲美国男性，至少有一个1度亲戚患有前列腺癌；非洲裔美国男性不需要家族史，因为他们已经升高了风险，因此占样本的一半。入学后，男性提供血液样本，完整的饮食和健康史问卷。实验室分析将包括评估IGF-I水平，胰岛素样生长因子结合蛋白-3，25-羟基维生素D和1,25-D。这些将与潜在介体（例如蛋白质，钙和其他矿物质）相关的乳制品和感兴趣的营养方面进行检查。我们还将通过种族和维生素D状态来检查乳制-1,25-d关联的可能效果修改。鉴于观察乳制品对健康效应的不利影响的巨大含义，对乳制品可能增加前列腺癌风险的机制有了更好的理解，这提供了生物学证据，以支持一种简单但潜在的有争议的预防策略。调查结果还将为非洲裔美国人提供至关重要的信息，为了减少乳制品的建议可能是有害而不是有益的。