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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）：在之前的研究中，乳制品摄入量与前列腺癌有关，并且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）更强。乳制品增加风险的机制尚不清楚，但有两种可能性。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，这可能是前列腺癌的危险因素。其次，乳制品中的钙可能会抑制具有潜在抗癌作用的 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 水平的影响可能因种族和维生素 D 状况而异。拟议的工作将评估这两种假设，作为观察到的乳制品与前列腺癌风险之间关联的可能解释。我们试图检验这样的假设：乳制品摄入量会增加 IGF-I 水平，但会降低循环 1,25-D 水平，这种影响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 状态而异。研究人群将包括 7 月 00 日至 6 月 7 日期间参加福克斯蔡斯癌症中心前列腺癌风险评估计划 (PRAP) 的 545 名男性。男性年龄在 35-69 岁之间，没有前列腺癌病史，并且对于非非裔美国男性，至少有一名一级亲属患有前列腺癌，则符合资格；占样本一半左右的非裔美国男性不需要家族史，因为他们的风险已经很高。登记后，男性提供血液样本并填写饮食和健康史调查问卷。实验室分析将包括评估 IGF-I、胰岛素样生长因子结合蛋白 3、25-羟基维生素 D 和 1,25-D 的血浆水平。这些将被检查与乳制品和作为潜在介质的感兴趣的营养素（例如蛋白质、钙和其他矿物质）的关系。我们还将研究种族和维生素 D 状况对乳制品 1,25-D 关联的可能影响修正。鉴于观察乳制品对健康的不利影响的巨大影响，更好地了解乳制品可能增加前列腺癌风险的机制至关重要，从而提供生物学证据来支持简单但可能存在争议的预防策略。研究结果还将为非裔美国人提供至关重要的信息，对他们来说，减少乳制品的建议可能有害而不是有益。