Antioxidant nutrients and Oxidative DNA Damage in Afric*

描述(由申请人提供)： 癌症是美国第二大死因，非裔美国人的发病率和死亡率高于其他种族或民族。研究表明，氧化应激可能与许多慢性病的发生有关，例如癌症，而抗氧化剂的营养状况与各种癌症的发生成反比。然而，关于健康人群中抗氧化营养素和氧化应激之间可能存在的种族差异的信息有限，需要改进方法学，在基于人群的流行病学研究中准确评估自我报告的抗氧化营养素摄入量。该项目的假设是，非裔美国人血液中的抗氧化营养素水平低于白人，而氧化应激水平高于白人，这可能是非裔美国人罹患癌症的几率较高的原因之一。其具体目的是1)确定饮食估计和血液中抗氧化营养素(总胡萝卜素、β-胡萝卜素、番茄红素、维生素C和维生素E)和氧化应激(外周淋巴细胞中的氧化DNA损伤)水平是否在健康的非裔美国人和白人之间存在差异，2)按种族检查抗氧化营养状态和氧化DNA损伤之间的关系，以及3)通过与4天食物记录和营养生物标记物进行比较，开发和测试新的抗氧化营养问卷的相对有效性，并检查有效性在非裔美国人和白人之间是否有所不同。为了实现这些目标，我们将从北卡罗来纳州的研究三角地区招募150名健康(即癌症和其他无慢性病)男性和女性成年人(75名非裔美国人和75名白人)，年龄在20-45岁之间。所有参与者将完成新的抗氧化营养问卷、人口统计和健康调查问卷、为期4天的食物记录，并采集血液样本，以使用单细胞凝胶电泳法或碱性彗星试验评估抗氧化营养素(胡萝卜素、维生素C和维生素E水平)和氧化DNA损伤。该项目填补了抗氧化剂和癌症研究的一个重要空白，通过在混合种族样本中提供关于抗氧化剂营养物质和氧化应激之间的生物学关系的重要信息，并应用于癌症风险研究。此外，这项工作可能会为研究人员提供一种有效的工具，用于评估美国人群研究中的抗氧化剂营养暴露。

DESCRIPTION (provided by applicant): Cancer is the second leading cause of death in the United States (U.S.), with higher incidence and mortality rates for African Americans than other racial or ethnic groups. Studies suggest that oxidative stress may be causally related to the incidence of many chronic diseases, such as cancer, and that antioxidant nutritional status is inversely related to the occurrence of various cancers. However, there is limited information about possible racial differences in associations between antioxidant nutrients and oxidative stress in healthy persons, and there is a need for improved methodologies to accurately assess self-reported antioxidant nutrient intakes in population-based epidemiologic studies. The hypothesis of this project is that African Americans have lower blood levels of antioxidant nutrients and higher levels of oxidative stress than Whites, which may be one reason why African Americans have higher rates of cancer. The specific aims are to 1) determine whether dietary estimates and blood levels of antioxidant nutrients (total carotenoids, beta-carotene, lycopene, vitamin C, and vitamin E) and oxidative stress (measured as oxidative DNA damage in peripheral lymphocytes) differ between healthy African Americans and Whites, 2) examine associations between antioxidant nutrient status and oxidative DNA damage, by race, and 3) develop and test the relative validity era new antioxidant nutrient questionnaire by comparison to 4-day food records and nutrient biomarkers, and examine whether the validity differs between African Americans and Whites. To accomplish these aims, we will recruit a sample of 150 healthy (i.e., cancer and other chronic disease-free) male and female adults (75 African American and 75 White), age 20-45 years, from the Research Triangle Area of North Carolina. All participants will complete the new antioxidant nutrient questionnaire, a demographic and health questionnaire, a 4-day food record, and have blood samples collected for evaluation of antioxidant nutrients (carotenoids, vitamin C, and vitamin E levels) and oxidative DNA damage using the single cell gel electrophoresis or alkaline Comet assay. This project fills an important gap in antioxidant and cancer research by providing important information about biological relationships between antioxidant nutrients and oxidative stress in a mixed-race sample, with applications to cancer risk. In addition, this work would potentially provide investigators with a validated instrument for assessing antioxidant nutrient exposure in population-based studies in the U.S.