Kushi L H, Fee R M, Sellers T A, Zheng W, Folsom A R
Division of Epidemiology, University of Minnesota School of Public Health, Minneapolis 55454-1015, USA.
Am J Epidemiol. 1996 Jul 15;144(2):165-74. doi: 10.1093/oxfordjournals.aje.a008904.
The association between dietary antioxidant vitamin intake and the risk of breast cancer was examined in a prospective study of 34,387 postmenopausal women in Iowa. Intakes of vitamins A, C, and E and of retinol and carotenoids were assessed in 1986 by mailed semiquantitative food frequency questionnaire. Through December 31, 1992, 879 incident breast cancer cases occurred in this cohort. There was little suggestion that breast cancer risk was associated with differences in intake of these vitamins. For example, from the lowest to highest total vitamin A intake categorized by quintiles, the age-adjusted relative risks of breast cancer were 1.0, 0.95, 1.17, 1.20, and 0.90 (p trend = 0.92). Similarly unremarkable relative risk patterns were seen for the intakes of vitamins C and E and of retinol and carotenoids. These findings were not altered after adjustment for breast cancer risk factors or in analyses confined to women who reported no supplemental vitamin intake. Exclusion of cases that occurred in the first 2 years of follow-up, under the assumption that women may have increased intake of these vitamins in response to preclinical symptoms of breast cancer, did not suggest an inverse association of these vitamins with the risk of breast cancer. Women who reported consuming at least 500 mg/day of supplemental vitamin C had a relative risk of breast cancer of 0.79 compared with women who did not take supplemental vitamin C, and women who reported consuming more than 10,000 IU/day of vitamin A had a corresponding relative risk of 0.73. However, these relative risks were not statistically significant. These results provide little evidence that intake of these vitamins is associated with breast cancer risk.
在爱荷华州对34387名绝经后女性进行的一项前瞻性研究中，研究了膳食抗氧化剂维生素摄入量与患乳腺癌风险之间的关联。1986年通过邮寄半定量食物频率问卷评估了维生素A、C、E以及视黄醇和类胡萝卜素的摄入量。到1992年12月31日，该队列中出现了879例新发乳腺癌病例。几乎没有迹象表明乳腺癌风险与这些维生素摄入量的差异有关。例如，按五分位数分类，从维生素A总摄入量最低到最高，乳腺癌的年龄调整相对风险分别为1.0、0.95、1.17、1.20和0.90（p趋势=0.92）。维生素C、E以及视黄醇和类胡萝卜素的摄入量也呈现出同样不显著的相对风险模式。在对乳腺癌风险因素进行调整后，或者在仅限于报告未摄入补充维生素的女性的分析中，这些发现没有改变。假设女性可能因乳腺癌的临床前症状而增加这些维生素的摄入量，排除随访前两年发生的病例后，并未显示这些维生素与乳腺癌风险呈负相关。报告每天至少摄入500毫克补充维生素C的女性患乳腺癌的相对风险为0.79，而未摄入补充维生素C的女性为1；报告每天摄入超过10000国际单位维生素A的女性患乳腺癌的相应相对风险为0.73。然而，这些相对风险没有统计学意义。这些结果几乎没有提供证据表明这些维生素的摄入量与乳腺癌风险有关。
