Stolzenberg-Solomon Rachael Z, Chang Shih-Chen, Leitzmann Michael F, Johnson Karen A, Johnson Christine, Buys Saundra S, Hoover Robert N, Ziegler Regina G
Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, 6120 Executive Boulevard, Suite 320, Rockville, MD 20852, USA.
Am J Clin Nutr. 2006 Apr;83(4):895-904. doi: 10.1093/ajcn/83.4.895.
Several epidemiologic studies suggest that higher folate intakes are associated with lower breast cancer risk, particularly in women with moderate alcohol consumption.
We investigated the association between dietary folate, alcohol consumption, and postmenopausal breast cancer in women from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial cohort.
Dietary data were collected at study enrollment between 1993 and 2001. Folate content was assigned on the basis of prefortification (ie, pre-1998) databases. Of the 25 400 women participants with a baseline age of 55-74 y and with complete dietary and multivitamin information, 691 developed breast cancer between September 1993 and May 2003. We used Cox proportional hazard models with age as the underlying time metric to generate hazard ratios (HRs) and 95% CIs.
The adjusted HRs were 1.19 (95% CI: 1.01, 1.41; P for trend = 0.04) for women reporting supplemental folic acid intake >/=400 mug/d compared with subjects reporting no supplemental intake. Comparison of the highest with the lowest quintile gave adjusted HRs of 1.04 (95% CI: 0.83, 1.31; P for trend = 0.56) and 1.32 (95% CI: 1.04, 1.68; P for trend = 0.03) for food and total folate intake, respectively. Alcohol consumption was positively associated with breast cancer risk (highest compared with lowest quintile: HR = 1.37; 95% CI: 1.08, 1.76; P for trend = 0.02); the risk was greatest in women with lower total folate intake.
Our results do not support the hypothesis that high folate intake reduces breast cancer risk; instead, they suggest that a high intake, generally attributable to supplemental folic acid, may increase the risk in postmenopausal women. However, our results confirm previous studies showing positive associations between moderate alcohol consumption and breast cancer.
多项流行病学研究表明，较高的叶酸摄入量与较低的乳腺癌风险相关，尤其是在适度饮酒的女性中。
我们在前列腺、肺癌、结直肠癌和卵巢癌筛查试验队列的女性中，研究膳食叶酸、饮酒与绝经后乳腺癌之间的关联。
在1993年至2001年研究入组时收集膳食数据。叶酸含量根据强化前（即1998年前）的数据库进行赋值。在25400名基线年龄为55 - 74岁且有完整膳食和多种维生素信息的女性参与者中，691人在1993年9月至2003年5月期间患乳腺癌。我们使用以年龄为基本时间指标的Cox比例风险模型来生成风险比（HR）和95%置信区间（CI）。
与未报告补充叶酸摄入的受试者相比，报告补充叶酸摄入量≥400微克/天的女性调整后的HR为1.19（95%CI：1.01，1.41；趋势P值 = 0.04）。食物叶酸摄入量和总叶酸摄入量最高五分位数与最低五分位数相比，调整后的HR分别为1.04（95%CI：0.83，1.31；趋势P值 = 0.56）和1.32（95%CI：1.04，1.68；趋势P值 = 0.03）。饮酒与乳腺癌风险呈正相关（最高五分位数与最低五分位数相比：HR = 1.37；95%CI：1.08，1.76；趋势P值 = 0.02）；在总叶酸摄入量较低的女性中风险最大。
我们的结果不支持高叶酸摄入量会降低乳腺癌风险这一假设；相反，结果表明高摄入量（通常归因于补充叶酸）可能会增加绝经后女性的风险。然而，我们的结果证实了先前的研究，即适度饮酒与乳腺癌之间存在正相关。
