Yale School of Public Health, 60 College Street, P.O. Box 208034, New Haven, CT 06520-8034, USA.
Cancer Epidemiol Biomarkers Prev. 2010 Jul;19(7):1709-22. doi: 10.1158/1055-9965.EPI-10-0225. Epub 2010 Jun 22.
N-nitroso compounds (NOC) are found in processed meat and are formed endogenously from intake of nitrite and nitrate. Endogenous NOC formation is antagonized by nitrosation inhibitors in fruit and vegetables (e.g., vitamin C) and promoted by heme in red meat. It has been hypothesized that a diet resulting in high exposure to NOCs increases adult glioma risk.
Using proportional hazards models, we tested this hypothesis among 545,770 participants in the prospective NIH-AARP Diet and Health Study, which assessed dietary intake at baseline (1995-1996) with a comprehensive food frequency questionnaire, and at ages 12 to 13 years with an abbreviated food frequency questionnaire.
During follow-up through 2003, 585 participants were diagnosed with glioma. We found no significant trends in glioma risk for consumption of processed or red meat, nitrate, or vitamin C or E. We found significant positive trends for nitrite intake from plant sources (hazard ratio for quintile 5 versus quintile 1, 1.59; 95% confidence interval, 1.20-2.10; P for trend = 0.028) and, unexpectedly, for fruit and vegetable intake (hazard ratio, 1.42; 95% confidence interval, 1.08-1.86; P for trend = 0.0081). Examination of interactions between dietary intakes (e.g., nitrite and vitamin C) and a limited analysis of diet at ages 12 to 13 years provided no support for the NOC hypothesis.
Our results suggest that consumption of processed or red meat, nitrite, or nitrate does not increase adult glioma risk, and that consumption of fruit and vegetables, vitamin C, or vitamin E does not reduce risk.
Our results, in agreement with the only previous prospective analysis, cast doubt on the NOC hypothesis in relation to dietary intake and adult glioma risk.
N-亚硝基化合物（NOC）存在于加工肉类中，并且可从摄入的亚硝酸盐和硝酸盐内源性形成。水果和蔬菜中的亚硝化抑制剂（例如维生素 C）可拮抗内源性 NOC 的形成，而红肉中的血红素则可促进其形成。有人假设，导致 NOC 暴露水平较高的饮食会增加成人患神经胶质瘤的风险。
我们在 NIH-AARP 饮食与健康研究中对 545770 名参与者进行了前瞻性研究，该研究使用了综合性食物频率问卷在基线（1995-1996 年）评估了饮食摄入情况，并使用简化食物频率问卷在 12 至 13 岁时评估了饮食摄入情况。使用比例风险模型，我们检验了这一假说。
在 2003 年之前的随访期间，有 585 名参与者被诊断患有神经胶质瘤。我们发现食用加工肉或红肉、硝酸盐或维生素 C 或 E 与神经胶质瘤风险无明显趋势。我们发现，植物来源的亚硝酸盐摄入量呈显著正相关趋势（五分位 5 与五分位 1 相比，危险比为 1.59；95%置信区间为 1.20-2.10；趋势 P 值=0.028），并且出乎意料的是，水果和蔬菜的摄入量也呈显著正相关（危险比为 1.42；95%置信区间为 1.08-1.86；趋势 P 值=0.0081）。对饮食摄入（例如亚硝酸盐和维生素 C）之间的相互作用进行的检查以及对 12 至 13 岁时饮食的有限分析并未支持 NOC 假说。
我们的结果表明，食用加工肉或红肉、亚硝酸盐或硝酸盐不会增加成人神经胶质瘤的风险，而食用水果、蔬菜、维生素 C 或维生素 E 也不会降低风险。
我们的结果与唯一的先前前瞻性分析一致，对 NOC 假说与饮食摄入和成人神经胶质瘤风险之间的关系提出了质疑。
