Vahid Farhad, Rahmani Diana, Davoodi Seyed Hossein
Department of Nutritional Sciences, Arak University of Medical Science, Arāk, Iran.
Department of Nutritional Sciences, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Nutr Metab (Lond). 2020 Dec 1;17(1):102. doi: 10.1186/s12986-020-00529-w.
Gastric cancer (GC) incidence and mortality are rapidly growing worldwide. It is estimated that more than 1,000,000 new cases are diagnosed each year, and more than 78,000 people lose their lives due to GC. The association between dietary antioxidants and GC has been shown in some studies. However, because of the discrepancy between the findings and the lack of a valid indicator, it seems necessary to design and validate the Dietary Antioxidant Index (DAI) to examine the diet's total antioxidant content. The present study aimed to survey the validity of DAI and its association with the odds of GC.
In this hospital-based case-control study, 82 patients with GC and 95 healthy controls were examined. We used a 168-item food frequency questioner to assess dietary intakes. The DAI was calculated based on the intake of vitamin A, C, E, and selenium, manganese, and zinc. We standardized each of the six vitamins and minerals by subtracting the global mean and dividing by the global standard deviation to calculate DAI. We then calculated the DAI by summing up the standardized intakes of these vitamins and minerals of the individuals with equal weight.
We observed a significant correlation between DAI and total antioxidant capacity (TAC) after controlling for age, body mass index (BMI), energy intake, smoking and fasting blood sugar, education, total fat intake, helicobacter pylori infection, total cholesterol, and saturated fatty acid (SFA) intakes. Results obtained from modeling DAI as a continuous variable in relation to GC showed a negative association after adjustment for age and in the multivariable analysis (OR = 0.64, CI = 0.43-0.95).
DAI is a valid indicator of dietary antioxidants assessments, and it can be used as a predictor of antioxidant status due to its correlation with serum antioxidant levels. The results showed that dietary antioxidants have a significant relationship with GC, which indicates the importance of antioxidants in this cancer's etiology.
全球范围内，胃癌（GC）的发病率和死亡率正在迅速上升。据估计，每年有超过100万新病例被诊断出来，超过7.8万人因胃癌丧生。一些研究已经表明饮食中的抗氧化剂与胃癌之间存在关联。然而，由于研究结果存在差异且缺乏有效的指标，似乎有必要设计并验证饮食抗氧化指数（DAI），以检测饮食中的总抗氧化剂含量。本研究旨在调查DAI的有效性及其与胃癌发病几率的关联。
在这项基于医院的病例对照研究中，对82例胃癌患者和95名健康对照者进行了检查。我们使用了一份包含168个条目的食物频率问卷来评估饮食摄入量。DAI是根据维生素A、C、E以及硒、锰和锌的摄入量计算得出的。我们通过减去全球均值并除以全球标准差，对这六种维生素和矿物质中的每一种进行标准化，以计算DAI。然后，我们通过将这些个体等权重的维生素和矿物质的标准化摄入量相加来计算DAI。
在控制了年龄、体重指数（BMI）、能量摄入、吸烟、空腹血糖、教育程度、总脂肪摄入、幽门螺杆菌感染、总胆固醇和饱和脂肪酸（SFA）摄入后，我们观察到DAI与总抗氧化能力（TAC）之间存在显著相关性。将DAI作为与胃癌相关的连续变量进行建模得到的结果显示，在调整年龄后以及在多变量分析中呈负相关（OR = 0.64，CI = 0.43 - 0.95）。
DAI是饮食抗氧化剂评估的有效指标，由于其与血清抗氧化水平相关，它可以用作抗氧化状态的预测指标。结果表明，饮食中的抗氧化剂与胃癌有显著关系，这表明抗氧化剂在这种癌症的病因学中具有重要意义。
