Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
Department of Clinical Nutrition and Dietetics, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Clin Nutr. 2019 Dec;38(6):2690-2695. doi: 10.1016/j.clnu.2018.11.023. Epub 2018 Nov 30.
Observational studies that investigated the association between adherence to low carbohydrate diet and odds of glioma are sparse. This is particularly relevant in developing countries where dietary carbohydrate intake is very high.
This study was, therefore, conducted to investigate the association between adherence to low carbohydrate dietary pattern and odds of glioma among Iranian adults.
In this hospital-based case-control study, 128 newly diagnosed glioma cases were recruited and 256 age- and sex-matched subjects were enrolled as controls. Dietary intakes were examined by the use of a 126-item validated FFQ. Low carbohydrate diet (LCD) score was computed for each participant based on deciles of percentages of energy from carbohydrates, proteins, and fats. Individuals in the lowest decile of carbohydrate consumption received 10 points. Participants in second decile received 9 points and so on down to participants in the highest decile received 1 points. For fat and protein intakes, the points assigned to deciles were reversed; such that those in the highest decile received 10 points and those in the lowest decile received 1 point. We then summed all points of the three macronutrients to achieve the overall diet score, which ranged from 3 (highest carbohydrate intake and lowest fat and protein intakes) to 30 (lowest carbohydrate intake and highest fat and protein intakes). The higher the score, the greater adherence to the LCD dietary pattern.
After adjustment for age and sex, we found that individuals in top tertile of LCD score were 60% less likely to have glioma compared with those in the bottom tertile (OR: 0.40; 95% CI: 0.23, 0.67). Additional controlling for other potential confounders made the association slightly attenuated (OR: 0.49; 95%CI: 0.26, 0.93). Further adjustment for dietary nutrient intakes strengthened the association (OR: 0.32; 95%CI: 0.12, 0.81). After additional controlling for BMI, we found that adherence to LCD was protectively associated with reduced odds of glioma (OR: 0.32; 95%CI: 0.12, 0.81).
We found an inverse association between adherence to LCD and odds of glioma among Iranian population. Prospective cohort studies are needed to confirm these findings.
针对低碳水化合物饮食与神经胶质瘤发病风险之间关联的观察性研究较为匮乏。而在碳水化合物摄入量非常高的发展中国家，这一问题显得尤为重要。
因此，本研究旨在调查伊朗成年人中低碳水化合物饮食模式与神经胶质瘤发病风险之间的关联。
本病例对照研究以医院为基础，共纳入 128 例新诊断的神经胶质瘤患者作为病例组，256 例年龄和性别匹配的受试者作为对照组。采用经过验证的 126 项食物频数问卷评估膳食摄入量。根据碳水化合物、蛋白质和脂肪能量百分比的十分位数，为每位参与者计算低碳水化合物饮食（LCD）评分。碳水化合物摄入量最低的十分位数得 10 分，第二十分位数得 9 分，以此类推，最高十分位数得 1 分。对于脂肪和蛋白质摄入量，分配给十分位数的分数相反；即最高十分位数得 10 分，最低十分位数得 1 分。然后将三种宏量营养素的所有分数相加，得到总分，范围为 3（碳水化合物摄入量最高，脂肪和蛋白质摄入量最低）至 30（碳水化合物摄入量最低，脂肪和蛋白质摄入量最高）。分数越高，对 LCD 饮食模式的依从性越高。
在调整年龄和性别后，我们发现，与最低三分位相比，LCD 评分最高三分位的个体患神经胶质瘤的风险降低了 60%（OR：0.40；95%CI：0.23，0.67）。进一步控制其他潜在混杂因素后，该关联略有减弱（OR：0.49；95%CI：0.26，0.93）。进一步调整膳食营养素摄入量后，该关联得到了加强（OR：0.32；95%CI：0.12，0.81）。在进一步控制 BMI 后，我们发现，对 LCD 的依从性与降低神经胶质瘤的发病风险呈保护相关（OR：0.32；95%CI：0.12，0.81）。
我们在伊朗人群中发现了 LCD 依从性与神经胶质瘤发病风险之间的反比关联。需要前瞻性队列研究来证实这些发现。
