Background Evidence is accumulating that high dietary glycaemic index (GI) and glycaemic load (GL) are potential risk factors for several metabolic disorders (e.g. type-2 diabetes, cardiovascular diseases), but remains limited concerning cancer risk. Although, mechanistic data suggest that consuming high-GI foods may contribute to carcinogenesis through elevated blood glucose levels, insulin resistance or obesity-related mechanisms. Our objective was to study the associations between dietary GI/GL and cancer. Methods In total, 103 020 French adults (median age = 40.2 years) from the NutriNet-Santé cohort (2009–2020) with no cancer or diabetes at baseline were included (705 137 person-years, median follow-up time = 7.7 years). Repeated 24-h dietary records linked with a detailed food-composition table (>3500 food/beverage items). We computed the average dietary GI and GL at the individual level. Associations between GI, GL, contribution of low- and medium/high-GI foods to energy and carbohydrate intake and cancer risk (overall, breast, prostate and colorectal) were assessed using multivariable Cox proportional-hazard models. Results Higher dietary GL was associated with higher overall cancer risk [n = 3131 cases, hazard ratios (HRs) for sex-specific quintile 5 vs 1 = 1.25, 95% confidence interval (CI) = 1.03–1.52; Ptrend = 0.008] and specifically postmenopausal breast cancer (n = 924, HRQ5vs.Q1 = 1.64, 95% CI = 1.06–2.55; Ptrend = 0.03). A higher contribution of low-GI food/beverages to energy intake was associated with lower cancer risk whereas a higher contribution of medium/high-GI items to energy intake was positively associated with higher risk of overall, breast and postmenopausal breast cancers (Ptrend ≤ 0.02). Conclusions These results support a possible impact of GI/GL on cancer risk. If confirmed in other populations and settings, dietary GI/GL could be considered as modifiable risk factors for primary cancer prevention. Trial registration https://clinicaltrials.gov/ct2/show/NCT03335644.

中文翻译：

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血糖指数、血糖负荷和癌症风险：来自前瞻性 NutriNet-Santé 队列的结果

背景 越来越多的证据表明，高膳食血糖指数 (GI) 和血糖负荷 (GL) 是几种代谢紊乱（例如 2 型糖尿病、心血管疾病）的潜在危险因素，但在癌症风险方面仍然有限。虽然，机​​制数据表明，食用高 GI 食物可能通过升高的血糖水平、胰岛素抵抗或肥胖相关机制导致致癌。我们的目标是研究膳食 GI/GL 与癌症之间的关联。方法 总共包括来自 NutriNet-Santé 队列（2009-2020 年）的 103020 名法国成年人（中位年龄 = 40.2 岁），基线时没有癌症或糖尿病（705137 人年，中位随访时间 = 7.7 年） ）。重复的 24 小时饮食记录与详细的食物成分表（>3500 种食物/饮料）相关联。我们计算了个体水平的平均膳食 GI 和 GL。使用多变量 Cox 比例风险模型评估了 GI、GL、低和中/高 GI 食物对能量和碳水化合物摄入的贡献以及癌症风险（总体、乳腺癌、前列腺癌和结肠直肠癌）之间的关联。结果 较高的饮食 GL 与较高的总体癌症风险相关 [n = 3131 例，性别特异性五分位数 5 与 1 的风险比 (HR) = 1.25，95% 置信区间 (CI) = 1.03–1.52；Ptrend = 0.008]，特别是绝经后乳腺癌（n = 924，HRQ5vs.Q1 = 1.64，95% CI = 1.06–2.55；Ptrend = 0.03）。低GI食物/饮料对能量摄入的较高贡献与较低的癌症风险相关，而中/高GI食物对能量摄入的较高贡献与较高的总体风险呈正相关，乳腺癌和绝经后乳腺癌（Ptrend ≤ 0.02）。结论 这些结果支持 GI/GL 对癌症风险的可能影响。如果在其他人群和环境中得到证实，饮食 GI/GL 可被视为初级癌症预防的可改变风险因素。试验注册 https://clinicaltrials.gov/ct2/show/NCT03335644。