Wedlake Linda, Shaw Clare, McNair Helen, Lalji Amyn, Mohammed Kabir, Klopper Tanya, Allan Lindsey, Tait Diana, Hawkins Maria, Somaiah Navita, Lalondrelle Susan, Taylor Alexandra, VanAs Nicholas, Stewart Alexandra, Essapen Sharadah, Gage Heather, Whelan Kevin, Andreyev H Jervoise N
Departments of Nutrition and Dietetics.
Radiotherapy.
Am J Clin Nutr. 2017 Sep;106(3):849-857. doi: 10.3945/ajcn.116.150565. Epub 2017 Jul 5.
Therapeutic radiotherapy is an important treatment of pelvic cancers. Historically, low-fiber diets have been recommended despite a lack of evidence and potentially beneficial mechanisms of fiber. This randomized controlled trial compared low-, habitual-, and high-fiber diets for the prevention of gastrointestinal toxicity in patients undergoing pelvic radiotherapy. Patients were randomly assigned to low-fiber [≤10 g nonstarch polysaccharide (NSP)/d], habitual-fiber (control), or high-fiber (≥18 g NSP/d) diets and received individualized counseling at the start of radiotherapy to achieve these targets. The primary endpoint was the difference between groups in the change in the Inflammatory Bowel Disease Questionnaire-Bowel Subset (IBDQ-B) score between the starting and nadir (worst) score during treatment. Other measures included macronutrient intake, stool diaries, and fecal short-chain fatty acid concentrations. Patients were randomly assigned to low-fiber ( = 55), habitual-fiber ( = 55), or high-fiber ( = 56) dietary advice. Fiber intakes were significantly different between groups ( < 0.001). The difference between groups in the change in IBDQ-B scores between the start and nadir was not significant ( = 0.093). However, the change in score between the start and end of radiotherapy was smaller in the high-fiber group (mean ± SD: -3.7 ± 12.8) than in the habitual-fiber group (-10.8 ± 13.5; = 0.011). At 1-y postradiotherapy ( = 126) the difference in IBDQ-B scores between the high-fiber (+0.1 ± 14.5) and the habitual-fiber (-8.4 ± 13.3) groups was significant ( = 0.004). No significant differences were observed in stool frequency or form or in short-chain fatty acid concentrations. Significant reductions in energy, protein, and fat intake occurred in the low- and habitual-fiber groups only. Dietary advice to follow a high-fiber diet during pelvic radiotherapy resulted in reduced gastrointestinal toxicity both acutely and at 1 y compared with habitual-fiber intake. Restrictive, non-evidence-based advice to reduce fiber intake in this setting should be abandoned. This trial was registered at clinicaltrials.gov as NCT 01170299.
放射治疗是盆腔癌的一种重要治疗方法。从历史上看，尽管缺乏证据且不清楚纤维的潜在有益机制，但仍推荐低纤维饮食。这项随机对照试验比较了低纤维、常规纤维和高纤维饮食对接受盆腔放疗患者预防胃肠道毒性的效果。患者被随机分配到低纤维饮食组（≤10克非淀粉多糖[NSP]/天）、常规纤维饮食组（对照组）或高纤维饮食组（≥18克NSP/天），并在放疗开始时接受个性化咨询以达到这些目标。主要终点是治疗开始至最低点（最差）期间炎症性肠病问卷-肠道子集（IBDQ-B）评分变化的组间差异。其他测量指标包括常量营养素摄入量、大便日记和粪便短链脂肪酸浓度。患者被随机分配接受低纤维饮食建议（n = 55）、常规纤维饮食建议（n = 55）或高纤维饮食建议（n = 56）。各组之间的纤维摄入量有显著差异（P < 0.001）。治疗开始至最低点期间IBDQ-B评分变化的组间差异不显著（P = 0.093）。然而，高纤维组放疗开始至结束时的评分变化（平均值±标准差：-3.7±12.8）小于常规纤维组（-10.8±13.5；P = 0.011）。放疗后1年（n = 126），高纤维组（+0.1±14.5）和常规纤维组（-8.4±13.3）的IBDQ-B评分差异显著（P = 0.004）。在大便频率或形态以及短链脂肪酸浓度方面未观察到显著差异。仅低纤维组和常规纤维组的能量、蛋白质和脂肪摄入量显著减少。与常规纤维摄入量相比，盆腔放疗期间遵循高纤维饮食的建议在急性期和1年时均能降低胃肠道毒性。在这种情况下，减少纤维摄入的限制性、无证据支持的建议应被摒弃。该试验在clinicaltrials.gov上注册为NCT 01170299。
