Spiller G A
Health Research and Studies Center, Inc, Los Altos, CA 94023-0338.
Am J Clin Nutr. 1991 Oct;54(4):615-7. doi: 10.1093/ajcn/54.4.615.
The complexity of plant foods high in dietary fiber poses new challenges to clinical investigators and leads to many study-design dilemmas. There are basic differences in studying purified polymers, highly concentrated but not purified fibers, and diets high in high-fiber whole foods. The fibrils of the plant cell wall are most likely altered when prepared as a pure chemical entity, and when fiber concentrates (eg, wheat bran) are used, the method of preparation may alter the composition of the final product. Whole-plant, high-fiber foods are complex storehouses of a diversity of polymers, including resistant starch, and of bioactive compounds. Furthermore, the addition of a reasonable amount of high-fiber food to the diet not only adds dietary fiber but many digestible, caloric macronutrients that alter the entire diet composition. These problems and dilemmas are reviewed.
富含膳食纤维的植物性食物的复杂性给临床研究人员带来了新的挑战，并导致了许多研究设计上的困境。研究纯化的聚合物、高浓度但未纯化的纤维以及富含高纤维全食物的饮食存在根本差异。当作为纯化学实体制备时，植物细胞壁的原纤维很可能会发生改变，而当使用纤维浓缩物（如麦麸）时，制备方法可能会改变最终产品的成分。全植物性高纤维食物是多种聚合物（包括抗性淀粉）和生物活性化合物的复杂储存库。此外，在饮食中添加适量的高纤维食物不仅会增加膳食纤维，还会增加许多可消化的、提供热量的大量营养素，从而改变整个饮食组成。本文对这些问题和困境进行了综述。
