Center for Medical Biomics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
J Nutr. 2012 Feb;142(2):258-63. doi: 10.3945/jn.111.147884. Epub 2012 Jan 5.
Starchy food products differ in the rate of starch digestion, which can affect their metabolic impact. In this study, we examined how the in vivo starch digestibility is reflected by the glycemic response, because this response is often used to predict starch digestibility. Ten healthy male volunteers [age 21 ± 0.5 y, BMI 23 ± 0.6 kg/m² (mean ± SEM)] participated in a cross-over study, receiving three different meals: pasta with normal wheat bran (PA) and bread with normal (CB) or purple wheat bran (PBB). Purple wheat bran was added in an attempt to decrease the rate of starch digestion. The meals were enriched in ¹³C and the dual isotope technique was applied to calculate the rate of appearance of exogenous glucose (RaE). The ¹³C-isotopic enrichment of glucose in plasma was measured with GC/combustion/isotope ratio MS (IRMS) and liquid chromatography/IRMS. Both IRMS techniques gave similar results. Plasma glucose concentrations [2-h incremental AUC (iAUC)] did not differ between the test meals. The RaE was similar after consumption of CB and PBB, showing that purple wheat bran in bread does not affect in vivo starch digestibility. However, the iAUC of RaE after men consumed PA was less than after they consumed CB (P < 0.0001) despite the similar glucose response. To conclude, the glycemic response does not always reflect the in vivo starch digestibility. This could have implications for intervention studies in which the glycemic response is used to characterize test products.
淀粉类食物的淀粉消化率不同，这会影响它们的代谢影响。在这项研究中，我们研究了体内淀粉消化率如何反映血糖反应，因为血糖反应通常用于预测淀粉消化率。10 名健康男性志愿者[年龄 21 ± 0.5 岁，BMI 23 ± 0.6 kg/m²（平均值 ± SEM）]参加了一项交叉研究，分别接受三种不同的餐食：普通小麦麸皮意大利面（PA）和普通（CB）或紫麦麸面包（PBB）。添加紫麦麸是为了降低淀粉消化率。这些餐食富含¹³C，应用双同位素技术计算外源性葡萄糖的出现率（RaE）。用 GC/燃烧/同位素比 MS（IRMS）和液相色谱/IRMS 测量血浆中葡萄糖的¹³C 同位素丰度。两种 IRMS 技术都给出了相似的结果。测试餐之间的血浆葡萄糖浓度[2 小时增量 AUC（iAUC）]没有差异。CB 和 PBB 餐后 RaE 相似，表明面包中的紫麦麸不影响体内淀粉消化率。然而，男性食用 PA 后 RaE 的 iAUC 低于食用 CB 后（P < 0.0001），尽管血糖反应相似。总之，血糖反应并不总是反映体内淀粉消化率。这可能对以血糖反应来描述测试产品的干预研究产生影响。
