Long-term effects of guar gum in subjects with non-insulin-dependent diabetes mellitus.

The effects of 15 g guar gum/d on glycemic control, lipids, and insulin secretion were studied in 15 (8 male, 7 female) diet-treated subjects with non-insulin-dependent diabetes mellitus for 48 wk. Mean age (+/- SD) was 60 +/- 2 y (range 45-70 y), body mass index (in kg/m2) 28.6 +/- 0.9 (range 21.6 +/- 39.2), and duration of diabetes 6 +/- 1 y (range 2-14 y). Guar gum was preceded and followed by 8-wk placebo periods. Guar gum improved long-term glycemic control, postprandial glucose tolerance and lipid concentrations. The C-peptide response to a test meal increased by time during guar gum treatment, whereas the insulin response remained unchanged. This indicates that insulin secretion is enhanced by guar gum as reflected by increased C-peptide. A decreased molar ratio of insulin to C-peptide suggests that guar gum may increase hepatic insulin extraction. In conclusion, guar gum has favorable long-term effects on glycemic control and lipid concentrations.