Guar sprinkled on food: effect on glycaemic control, plasma lipids and gut hormones in non-insulin dependent diabetic patients

The effects of guar granules sprinkled over food on carbohydrate and lipid metabolism were studied in a double-blind cross-over trial in 18 patients with non-insulin-dependent diabetes mellitus (mean±SEM age 61.3±2.5 years). Five-gram guar granules (Guarem®, Rybar Laboratories, Amersham, Bucks) were sprinkled over food at each main meal for 4 weeks, and during a 4-week placebo period (separated by a 2-week ‘wash-out’ period), 5 g wheat bran was taken in the same way. Diabetic treatment was not changed during the study. Mean fasting plasma glucose (FPG) concentration and glycosylated haemoglobin (HbA-1) concentration after treatment were significantly lower than after the placebo period (FPG 8.29±0.47 vs 8.78±0.53 mmol/l, p<0.05; HbA1: 8.70±0.39 vs 9.09±0.39%, p<0.05). There was a 50% reduction in the incremental area under the postprandial glycaemic curve when guar was eaten with a standardized test meal. Total plasma cholesterol decreased from 5.79±0.29 to 5.19±0.22 mmol/l (p<0.05) after the guar treatment period. Guar ingestion reduced postprandial insulin and enteroglucagon responses, the latter significantly so, but had no apparent effect on gastric inhibitory polypeptide, pancreatic glucagon, gastrin, and pancreatic polypeptide.