Abstract

     Rice is a major staple food in Asian countries and it is a rich source of carbohydrate. Since Glycemic Index (GI), Glycemic Load (GL) and Insulinemic Index (II) (three important measures of clinical concern in the management and prevention of diabetes and metabolic syndrome) vary from population to population, we have measured these parameters in healthy Bangladeshi subjects with 3 commonly consumed rice (BR-14, BR-29 and BR-44). Participants consisted of ten healthy subjects (male 5, female 5, age 28.6 years, BMI 22.5) were studied under a cross-over design. The test meals contained 50 g of total carbohydrate and were given to the participants for ingestion within 10 min with 200 ml water. Serum levels of glucose were estimated at 0, 30, 60, 90 and 120 min respectively. Serum glucose was measured by glucose-oxidase and C-peptide was used as the marker of insulin and was measured by chemiluminescent ELISA method. Classification of GI was taken from the international table (GI: High ≥ 70, Medium 56 - 69 and low ≤ 55; GL: High ≥ 20, Medium 11 - 19 and low ≤ 10). All the varieties of rice showed significantly lower serum glucose response compared to that of the reference food (that is, Glucose) [iAUC (M ± SD): 316.4 ± 151.6 in Glucose vs 154.8 ± 51.8 in BR-14, 155.6 ± 78.3 in BR-29 and 109.4 ± 59.3 in BR-44; p < 0.05 and 0.015 respectively]. The GI of BR-14, BR-29 and BR-44 were 54.5 ± 16.1, 50.3 ± 19.3 and 43.1 ± 38.4 respectively. The basal values of serum c-peptide among the 4 groups did not differ with each other. The postprandial serum c-peptide value of BR-14, BR-29 and BR-44 were significantly lower at all time points [120 min; (4.3 ± 1.4), (4.3 ± 1.0) and (4.2 ± 1.3); p < 0.015 and 0.001 respectively] compared to the reference food (6.2 ± 1.1).The GL of BR-14, BR-29 and BR-44 were 25, 22 and 20 respectively. Bangladeshi BR-14, BR-29 and BR-44 rice varieties have low GI. This property is not due to their insulin secretion and their content of dietary fibers, but it may relate to their amylase contents. Higher serving size, however, may turn these varieties into high GL rice and health providers should make people aware of this fact.  

Key words: Glycemic index, glycemic load, BR-14, BR-29, BR-44, Bangladesh, obesity, type II diabetes.