Glycemic indices of three commonly consumed foods: a clinical trial in Iranian healthy adults

Abstract

Type of carbohydrate and glycemic index of traditional foods is still a challenge in nutritional management of diabetics. This study was conducted to determine the GI of pasta (ordinary and infused), made from either nol (common wheat) or semolina (durum wheat) flour, compared to white rice in subjects. Twelve healthy volunteers with body mass index 23.5 ± 1.45 kg/m² and age 36 ± 2.85 years participated in this study. Twelve hours overnight fasting capillary blood samples were collected from subjects at baseline by finger stick using a sterile lancet pen immediately before ingestion of either 50 g of d-glucose anhydrate dissolved in 300 ml distilled water, 192.3 g cooked pasta or 185.2 g of rice (50 g carbohydrate) alongside 300 ml water. Blood samples were collected again at 0, 15, 30, 45, 60, 90 and 120 min. All subjects consumed the test meals at 1-week interval. The standard glucose solution was administered at the first and fourth week of study. Blood samples were analysed using an Accu-Chek Aviva Blood Glucose Monitor. The area under the curve was calculated as the incremental area under the blood glucose response curve for each test in each individual. The GI values were determined according to FAO/WHO standard methods. This study indicated that the GI of ordinary pasta made from semolina {47} is significantly lower than nol flour pasta {68} or cooked rice {73}. There was a reverse, but non-significant, difference between the GI of semolina-infused pasta {63} versus nol-infused pasta {60}. Glycemic index for pasta (semolina and non-infused) was significantly less than that of nol wheat pasta, cooked rice and white bread. This study underscores the importance of consuming ordinary pasta made from semolina as part of a low GI diet for controlling blood glucose levels.