Diet plays a central role in the management of type 2 diabetes mellitus (T2DM). Diet contains a multitude of nutritional and chemical molecules each capable of regulating a number of biological processes. One of the nutrients, which is of prime importance, is the quantity and quality of carbohydrates (CHO). The diabetics are advised to select carbohydrate foods that minimize the postprandial blood glucose excursions, which on a long run would help to prevent the development of secondary complications. This has led to the introduction of GI where the effects of various CHO-containing foods on postprandial plasma glucose concentrations are classified in relation to the response elicited by an index glucose challenge. The concept of GI of foods was first introduced by Jenkins et al.2 and is defined as the ratio between area under the 2 h postprandial glycemic curve on ingestion of carbohydrate (test food) and on ingestion of glucose.
Area under 2-h blood glucose curve on ingestion of test food
Area under 2-h blood glucose curve on ingestion of standard glucose
The way the gastrointestinal tract handles the CHO is modulated by a number of food factors present in the food, as a result different equicarbohydrate foods produce different glycemic responses. There are several factors affecting the GI of a food. These include:
• Nature of starch and its digestibility
• Method of cooking and processing
• Physical characteristics of food/starches
• Protein and fat content
• Fiber content of food
The factors affecting GI along with their postulated mechanisms are summarized below:
Factors affecting GI
Nutrient-starch interaction Antinutrients
Method of cooking and processing
Protein and fat content Fiber
Amylopectin—larger surface area per molecule than amylose, therefore, easy enzymatic attack
Starch protein complex: unavailable for enzymatic attack
Binds with nutrients or enzymes and delays digestion process
Starch becomes more soluble, therefore, easy enzymatic digestion
Protein stimulates insulin secretion, fat delays gastric emptying
Delays gastric emptying and gel formation
The clinical utility of GI lies in classifying foods into low-, moderate-, and high-GI foods, which would help in developing appropriate exchange lists for diabetics. Apart from this, the therapeutic implications of low-GI foods have been documented in literature and are as follows:
• Helps to control established diabetes
• Helps to lose weight
• Improves the insulin sensitivity
• Reduces appetite for quick sugars and carbohydrates, thus avoiding blood sugar spikes
• Can help to minimize the hypoglycemic effect of sudden intensive exercise
Over the years, several researchers across the globe have carried out research pertaining to GI and its implications in health and disease.2-7 Similarly, in the Indian context, research related to low-GI foods and their therapeutic importance has also been studied extensively. The GI of traditional Indian CHO foods, conventional CHO meals, cereal pulse mix, combination of cereals and green leafy vegetables, and regional Indian meals have been carried out.8-12 In this context, Spirulina, which has bio-active compounds that enhance health, was incorporated into various recipes and tested for their glycemic and lipemic responses, the results of which are discussed below.
Glycemic and Lipemic Responses of Sp/Vu//na-Supplemented Rice-Based Preparations
Recipes tested: Rice alone, Rice with green gram dal, Rice with red gram dal, Rice with peas, Vegetable pulao with curd Subjects: Normal subjects Carbohydrate load: 50 g
Level of Spirulina supplementation: 2.5 g spray-dried powder Number of subjects: Six for each recipe
The nutritive value of rice-based recipes incorporated with Spirulina is depicted in Table 3.5.
The GI of the various recipes ranged from 38% to 50%. Rice alone elicited a higher GI in comparison to rice preparations with a combination of pulses and vegetables. Similarly, on comparing the glycemic response of the Spirulina-supplemented recipes with that of unsupplemented recipes carried out on T2DM, a marked reduction in GI was noticed. A similar trend was observed with respect to the lipemic response (Table 3.5).
Was this article helpful?