Mal J Nutr 24(3): 455-466, 2018 Finger millet (Eleusine coracana L.) and white rice diets elicit similar glycaemic response in Asian Indians: Evidence from a randomised clinical trial using continuous glucose monitoring Shanmugam Shobana1*, Rajagopal Gayathri1, Chandrasekaran Anitha1, Vasudevan Kavitha1, Nagamuthu Gayathri1, Mookambika Ramya Bai1, Nagarajan Lakshmipriya1, Muthukaruppan Malavika1, Vasudevan Sudha1, Ranjit Unnikrishnan2, Ranjit Mohan Anjana2, NG Malleshi1, Kamala Krishnaswamy1, CJK Henry 3 & Viswanathan Mohan1 1Department of Foods Nutrition & Dietetics Research, Madras Diabetes Research Foundation, Chennai, Tamil Nadu, India; 2Department of Diabetology, Madras Diabetes Research Foundation, Chennai, Tamil Nadu, India; 3Clinical Nutritional Sciences, Singapore Institute for Clinical Sciences, Brenner Centre for Molecular Medicine, Medical Drive, Singapore ABSTRACT Introduction: Finger millet (FM) or Eleusine coracana L. is considered as a healthier cereal option, especially based on its higher dietary fibre, phytochemical and mineral contents. FM is also recommended for individuals with diabetes, as it is believed to elicit a lower glycaemic response. Methods: The glycaemic response of FM diet was evaluated and compared with white rice (WR) diets using a continuous glucose monitoring system (CGMS™) iPro 2™ among 14 healthy male and female volunteers aged 25-45 years with normal Body Mass Index (≥22.9kg/m2) in a crossover trial. They were recruited from Madras Diabetes Research Foundation volunteers registry. The participants consumed randomised iso-caloric FM or WR based diets for five consecutive days and 24 h interstitial glucose concentrations were recorded. Results: The FM diet had significantly higher dietary fibre than WR (29.9 g vs 15.8 g/1000 kcal, p<0.01) but the other macronutrients were similar. The 5-day average incremental area under the curve (IAUC) of FM diet [Mean (95% CI) = 73.6 (62.1-85.1) mg*min/dl] was not significantly different from that for WR diet [Mean (95% CI) = 78.3(67.9-88.7) mg*min/dl]. Conclusion: Both finger millet and white rice diets showed similar 24 h glycaemic responses, despite the former having higher amounts of dietary fibre. The result suggests that use of FM flour-based food preparations and decorticated FM grains to replace WR in the Indian diets offer no significant benefit with regards to 24 h glycaemic response. Studies of longer duration with larger sample size are needed to verify our findings. Keywords: Finger millet, white rice, dietary intervention, dietary fibre, diabetes __________________________ *Corresponding author: Dr. S. Shobana, M. Sc., Ph. D (Biochem), PGDDE (Diabetes Education), PGDFT (Food Sci & Tech) Department of Foods, Nutrition, Dietetics Research, Madras Diabetes Research Foundation (MDRF) Kallam Anji Reddy Centre, Plot No. 20, Golden Jubilee Bio tech Park for Women Society, Sipcot - IT Park, Siruseri - 603103. Chennai Tel: 91-44-33505555; Fax: (9144) 2835 0935; E-mail: [email protected] 456 Shanmugam S, Rajagopal G, Chandrasekaran A et al. INTRODUCTION recommended as a healthier replacement to refined grain staples for individuals The prevalence of diabetes and obesity with diabetes. are rising rapidly. Individuals of south Though FM contains higher levels Asian origin specifically Asian Indians of dietary fibre and phytochemicals are known to be highly susceptible to (Shobana et al., 2013), this grain diabetes (Anjana et al., 2015). Although remains less explored for its glycaemic genetic factors may influence this properties (Glycaemic index) using susceptibility, lifestyle factors; faulty standardised international GI testing diets (high in refined carbohydrates) protocol (Shobana et al., 2013). There and sedentary lifestyle play a major role are mixed reports on the glycaemic (WHO, 2003). In this context, foods with indices/response of FM based foods. lower glycaemic properties are beneficial This is because few earlier studies in combating the rising prevalence of the (Lakshmi & Sumathi, 2002; Shukla & aforementioned disorders (Misra et al., Srivastava, 2014), had shown that FM 2011). preparations elicit a lower glycaemic Finger millet (FM) or Eleusine response compared to rice and other coracana L. is one of the most important cereals while others have equally shown millets consumed since ancient times. higher glycaemic responses for the This millet contains higher levels of millet- based preparations (Urooj et al., dietary fibre (12%), phytochemicals and 2006; Shobana et al., 2007; Shobana, minerals (Shobana et al., 2013). Hence, 2009). millet preparations are often considered In addition, FM-based food products as healthy dietary options for individuals with diabetes-friendly label claims with diabetes. Additionally, there is a (unpublished in-house market survey common perception that millet-based data) available in the market pose foods elicit a lower glycaemic response major challenges as there is usually although systematic studies in this no scientific backing for these claims. direction are lacking (Shobana et al., Systematic intervention studies on the 2013). glycaemic properties of FM-based foods Though millets were a part or diets using appropriate protocols are of traditional Indian diets, their scarce (Shobana et al., 2013). We have consumption has diminished earlier shown that the FM products used considerably, notwithstanding their in the present study (iso-caloric FM diet, superior nutritional value (NSSO, i.e. FM extruded snack, upma prepared 2014). Presently, polished white rice from decorticated FM, FM vermicelli and and refined cereal- based foods are the FM flakes) belonged to the medium to major staples in the southern Indian high GI categories (Shobana et al., 2018). region (Radhika et al., 2009) due to Continuous glucose monitoring government support for rice prices in (CGM) systems have been found to this region. Refined grains and their be useful to study the glycaemic products increase the glycaemic load response to diets over 24 hours for five of diets owing to their higher glycaemic consecutive days. We recently reported a and insulinaemic responses and could study with brown rice vs. white rice (WR) lead insulin resistance (Willett et al., based diets in overweight Asian Indians 2002; Radhika et al., 2009). Thus, it is (Mohan et al., 2014) using CGM. In the crucial to study the glycaemic properties current paper, we aim to evaluate the of ancient grains such as millets using glycaemic responses of FM-based diets appropriate methods so that they can be compared to iso-caloric WR based diets Glycaemic response of finger millet and white rice diets 457 in 14 normal healthy individuals aged by the Declaration of Helsinki, and was 20-40 y. approved by the Ethics Committee of the Madras Diabetes Research Foundation. MATERIALS AND METHODS All participants gave written informed consent before participation in the study. Participants Fourteen volunteers (7 males and 7 Dietary intervention females) in the age group of 20-40 years In a randomised cross-over design, with Body Mass Index (BMI) <22.9 kg/ volunteers were assigned to FM and m2 were recruited from our volunteer WR-based iso-caloric diets for breakfast, registry. Study participants were lunch and dinner for five consecutive excluded if they were overweight (BMI test days as shown in Figure 1. The ≥ 23 kg/m2) (WHO, 2004) or were on entire study protocol was explained to any special diet, had a family history of the participants in detail and they were diabetes, suffered from any illness or encouraged to discuss any concerns food allergy, used regular medications, they might have on any aspects of the or had a fasting blood glucose value of dietary intervention or protocol. They >5.6 mmol/l (>100 mg/dl) (American were further requested to abstain from Diabetes Association, 2003). Pregnant partying, smoking and alcohol as well or lactating women were also excluded as strenuous exercise during the study (Figure 1). The study was conducted period and this was ensured by daily according to the guidelines laid down dietary recalls. The intervention menu Figure 1. The study protocol Table 1. Finger millet and white rice based diets menu plan 458 † Quantity Quantity Menu Meal & Time Finger millet diet White rice diet (Main course and accompaniments) (g) (Main course and accompaniments) (g) Day 1 Breakfast (8.30-9.30AM) FMV upma 210 Rice vermicelli upma 275 Sambar 150 Sambar 150 Chutney-onion 75 Chutney-onion 75 Mid-morning (11.00am -12.00 noon) Lemon juice 200 Lemon juice 200 Lunch (1.00-2.00PM) Tomato flavored DFM 175 Tomato rice 175 Plain cooked DFM 150 Plain rice 100 Shanmugam S,RajagopalG,ChandrasekaranAetal. Mixed vegetable kootu 75 Mixed vegetable kootu 75 Cucumber raitha 100 Cucumber raitha 100 Rasam 100 Rasam 100 Mid-evening (4.00-4.30PM) Tea with sugar 150 Tea with sugar 150 FM based extruded snack 30 Masala puffed rice 30 Dinner (8.00-9.00PM) Finger millet adai 275 Rice adai 225 Mint coriander chutney 150 Mint coriander chutney 150 Day 2 Breakfast (8.30-9.30AM) DFM upma 250 Rice upma 240 Sambar 125 Sambar 125 Chutney-tomato 45 Chutney-tomato 45 Mid-morning (11.00am -12.00 noon) Vegetable soup 125 Vegetable soup 125 Lunch (1.00-2.00PM) DFM plain (cooked) 275 Plain rice 275 Curry spicy gravy 100 Curry spicy gravy 100 Cabbage poriyal 75 Cabbage poriyal 75 Rasam 100 Rasam 100 Curd 75 Curd 75 Mid-evening (4.00-4.30PM) Finger millet bread sandwich 168 Dhokla sandwich 100 Dinner (8.00-9.00PM) Finger millet dosa 220 Rice dosa 200 Veg. kurma 175 Veg. kurma