Nutrient composition and glycemic response of five species of yam (Dioscorea) commonly consumed in South-East Nigeria

Abstract

Background: Diabetes is one of the leading causes of death in the world especially in developing nations and nutritional management of blood glucose levels is a targeted tool in its prevention and management.
Objective: To determine the nutrient composition and glycaemic response of varieties of tubers diascoreaspp(yams) commonly consumed in south-eastern Nigeria
Methods: The study adopted a cross sectional design and simple random techniques. Forty participants were recruited for the study andfive species of yam Dioscoreaspp (D.rotundata, D.cavennesis, D. alata and D. dumetoru (white and yellow)) were purchased from new market in Enugu and from a farm in Umuahia, Nigeria. They were sorted, peeled, washed, cooked to tender and analyzed using AOAC method. Glycemic response was determined by the method described by Joint FAO/WHO ExpertConsultation.A structured questionnaire was used to elicit information on socio-demographic and anthropometric indices from the respondents. The blood glucose test was done using Accu-check Active meter and strips.
Results: The mean BMI of respondents was 21.05±1.39kgm-2 and 24.75±3.71kgm-2 for male and female respectively. A significant differences (p<0.05) was found in the proximate and micronutrient (vitamins and minerals) composition of the varieties of yam. The study revealed that white yam(D.rotundata) gave the highest glucose response (110.8mg/dl±6.63 and 102.4mg/dl±4.12)after 60 and 90 minutes respectively, while after 120 minutes, water yam(D.cavennesis)gave the highest (104mg/dl±6.10). However, both species
of “Una”dioscoreadumentorumgave the lowest glucose response.
Conclusion: The variations in the nutrient composition and glycemic response of the varieties of yam can be explored for better dietary management especially for diabetes patients.