Local Rice Consumption and the Risk of Developing Insulin Resistance in Wistar Albino Rats

Abstract

Rice consumption, particularly of highly processed white rice (WR), has been associated with increased risk of insulin resistance (IR). This study aimed to compare the impact of consuming WR versus brown rice (BR) from five common local rice varieties in Nigeria on the development of IR using a Wistar albino rat model. Five local rice cultivars (Jamila, Kwandala, MBC, Yarkatabore, Farar jalof) were collected, with one set kept unpolished (BR) and the other polished (WR). Proximate analysis and quantification of bioactive compounds (total phenols, flavonoids) were performed. Wistar albino rats were fed either a normal diet, high-fat diet, or diets containing 100% BR or WR for 12 weeks. Body weight, fasting blood glucose, glycogen, triglycerides were assessed. BR varieties had higher protein, fiber, and carbohydrate content compared to WR. BR also exhibited significantly greater total phenolic and flavonoid contents. Rats fed BR showed no significant weight gain (p<0.05), while some WR groups gained weight. Fasting blood glucose was elevated in WR groups versus control and BR groups. Blood glycogen was lower, and triglycerides higher, in certain WR groups. Consumption of BR varieties may confer protective effects against IR compared to WR in this rat model. These findings highlight the potential metabolic health benefits of incorporating local BR varieties into the diet to mitigate development of chronic disorders.