Consumption of some Nigerian local rice varieties and effect on development of insulin resistance and obesity in Drosophila melanogaster

There is evidence to suggest that the increased incidence of insulin resistance and obesity is associated with the consumption of energy-dense and highly processed foods like polished rice. This study, therefore, investigated the effects of consumption of selected local rice varieties on some markers of insulin resistance and obesity using Drosophila melanogaster. Five different local rice varieties (Jamila, Kwandala, Mai-bakin carki, Yar-katabore and Yar-washagi) were subjected to proximate composition analysis, which showed that the unpolished local varieties had a better deposit of nutrients. Thereafter, adult flies were raised on diets containing either polished or unpolished forms of the five different local rice varieties for seven days and thereafter, analysed for weight and locomotor ability, as well as the levels of glucose, trehalose, glycogen and triglycerides in the hemolymph and expression levels of ACC and Pepck genes. Drosophila melanogaster flies on the polished rice groups showed increased weight, hyperglycaemia and hyperlipidaemia, compared to those on the unpolished rice (p<0.05). Changes in gene expression were in line with the biochemical changes. The study, thus, suggested that the substitution of polished with unpolished local rice may reduce the risk of insulin resistance and obesity, as well as their related complications.