There is unprecedented increase in prevalence of type II diabetes among African city dwellers and it has been attributed partly to shift from taking whole grain maize porridge for breakfast to taking bread made from refined wheat flour.
These findings have been published in a study carried out by researchers from University of Pretoria in South Africa, who found out that, porridge from whole grain maize flour was less digestible compared to bread. What this means is that, after drinking porridge prepared from whole grain maize flour, there is gradual release of sugar into the blood system compared to eating bread. Gradual increase of blood sugar has lower contribution to diabetes compared to rapid increase in blood sugar resulting from refined carbohydrates.
Similar increase in cases of diabetes have been made among the Aborigines of Australia and other rural communities who after urbanisation experienced exceptional increase in incidence of diabetes due to dramatic shift from taking whole grain cereal foods to taking refined carbohydrates.
The other main advantage of whole grain flours in addition to slow release of sugar is that they are high in fibre which is associated to lower risks of diabetes.
Meree, V.B, Erasmus, C. and Taylor, J.R.N. (2001). African Maize porridge: A food with slow in vitro digestibility. Food Chemistry, 72, 347-353