Title : Effect of Apple and Blueberry Fruits on Glycaemic Index of White Bread
High glycaemic index foods have been implicated in postprandial hyperglycaemia, which is the sudden rise in blood glucose after a meal. Uncontrolled hyperglycaemia leads to diabetes mellitus, which on the other hand leads to many complications such as neuropathy, retinopathy, microangiopathy, nephropathy, ischaemic heart disease and stroke. Fruits have been described to be good source of carbohydrates, vitamins and minerals and are considered vital for good health. They also contain viscous fibres that help to control glucose responses by deferring the digestion and absorption processes. Apple and blueberry fruits are two examples of such fruits with low glycaemic index (GI). The glycaemic index of a food measures the power of the food to increase the blood glucose after a meal. Glycaemic index (GI) of many these fruits has been determined but their effect on other carbohydrate-rich foods has not been investigated. In the present studies, effect of apple and blueberry fruits on the glycaemic index of white bread were observed. Thirty volunteered participants (aged: 20 – 24 years) were engaged in the study. The participants were instructed to report to the laboratory after an overnight fast and capillary blood samples were collected by finger-pricking and baseline (fasting) blood glucose levels were determined. The participants were then grouped into three of six membered. The participants were then served with 50g of glucose dissolved in a quantity of water and blood glucose levels determined at 15, 30, 45, 60, 90 and 120 minutes. On the second day, the experiment continued after the baseline glucose levels have been taken, 50g white bread was consumed by each participants and postprandial blood glucose levels were determined at intervals as described above. On the third day, each group consumed 50g white bread and fruit in different order; group one consumed bread after 5 minutes of fruit consumption, group two consumed both bread and fruit simultaneously while group three consumed fruit after 5 minutes of bread intake. The results of the findings reveal that both apple and blueberry fruits significantly (p<0.05) lowered the glycaemic index of the white bread (75.93% ) to 38.06% and 39.26% respectively. The glycaemic index lowering effects was well pronounced when both the fruits and the bread were taken concomitantly. In conclusion, taking apple or blueberry fruit and carbohydrate-rich food together may be useful to diabetic people by adequately improve the normalcy of their blood glucose. It may also be beneficial to the healthy people by helping them to avoid excessive insulin response, diabetes, coronary heart disease and hypoglycaemia between meals.