Resistant Starch 5: A Novel Approach to Reducing Postprandial Glycaemia and Lipaemia

In 2016, diabetes caused about 1.6 million deaths, and the global prevalence of diabetes in 2019 was estimated to be 9.3%, projected to rise to 10.2% by 2030. Cardiovascular diseases (CVDs) are one of the common complications of diabetes which may lead to an early death. Correspondingly, the Scientific Advisory Committee on Nutrition (SACN) recommended improving the quality of dietary carbohydrate in relation to human health and eating more dietary fibre. Dietary carbohydrate, in the form of starch, can form interactions with other components within the food matrix, giving it the potential to reduce the digestibility and absorption of these components. Starch can be processed to form a kind of dietary fibre called resistant starch. Resistant starch (RS) is the fraction of starch that is not broken down to glucose in the small intestine within 120 minutes of being consumed. It is therefore fermented in the large intestine and serves as a source of fibre. Resistant starch 5 (RS5), otherwise known as amylose-lipid complexes, can be formed by complexing starch with dietary fat during processing/cooking. A recent study by Oraee et al. (2017) revealed that reheating a starchy carbohydrate meal in the presence of fat significantly lowers postprandial triacylglycerol (TAG) response. However, the mechanism behind this effect is unknown. Also, the effects of RS on blood fat, and specifically postprandial lipaemia, a major factor for the development of CVDs, are unknown. Therefore, this project aims to identify the mechanism behind the effects of RS5 on the regulation of glycaemia and lipaemia via in vitro (INFOGEST model) and in vivo (stable isotopes) methods. Overall, the outcome of this research will proffer recommendations on the use of RS5 as a functional food ingredient in the management and subsequent treatment of illnesses such as diabetics and lipaemia, thereby promoting healthier nutrition and lifelong health.