Overview of the Composition of Whole Grains' Phenolic Acids and Dietary Fibre and Their Effect on Chronic Non-Communicable Diseases

Abstract

Chronic non-communicable diseases are the major cause of death globally. Whole grains are recommended in dietary guidelines worldwide due to increasing evidence that their consumption can improve health beyond just providing energy and nutrients. Epidemiological studies have suggested that the incorporation of whole grains, as part of a healthy diet, plays a key role in reducing one's risk for cardiovascular diseases (CVDs), obesity, type 2 diabetes (T2D) and cancer. Phenolic acids and dietary fibre are important components found in whole grains that are largely responsible for these health advantages. Both phenolic acids and dietary fibre, which are predominantly present in the bran layer, are abundant in whole-grain cereals and pseudo-cereals. Several studies indicate that whole grain dietary fibre and phenolic acids are linked to health regulation. The main focus of this study is two-fold. First, we provide an overview of phenolic acids and dietary fibres found in whole grains (wheat, barley, oats, rice and buckwheat). Second, we review existing literature on the linkages between the consumption of whole grains and the development of the following chronic non-communicable diseases: CVDs, obesity, T2D and cancer. Altogether, scientific evidence that the intake of whole grains reduces the risk of certain chronic non-communicable disease is encouraging but not convincing. Based on previous studies, the current review encourages further research to cover the gap between the emerging science of whole grains and human health.

Keywords: cancer; cardiovascular diseases (CVDs); dietary fibres; obesity; phenolic acids; type 2 diabetes (T2D); whole grains.

Figure 1

The influence of whole grains on physiologic parameters regulating body weight and composition is mediated by the structural and physicochemical features of whole-grain meals. IR: insulin response; GLP-1: glucagon-like peptide-1; PYY: peptide; SCFA: short-chain fatty acid.

Figure 2

The link between obesity and other chronic non-communicable diseases and proposed mechanisms of obesity and increased cancer risk. IGF-1: insulin-like growth factor-1; IGFBP-2: insulin-like growth factor binding protein-2; IGF-1: insulin-like growth factor -1; SHBG: sex hormone-binding globulin.