Development and application of phenolic-rich oats for the maintenance of cardiovascular health

UK products composed of >51% whole grains can claim, "People with a healthy heart tend to eat more whole grains foods as part of a healthy lifestyle". A number of components present in wholegrain have been hypothesised to contribute to the beneficial cardiovascular effects associated with wholegrain consumption, including phenolic acids. Recent dietary interventions in humans using phenolic acid-rich foods (blueberry, coffee, champagne) are capable of improving the function of the circulatory system. Oats are a rich source of phenolic acids, although the degree to which they contribute to the human health benefits associated with wholegrain intake has not been investigated in humans. We hypothesise that phenolic acid-rich oats will be effective at inducing acute, beneficial improvements in circulatory function in humans thus contributing to a healthy cardiovascular function.
Building on existing human work conducted in our laboratory, this study is designed to determine how phenolic acids may enhance human vascular function by focussing on how they modulate the function of the human circulatory system. The proposal will provide crucial information in three areas. Firstly, it will provide information regarding the variation in phenolic content that exists in both commercial varieties of oat products and newly developed ones. Secondly, we will test the ability of phenolic acid-rich oat intake to produce improvements in circulatory function in healthy humans using established, gold standard, clinical measures of blood flow around the body. Thirdly, we will strive to determine the processes in the body by which these beneficial effects on blood vessel function are mediated. The outcomes of this proposal have implications for exploiting the potential beneficial health effects of phenolic acids of the diet, particularly with relation to oat and other wholegrain intake. Oats are a sustainable, relatively cheap, UK product that offers an alternative to more expensive and less sustainable foods/beverages such as cocoa and berries, also shown to exert such biological effects on the circulation.
The concept of healthy ageing is rooted at the core of this proposal through the application of sound dietary recommendations. Data emanating from the proposal are necessary before academia/industry may work to exploit such public health properties of foods in the future. There has been a large growth in the desire for such functional foods (21% market growth in the USA) and cause-and-effect data are essential for the development of EFSA/FDA health claims on specific oat products. The impact of bad diet/lifestyle and obesity on blood vessel health/disease is well reported and whilst wholegrain oat intake is recommended for the maintenance of a healthy circulation and heart, no studies to date have provided evidence for the health effects of the polyphenols in oats. Over three million Britons currently suffer from cardiovascular-related problems in the UK, with annual costs for the health system exceeding £30billion. Yet it has been estimated that 80%-90% of premature cardio-vascular events are preventable, and a healthy diet is paramount in this. We aim to work with a major food company, PepsiCo, to design and test a novel oat food/beverage with the potential to counteract the loss of correct blood vessel function. Understanding more about how specific diets may promote healthy cardiovascular aging will help us to define more effective public health advice and reduce the cost of services, by encouraging the population to make more informed healthy food choices.

The intake of dietary-derived phenolic acids, including ferulic acid, caffeic acid and p-coumaric acid have been shown to improve microvasculature blood flow and large artery function in humans. These beneficial effects have been attributed to their potential to improve endothelial function by increasing NO availability. This proposal is designed to test the hypothesis that phenolic acids found within oat-based diets may promote vascular function via their potential to enhance NO bioavailability to the vascular endothelium, through effects on NADPH oxidase activity and NO production.

Initially, we will analyse various oat varieties for their polyphenols profile, selecting low and high containing ones for the clinical work. Acute blood flow changes in response to oat intervention will be assessed by conducting a randomised, controlled, crossover intervention study to assess vascular function in healthy human volunteers: Vascular function will be assessed by flow mediated dilatation (FMD) and laser Doppler imaging (LDI). In order that we can make causal relationships between the phenolics in the oats and vascular outcomes, we will also assess plasma levels of phenolic metabolites by using established analytical methods (HPLC with UV-visible, fluorescent and mass detection). We will also assess the modulation of endothelial NO levels by measurement of the circulating NO pool using gas-phase chemiluminescence and the activity of NAPDPH oxidase (enzymatically and by flow cytometry). Metabolic phenotyping/profiling will be undertaken on urine samples (baseline and 24 h) and blood (3 time points) using 1H nuclear magnetic resonance (NMR) spectroscopy. Lastly, the modulation of NO cell signalling (PI3 kinase/Akt and downstream eNOS levels) will be assessed in cultured endothelial cells exposed to physiological phenolic acid metabolites by Western immunoblotting.

Impact: This proposal will further our understanding of the impact of diet on human cardiovascular health. The proposal will facilitate underpinning science to provide the growing population with a sustainable, secure supply of safe, nutritious, and affordable high-quality food. The outcomes of our research will encourage the development of a variety of new, healthy oat-based food products highly relevant to the UK market. The proposal addresses the strategic priority: Global Food Security: sustainable, healthy and safe diets and has relevance to the strategic grand challenge 1 within the BBSRC delivery plan (2012-2015): "Food security". The proposal will also impact on the BBSRCs Fundamental bioscience focus area in that it will provide underpinning science for the understanding and prevention of cardiovascular disease throughout a healthy diet.
Industry: There is a huge, and growing, demand for novel functional foods that provide health benefits and this is particularly the case with those designed for cardiovascular health. Our collaboration with PepsiCo (10% IPA), who market oat-based foods through the Quaker label, clearly indicates significant industrial interest. In the US alone (the largest market for functional foods) a 21% growth in the functional foods market is expected in the coming years owing to the growing demand for functional foods, expected to reach $8.62 billion by 2015. PepsiCo's agreement to part-fund our proposal stems directly from their interest to produce novel healthy foods determining cause-and-effect data relating to polyphenols intake and cardiovascular efficacy. Our research will provide industry with the confidence to invest in new polyphenols-containing products aimed at vascular enhancement and will provide a foundation for the development of EFSA/FDA health claims on specific polyphenol containing products. Thus, the proposal will be applicable to a variety of companies manufacturing wholegrain-based products, aiding the development of novel products over the next 5-10 years. This proposal will provide the scientific basis for the design, and manufacture of novel oat and other phenolic acid containing products for future exploitation.
General Public: Understanding more about how specific diets may promote healthy cardiovascular aging will have important societal and economic impacts and will help allow the public to make more informed choices regarding healthy diet. In the UK, over three million people currently suffer from vascular-related illness and healthy food/lifestyle choices are known to help slow vascular ageing and improve the quality of life. There is wide support for this type of research, as previous BBSRC surveys have shown. Furthermore, consumers have a growing awareness of food sustainability and origin/locality (i.e. food miles). This proposal will provide evidence for the health effects of oat-based foods, a relatively affordable crop available in the UK, unlike cocoa, tea and blueberry, which are more expensive and less sustainable. Although the study findings have most relevance to those at greatest risk of vascular dysfunction, it has relevance for all individuals. The increase in the older population over the next decade will create further demands on health services and this proposal is designed to provide a potential long-term prevention strategy to slow vascular ageing. The public interest in such science is high, thus the proposal will be highly applicable for wide dissemination through public engagement events.
Government agencies involved in promotion of public health (FSA, DOH, and DEFRA): Understanding more about how specific diets may promote healthy aging and modulate disease progression will help agencies inform the public and encourage them to make more informed and healthy food choices. We anticipate being able to make recommendations about which foods may be most beneficial in promoting healthy cardiovascular ageing.