Sustained postprandial hyperglycaemia is an independent risk factor for cardiovascular complications and death. Intensive glucose control is the predominant factor to prevent the development of chronic complications in Type 2 Diabetes Mellitus (T2DM). The investigators have shown that phytochemical-rich extracts (in this case anthocyanins and their derivatives) can attenuate glucose response and there is also strong evidence for the role of fibre. Here a selected barley line (rich in anthocyanins and (1,3;1,4)-β-glucan) will be compared to a control barley and control wheat in an acute human dietary intervention (with n=15 healthy volunteers) to explore the potential to modulate postprandial glycaemia and insulinaenemia. An additional secondary outcome will include metabolomics analysis of the blood plasma and urine to detect differences in bioactive compounds including phytochemical metabolites. This will help ensure that barley lines being bred for human food can also deliver benefits for health.

Barley is an important Scottish crop in terms of contributing to the distilling industry but underutilised as a healthy (and potentially sustainable food). The investigators have shown (unpublished data) that barleys entering the food supply chain are not bred for food but are often grain destined for distilling and not rich is components of value for human nutrition, for example (1,3;1,4)-β-glucan, micronutrient vitamins and minerals as well as bioactive phytochemicals associated with reduction of non-communicable diseases such as type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD).

Current research is exploring the potential of specifically bred food barleys to require less inputs in terms of nutrients and pesticides and grow on more marginal lands providing farmers with a crop harvested at a different time of year, mitigating against unpredictable weather and a changing climate. It is important that these barleys also deliver benefits to human health. There are established health claims with regard to the lipid lowering effect of (1,3;1,4)-β-glucan and phytochemical-rich barleys could also potentially reduce blood glucose, an important factor leading to metabolic deregulation and subsequent disease development. This would meet the needs of people choosing a healthy lifestyle, as well as those living with or at risk of T2DM. From the food collections being developed at the James Hutton Institute, an accession (high in (1,3;1,4)-β-glucan and phytochemicals) will be selected and tested in an acute dietary intervention to determine if postprandial blood glucose levels are reduced. This will be compared to control barley and wheat products.

Inclusion Criteria:

Apparently healthy male and female subjects with Diabetes Risk Score ≥ 7 points

Exclusion Criteria:

• Type 1 diabetes
• Type 2 diabetes controlled with medication
• Coeliac Disease
• Eating disorders (anorexia, bulimia, binge eating or night eating syndrome)
• Food allergies/intolerances
• Any significant health issues
• Breastfeeding/ Pregnancy
• Addiction to any substances
• Are unable to give written informed consent