Gordon McDougall

There is increasing evidence that non-nutrient components of fruit and vegetables (FAV) may have key roles in providing the health benefits associated with diets rich in FAV. The main thrust of my research examines the possibility that phytochemicals in plant foods can influence human health. The focus has been on soft fruit, particularly on polyphenols in berries, as there is already evidence for the effectiveness of these components from other foods and beverages and berries are a particularly rich and palatable source.

My research has four main overlapping and interdependent areas:

• Establishment of bioactivities relevant to human health for berry polyphenols
• Analysis of the composition of polyphenols in bioactive extracts to confirm structure-activity relationships for effectiveness and to assess the stability and bioavailability of active components in the human body
• Development of high through-put methods to analyse the inheritance of bioactive polyphenols in berries, to link the ‘health' phenotype to the genotype of The James Hutton Institute’s elite germplasm collection.
• Assess environmental influences on the accumulation of levels of bioactive components.

To accrue evidence that berry phytochemicals have bioactivities that can influence human health or mitigate disease progression, I have initiated collaborations with a range of biomedical experts who have relevant model systems for cardiovascular health, neurodegeneration, diabetes, and cancers. These model systems range from in vitro enzyme screens, ex vitro cell or tissue studies to animal or human trials. I also developed key in-house screens and assays. In each case, extracts with closely defined compositions have been used and the studies include analysis of the metabolic fate of the components to define the mechanisms of action and the candidate active ingredients. In human trials, bioavailability studies of the levels of metabolites in blood, urine and faeces have been completed.

Through these studies, I have confirmed that different polyphenol components from berries can have different effects in different model systems and that overall efficacy is often decided by a combination of bioactivity, stability and longevity/bioavailability in the system. These cross-disciplinary collaborations have led to close associations particularly with the University of Ulster and the University of Dundee. These approaches are currently being applied to studies on Alzheimer’s disease through the EU-funded BrainHealthFood project.

Along with Ilka Abreu and Sean Connor, I have established novel MS based methods for following polyphenol diversity. This has enabled us to begin to link polyphenol inheritance to the genetic maps being developed for raspberry and blackcurrant by the Genetics Programme (with Rex Brennan and Julie Graham). Through this approach, we hope to enable accelerated breeding of improved varieties with elevated levels of healthy components. Importantly, I have also directed research to establish if environmental conditions influence polyphenol levels, which has informed us that certain genetic markers are consistently associated with enhanced polyphenol content across years with widely differing climatic conditions. The high-through-put methods developed have been employed to track the diversity of polyphenols from growing berries under different agronomic conditions, in different latitudes or after different processing methods with collaborators from across Europe (ClimaFruit Project). These areas form part of the new programme of work planned for the Scottish Government.