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The food supply chain is subject to potential contamination with natural and industrial toxins. Food can contain pathogenic microorganisms, natural toxic compounds or industrial chemicals added intentionally or accidentally. While acute food poisoning is relatively rare, long-term effects of food toxins are an area of concern and, therefore, routine testing of foods at different stages of agrifood processes is legally required. 

Toxin testing is typically carried out using analytic methods like high-performance liquid chromatography (HPLC) or liquid chromatography-mass spectrometry (LCMS), using commercially available standards, or immunological methods. Chemical and immunological analyses are very specific and typically detect a single analyte. Targeted LCMS also requires standards for the toxins under analysis.

The number of toxins with distinct chemistry, but similar toxicity, is often substantial. For example, there are 300 different known mycotoxins and 700 different pyrrolizidines. The related substances can be produced by the same pathogenic organism or by the metabolism of the toxin and may escape detection by normal analytical techniques. For some toxins, therefore, separate tests exist for the original and the metabolised toxin. Thus, it is impossible to test for such a wide range of mycotoxins using antibodies or LCMS.

Cell-based assays

Cell-based assays utilise whole cells as indicators of a specific biological process and can be used to detect chemicals which elicit toxicity. Cell-based assays can measure a variety of biological outcomes utilising parameters, including cell viability, transcriptional changes or signalling events involving protein-protein interactions. Cell-based analysis of signalling interactions can lead to the development of immunological tests, biochemical assays, and biosensors.

Cell-based assays are used in the pharmaceutical sector for pre-clinical screening of novel therapeutic compounds but have also been used for food toxicity testing. Examples include grain-borne mycotoxins, packaging-derived xenobiotics, shellfish toxins, or pyrrolizidine alkaloids in herbal extracts. Cell-based assays can simply measure cell viability (including toxicity or, conversely, growth stimulation by endocrine activity) but can also interrogate specific signalling events affected by toxins. Whole-cell bioassays based on bacterial cells, yeast and nematodes have been developed and are used for the detection of food and environmental toxins in some commercial settings. Cell-based assays can provide an alternative for and a complement to immunological and chemical testing. As for these established techniques toxin detection is influenced by food matrices.

The advantages of cell-based assays include:

• Automatic incorporation of bioavailability and viability testing.
• Ability to test for a group of chemicals with a similar toxicity profile.
• Ability to identify toxins for which no established standards currently exist.
• This is an active area of research, and the full potential of cell-based assays has not been fully realised yet. 

Initiatives to support consumers in making healthy food choices have failed to help Scotland meet its dietary targets. It is appreciated that this will not be achieved by a single approach. Reformulating food to be healthy, sustainable, and most importantly acceptable and affordable, has genuine potential in supporting these initiatives, but only if the supply chain is robust and economically viable. 

Our previous research has identified several crops that could be sustainably grown in Scotland (hemp, buckwheat, pea, and fava bean), with the main objective to address protein intake and reducing emission targets associated with livestock production. From a food formulation perspective, these crops are extremely versatile. For example, hemp grain can be milled to produce flour, and pressed to produce oil and dairy alternatives, with the co-products also having economic value contributing to an effective circular economy. 

The formulation of these crops can also contribute fibre, micronutrient minerals and vitamins and valuable bioactives to the diet. We have demonstrated that bread reformulated with hemp flour reduced hunger and modulated hormones associated with satiation. Buckwheat is a prime example of how we have developed a formulation to target the rise in postprandial glucose, which has been strongly linked to the development of type 2 diabetes mellitus (T2DM). This formulation was shown to reduce blood glucose in people living with T2DM (controlled by metformin or diet). Furthermore, the formulation is also versatile and could be included in a range of products providing a much-needed and familiar range of foods and drinks to support those looking to have a healthy lifestyle but finding it difficult to make the correct dietary choices. Successful implementation of these strategies requires supply chains to be in place and this includes primary production. Increasing demand necessitates bringing all actors within the supply chain together.

The supply and demand sides of Scottish food and drink are disconnected. Scotland produces food and drink products of the highest quality from diverse, internationally renowned, and often challenging land and marine environments that require careful management to balance production, biodiversity, and amenity. However, many Scottish food producers struggle to stay in business. 

Food consumption in Scotland tends to be associated with low intake of fruit and vegetables and with high rates of obesity and related ill health. These associations tend to be stronger for the economically disadvantaged. Economic disadvantage, marked by insufficient and insecure incomes, is also the main driver of food insecurity. The Family Resources Survey estimated that in 2019-20 eight per cent of Scottish households experienced food insecurity. Given that the average number of people per household in Scotland was 2.15 in 2019, it is likely that more than nine per cent, and possibly nearer 15 per cent, of the Scottish population has experienced some level of food insecurity in recent years.

Efforts are being made to bring Scottish producers and consumers together, such as through farmer’s markets. In parallel, networks have developed to supply large food banks which, in turn, provide smaller organisations and consumers with free or heavily discounted food and drink products. Such networks have expanded significantly since the 2000s and now cover much of Scotland. 

These networks remain under-studied in Scotland. However, research done elsewhere raises questions about the extent to which their charitable and often eligibility-dependent provision of food can address the economic conditions that they seek to alleviate and be compatible with the Scottish Government’s dignity principles. Working with people who have faced food insecurity is particularly important to build bridges across the divide between Scottish food production and consumption. While there is much quantitative evidence on overall consumption patterns, not enough is known about the attitudes of low-income consumers and the consumption habits of food-insecure people.

Crops, meat, dairy and fish represent some of Scotland’s most commercially important produce. For example, beef production is important for Scottish agriculture. In 2017 Scottish cattle farmers generated 27% of all Scottish agricultural output from the sale of animals for meat production and breeding, making it the biggest single sector of the Scottish agricultural industry. These food groups are also key components of a ‘healthy’ diet, yet the production systems can have quite different impacts on greenhouse gas emissions. Supply chain mapping allows resilience strategies to be put in place to rapidly react when there are supply shortages or changes in demand. Within the UK, generic maps of the supply chains have been produced. Generally, supply chain mapping is not commonly used to address compatibility with dietary guidelines, address alignment with consumption and purchase patterns, or assess how nutrient-density flows may impact the Scottish diet.

The UK’s EU exit and the Covid-19 pandemic have negatively affected many of these supply chains in different ways, with the introduction of export barriers having a particularly negative impact on sectors with a limited domestic market. Also, the concentration of consumer demand around some of the products in a specific food chain leads to imbalances in terms of what is produced and what is domestically consumed. Whilst the Scottish supply is sufficient to cover the Scottish consumption of several products, there are cases, like fish, where the consumption is only half of what is recommended, and full compliance with dietary recommendations cannot be satisfied.

To ensure healthy, sustainable, and secure food environments, it is important to understand how our diets relate to food supply chains - what is being produced, what is imported and exported, and how supply relates to what we eat and what we should be eating. Each supply chain has its own, often complex structure, for example, fish and shellfish operate across different sectors (fisheries and aquaculture), with sub-sectors having distinct supply chain routes, operational models, and timescales to market.

There is a need for dietary shifts to make the transformation towards diets that are healthier and more environmentally sustainable. In the past 50 years, we have seen a shift towards unhealthy diets high in calories, and heavily processed and animal source foods. Transitions to unhealthy diets are increasing the burden of obesity and diet-related non-communicable diseases and are contributing to environmental degradation. Dietary guidelines are an important behaviour change policy tool to guide consumers in terms of the foods and diets they should be eating. However, healthy diets alone do not produce substantial reductions in greenhouse gas emissions. Therefore, dietary guidelines need to include recommendations for environmental sustainability.

A few countries have started to produce dietary recommendations for health and environmental impacts. In addition, dietary guidelines in most countries fail to take account of reasons behind peoples’ food choices, such as habits, preferences, affordability, circumstance, culture, and social norms. Another issue with the implementation of nutrient-based dietary guidelines is that people eat foods, not nutrients. Foods contain multiple nutrients that cannot be readily swapped for one another. Therefore, more food-based interventions are necessary for effective behaviour change strategies towards more healthy and sustainable dietary patterns.

Evidence on existing interventions

Food purchasing is a key determinant of food consumption, and interventions targeting the nutritional and environmental quality of food prior to or during shopping presents a clear opportunity for effective behaviour change. Individual-level interventions previously identified as effective behaviour change techniques include tailored dietary advice, information, self-monitoring, and personalised feedback. Interventions implemented in grocery stores, particularly those that manipulate price, suggest that swaps, and perhaps manipulating item availability, have an impact on purchasing and could play a role in public health strategies to improve health. Using swaps to promote health would be a scalable and low-cost intervention, but currently there is limited evidence on its effectiveness. The success of offering swaps depends on consumers accepting the suggested swaps, but most studies thus far did not explore why swap acceptance rates could be low. Acceptance could be low due to how swaps were framed, perceived to restrict freedom and personal autonomy, and perceived to be less palatable. Also, many consumers put lower importance on health messages and higher importance on taste and price. Indeed, product costs have been a particularly crucial factor for those on lower incomes, and lower price can encourage choices of healthier products more effectively than health status labels.

The development of behaviour change interventions requires an understanding of facilitators and barriers for consumers to make food choices that are healthier and more environmentally sustainable, but also economically affordable. Currently we know relatively little about how individuals interact with their food environment and apply their perceived knowledge of healthy and sustainable diets. Several factors including socio-economic, life-stage, demographic, and geographic background, can drive individual decisions and behaviours when selecting foods and drinks, indicating that behaviour change interventions require a more in-depth understanding of drivers of individual food choice, on a more granular level.

There has been a lack of progress in changing dietary patterns in the Scottish population despite almost three decades of policy and government investment in interventions intended to address it. Self-reported dietary intake has been consistently poorer in more deprived households compared to more affluent households in Scotland and has declined further in recent years in the UK. Financial constraints and related stress and anxiety leading to reduced access to healthy foods, and reduced access to physical spaces and opportunities to practice physical recreational activities and food insecurity, all increase obesity risk.

Public health scientists have theorised that increased food insecurity, household economic disruption, household stress, and interruptions in healthcare will contribute to obesity and related co-morbidity. COVID-19 exacerbated existing health inequalities via the health effects of social and economic upheavals due to the pandemic, including job losses and social isolation. Therefore, it is likely that dietary patterns will further deteriorate in the post pandemic context unless dietary behaviour change interventions take account of household, socio-economic and individual circumstances in their design.

Social Prescribing

Many council areas in Scotland, including Aberdeen city, experienced declines in household income and increased health inequalities in 2020. Regeneration programmes have historically included interventions intended to improve nutrition in low-income communities. Such interventions are often designed and implemented in partnership with local communities and are commonly delivered via Health and Social Care partnerships in Scotland. One such is social prescribing (SP). SP recognises that people’s health and wellbeing are mostly determined by social, economic, and environmental factors, and seeks to address these needs in a holistic way. SP enables health professionals to refer people to a range of potentially beneficial, local, non-clinical services in addition to, or in place of conventional medical treatments. After initial referral from a primary care professional, a “link worker” evaluates the client’s needs and produces a “social prescription”, which either refers the client to a local enterprise offering a suitable form of support or directly prescribes a recommended course of action.

Social prescribing schemes are mainly focused on improving mental health and physical wellbeing, generally targeting people from lower income families who have a higher risk of suboptimal nutrition and mental health issues. Therefore, SP offers potential to support improved food practices in SP client households, which is currently under-realised: the social prescriptions issued are not necessarily based on the best scientific behaviour change evidence and may not be made with full awareness of all potentially relevant services offered by local authority and third sector partners.

Members of low-income families, living in the most deprived areas in Scotland are particularly at risk of suboptimal nutrition and obesity. While many different interventions and initiatives have been introduced into communities over the last 20 years to try and tackle obesity in lower income households, there is little evidence that such strategies have been successful and that they are rarely robustly evaluated. Uptake from individuals living in deprived communities is often low, and intervention design is often based on available community skills and resources rather than scientific evidence about what is required to change behaviour.

Generally, diets in Scotland are unhealthy and damaging to the environment. One solution is moving the population to more sustainable diets that are healthy and have a low environmental impact. For instance, a more plant-based diet, which comprise only small amounts of meat. Plant-based diets can have multiple health benefits when they include more whole foods such as fruit, vegetables, pulses, nuts, and whole grains. These diets typically have a lower environmental impact than meat-heavy diets.

Sustainable diets can have multiple co-benefits for health and the climate, which line with the Scottish Dietary Goals and Scottish Government emissions reduction targets to net zero by 2045. However, little is known about the type of food and meals people eat in place of meat and how it might change an overall diet. It can’t be assumed it will always be healthier. Hence, we need to be cautious about what we eat in place of meat. Plant-based convenience foods are increasingly available, but many are classified as highly processed which tend to be high in salt, sugar and fat, and if consumed regularly, could have negative consequences for health and the environment.

To support the right sort of dietary change, we need to understand barriers – both those people perceive and those they experience in the real world. While access and affordability are commonly cited barriers, social and cultural aspects of food choices are often overlooked, including the desire for convenience and familiarity. Understanding attitudes and personal, social, and situational factors driving or inhibiting the adoption of a more plant-based diet is critical for the development of policy interventions to change consumer behaviours and consumption patterns to create a healthier population and a more sustainable food system.

Studies suggest that there is, or has been, perceived value in the production of food and drink products with higher-value status in Scotland. However, the extent to which higher-value food and drink products generate additional economic value for their producers and regions of production has been much debated. The terms of that debate have become more complex since the UK left the European Union (EU).

Take, for example, EU schemes that protect food and drink products with specific geographical characteristics. The two main schemes - Protected Designation of Origin; and Protected Geographical Indication - are intended to provide consumers with reliable information and to promote fair competition, respect for intellectual property rights and the integrity of the internal market.

Such geographical protection came under UK control in January 2021. Products with existing EU protection were registered automatically but new registrations must now be made in Great Britain, to protect the name here, and also in the EU, to protect the name there and in Northern Ireland. To add to this complexity, some countries the UK is eager to secure trade deals with, such as the USA and Australia, have been reluctant to recognise such geographical protection

This project provides evidence to help policymakers and businesses understand the economics of higher value food and drink products and the impacts of the EU exit and other trade developments on them.

A key challenge for researchers and policymakers is to produce and implement evidence-based guidelines for the UK food system to reduce obesity trends. Some 65% of the Scottish adult population is classified as living with overweight or obesity. In general, the Scottish diet is poor quality being too high in calories, processed foods, fats, sugar, and salt; it is equally too low in fibre, oily fish, and vegetables. Poor diets are a major contributory factor driving diet and health inequalities. Diet inequalities are notably socially patterned according to socio-economic status, where overweight and obesity prevalence is higher in socially disadvantaged groups.

Dietary fibre is found inherently in plant derived foods and is indigestible in the small intestine but can be a substrate for fermentation by the microbiota that primarily inhabits the lower gut. This can result in a rise in fermentation products such as short-chain fatty acids which are thought to confer several health benefits, including appetite control and suppression of food intake. Although increased fibre intake can be helpful, it is still a relatively underexploited dietary approach to tackle obesity. Therefore, foods containing fibre, that promote satiety and reduce energy intake, may be promising tools in weight management.

Further, food additives, such as artificial sweeteners or non-nutritive sweeteners, could influence the response to dietary fibre via the gut microbiota, which are tiny bacteria that live in the gut.  There is emerging evidence that some sweeteners could disturb the normal balance of the gut microbial ecosystem. Replacing sugar with non-nutritive sweeteners may inhibit the growth of bacteria for a healthy gut microbiome and may even promote harmful bacteria and/or metabolites. For humans to benefit from dietary fibre, fermentation is essential. This will not happen effectively if additives reduce the beneficial bacteria needed for this process. Furthermore, some non-nutritive sweeteners may prevent weight loss if microbiota disruption adversely affects satiety signalling from the gut. Indeed, reports suggest that some non-nutritive sweeteners are associated with weight gain and obesity as well as disrupted blood sugar control, thereby being potentially as harmful as the sugary drinks they replace.

In Scotland, there is a ‘fibre gap’, with the population consuming well below the recommended levels for good health. It is crucial to explore the reasons for inherently low fibre intake by considering the attitudes of Scottish consumers to dietary fibre and its link to health using a consumer survey approach. Furthermore, there is a need for a move away from a meat-based diet towards increased fibre intake for health reasons, as well as to transition towards a sustainable, environmentally friendly food supply. These issues appear to be being largely missed or ignored by consumers in Scotland.

The consumer has a right to know what is contained in the food they eat. There is significant risk in the food supply chain of fraud, where food is replaced by a cheaper or inferior alternative. The risks are particularly high for several food and drink products produced within Scotland that attract a premium because of their higher quality and consumer desirability (for example, whisky, beef and honey). It estimated that 4.4% of spirit sales in 2016 were lost to counterfeiting across the European Union. Given the premium nature and high demand for Scotch Whisky, the losses are likely to be larger. At the current rate, of £4.7 billion in exports, this equates to £207 million every year. Following the UK’s exit from the European Union and the need to develop more global food chains, the potential for food fraud has increased. There is a critical need to develop new methods to confirm the provenance of food substances across the food supply chain.

While DNA-based approaches are often used to assess food fraud, they are limited to foods that contain DNA of sufficient quality and quantity to allow polymerase chain reaction (PCR) based methods. Thus, DNA-based approaches are unsuitable for liquids, and there have also been recent concerns in processed foods that DNA may be too degraded to be reliably detected during PCR tests. Mass spectrometry metabolomics and proteomics workflows hold great promise for food authentication and understanding the provenance of a range of foods including meats, fish, honey and alcoholic drinks. Proteomics is the large-scale analysis of the protein complement of a biofluid, tissue, organism or food while metabolomics is the large-scale analysis of the small molecule composition of a biofluid, cell, tissue, organism or food. While most approaches of these two ‘omics’ have been applied to biomedical applications, there is increasing realisation that these approaches could be used in food science.