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Institute of Medicine (US). Improving Food Safety Through a One Health Approach: Workshop Summary. Washington (DC): National Academies Press (US); 2012.

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Improving Food Safety Through a One Health Approach: Workshop Summary.

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Food systems emerged with the dawn of civilization when agriculture, including the domestication of animals, set the stage for permanent settlements. Inhabitants could grow more crops and raise more animals than necessary to feed those who tended them. This changed human culture; unlike earlier hunter-gatherers, agriculturalists did not need to be in constant motion to find new sources of food. Cultivating grain allowed for drying and storage of some of the harvest for later consumption. Different grain cultures emerged in each of the cradles of civilization: maize in Mexico, rice in China, and wheat and barley in the Middle East. The ability to produce a surplus of grain also set the stage for the development of art, religion, and government.

Since agriculture began, food systems have constantly evolved, each change bringing new advantages and challenges and ever-greater diversity and complexity. This paper looks backward to the drivers of change and forward to the challenges faced by producers, consumers, and policy makers of tomorrow.

Changes Over Time and Space

The emergence of city-states has been a major driver of food system changes, bringing together large populations within defined boundaries and requiring complex governance to deliver sufficient quantities and quality of food. Advances in food storage, with sealed containers and curing methods, the use of animal transport, sailing ships, and trains to move larger volume than can be carried by individuals; trade in ingredients like salt as well as live animals and agricultural products; and increasing political and military conflict for resources all have been developments of the city-state. Extensive trading routes have existed for salt, spices, tea, and pepper for thousands of years.

The Iron Age and the Roman Empire brought expanding empires and the beginning of global food systems, including regional specialization in products traded throughout empires. Food systems began to be organized on a grand scale to feed larger cities and fuel local economies. Trade networks for grain, nuts, oils, fruit, and wine developed using both road systems and sailing routes. Standardized weights and measures were established along with the expansion of money and accounting.

The Middle Ages saw the emergence of the merchant class and banknotes. Prior to the Middle Ages, selling was considered a task for one of the lower classes of civilization, if not a sin. The equestrii in Roman times did the trading, not the citizens of Rome. The Middle Ages also saw banknotes replacing coinage, first with the Song dynasty in China and then later in Europe around 1661. As a wealthy class emerged, they became more sophisticated in their food preferences. The resulting demand of consumers began to affect trade in addition to supply.

Science and technology represent another major driver, changing the way that food is grown, processed, preserved, and transported. The Industrial Age brought a transition from manual labor and draft animal–based economies to machines. Further increases in agricultural productivity brought about by technology such as the seed drill, the iron plow, and the threshing machine freed up labor for the factories in the 1700s. The Industrial Revolution also created per-capita income growth. The emerging middle class had discretionary income to spend on its food preferences. Transportation breakthroughs were ushered in during the industrial age: canal systems, improved roadways, steam engines used for traction, railroads, and steamships. The Erie Canal, as an example, connected the Great Lakes and the northeastern United States with 363 miles of inland waterways by 1825.

Food preservation, important to both storage and transport of food, also changed over time. Drying was one of the early food preservation methods, certainly known in ancient times. Fermentation also was an early method of food preservation, with pasteurization applied to wine in China as early as 1117. Salting of food has been used for at least 500 years, beginning when the fishing fleets from Europe used drying and salting to store fish caught in Newfoundland and the Grand Banks in order to get them back to consumers in Europe.

Two preservation methods, canning and freezing, allowed food to be stored and transported in an almost-fresh state. Canning grew out of military research in 1810. Ice storage was developed in northern climates where ice could be cut from lakes in the winter for use later in the year. Commercial refrigeration followed in the 1800s. The first refrigerated ship, the SS Dunedin in 1882, revolutionized the meat and dairy industries in Australia and New Zealand. Refrigerated and frozen food products now could be traded globally.

The 20th century saw intensification of agricultural production with mechanization of planting and harvesting, selective breeding of animals and plants, and more attention to animal nutrition and feed input costs. Increased scale of production drove down the per-unit cost of products and fostered greater specialization in food systems. Advances in plant and animal disease control also helped, such as the movement of pigs and poultry indoors to decrease disease exposure and to enhance efficiency by controlling the environment.

Colonization and war have been important political influences on food systems, the first creating distributed ownership of food systems and the second highlighting a need for global agreements. Colonialism allowed for population growth of the industrialized countries when there were limited domestic opportunities to create employment or to grow food. Settler colonies captured market opportunities for the colonizing country's exports and provided import sources for raw materials, including food and food ingredients.

Trade underwent dramatic changes in the 20th century as a result of the two world wars. The war-associated food shortages, economic crises, and disease spread set the stage for global trade agreements and organizations designed to address global public good issues. The 1947 General Agreement on Tariffs and Trade was created to reduce tariff-based trade barriers and to prevent the downward spiral of world trade seen in the Great Depression from 1929 to 1933. Monthly trade dropped from $3.0 billion in January 1929 to $0.9 billion in March 1933 as protectionist measures reduced trade worldwide (Personal communication, Christiane Wolff, World Trade Organization, March 2012).

Supply-driven to demand-driven Until the 20th century many countries had supply-driven economies, where policies favored increased agricultural production to ensure adequate domestic supplies of basic feedstuffs. Increasing the supply and reducing the costs of food were politically popular national priorities. Food self-sufficiency was a powerful motivation, especially for countries that had experienced food shortages in the past. Countries that exceeded domestic demand used export markets and food aid programs to deal with the excess.

Rising discretionary incomes in Europe and North America in the 20th century impacted food demand and global food trade. Rising consumer demand for chicken drove the development of the broiler industry, but, as marketing moved from whole birds to parts such as leg quarters or breasts, demand disequilibrium resulted. For example, many Americans prefer white meat and do not eat chicken feet, while in other parts of the world people prefer dark meat and consider chicken feet a delicacy. Global food trade provided an opportunity to sell the parts of animals for which there is little or no domestic demand. One reason that the developed world enjoys relatively inexpensive food is the ability to market commodities and specialized products worldwide.

Food systems are dynamic and ever changing in response to natural forces (e.g., weather), demographics (e.g., emergence of megacities), economics (e.g., currency values), technological advances in processing (e.g., high pressure pasteurization), entrepreneurism (e.g., development and marketing of new products), and consumer preferences (e.g., locavores). Every country in the world produces some of its own food and trades food. As a result of these constant changes, food systems are increasingly complex, as adding to the challenge of assuring global food safety.

The Complexity of Current Global Food Systems and Implications for Food Safety

Today's food systems are diverse and complex, involving everything from subsistence farming to multinational food companies. Everyone eats; therefore, everyone relies on food systems, local and global. The movement of food and food ingredients in food systems includes animals and animal products, plants and plant products, minerals, and vitamins. The classic cheeseburger provides an excellent example of the complexity of today's supply chain. Researchers at the University of Minnesota mapped the global supply chain of the cheeseburger working with a large quick-service restaurant chain, Figures A5-1, A5-2, and A5-3 tell the story. Figure A5-1 demonstrates graphically the movement of different commodities from the farm through processing to the restaurant. Figure A5-2 lists all the ingredients found in this company's cheeseburgers and Figure A5-3 provides an idea of the variety of companies supplying key ingredients like vinegar, garlic powder, tomatoes, beef, and wheat gluten. Each cheeseburger includes more than 50 ingredients sourced from countries in every continent of the world except the Arctic.

A flow diagram showing the components in of a generic "megaburger" from farm to table


Global supply chain complexity. Movement of commodities. SOURCE: Shaun Kennedy, Director, National Center for Food Protection and Defense, University of Minnesota.

A list of the components in each of the ingredients in a generic "megaburger"


Global supply chain complexity. Ingredient list. SOURCE: Shaun Kennedy, Director, National Center for Food Protection and Defense, University of Minnesota.

A listing of the countries of origin of ingredients in the components used to make a
generic "megaburger"


Globalizing the cheeseburger. SOURCE: Shaun Kennedy, Director, National Center for Food Protection and Defense, University of Minnesota.

Food processing supplies also move globally and include processing equipment, packaging, and chemicals such as disinfectants and preservatives. Agricultural inputs move too, from feed to fertilizer, to vaccines and pharmaceuticals, to planting and harvesting equipment. As agricultural commodities are combined with other food ingredients to create processed foods, individual food items commonly include ingredients from multiple countries. The increasing consumer demand for “ready-to-eat” foods has fueled the growth of quick service restaurants and fully cooked, frozen dishes that only require reheating, further expanding supply chains. Government regulatory systems and private-sector initiatives are part of food systems, as are educational efforts and consumer actions.

Food systems are integrally related to food safety. Contamination can occur at any point in the food system, and prevention and control strategies can be implemented at any point. The scale and complexities of today's food systems contribute to the likelihood and magnitude of food-borne illness (Ercsey-Ravasz et al., 2012). The more complex, the more opportunities for things to go wrong; the larger the scale, the more people are potentially affected.

Complex food systems each involve interconnected subsystems that, taken together, exhibit properties that are not predictable by the properties of the individual subsystems or their parts. Food systems can be called complex adaptive systems. These have no boundaries; individual actions affect the food systems by what individuals produce and what they purchase. Complex adaptive systems have a memory. While food systems change over time, present behavior is affected by prior behavior. Food systems are nonlinear. A small perturbation in some part of the system may have a large effect, a proportional effect, or no effect. And the relationships of this system of systems have feedback loops. The adaptiveness and nonlinearity of food systems mean that food safety problems are also nonlinear; they can be anticipated but are hard to predict with accuracy or precision.

Feeding the world requires a multitude of systems. Each system is dynamic and the food systems are interdependent; there is no one best system that meets all needs. However, every success in improving the food system perturbs the whole system of systems and changes the nature of the food safety problems.

Lessons for the Future

Looking at existing global food systems and predicated demands for food, we can reasonably speculate the following over the next 10 to 20 years:

  1. Food systems will continue to change, although with additional drivers. The drivers of urbanization, production and processing technology, transport technology, and political forces that have played a large part in shaping current food systems will continue to be relevant. Newer drivers playing an increasingly important part are a real prospect of a global population of 10 billion, aging populations changing the production and consumption base, climate change leading to constraints on water supplies, severe constraints on nonrenewable energy, and communication technology.
  2. Food systems will continue to shift from being supply driven to being demand driven. The global quick service restaurant chains like McDonalds and big-box retailers like Walmart have had an enormous impact on food systems. Consumer groups demanding safety, fair trade, “green” production, and animal welfare-related changes in production practices put pressure on policy makers and retailers. The large processors are putting pressure on the primary producers of plants and animals for assurances on source, on identity preservation, on means of production, and on characteristics like animal welfare and labor standards.
  3. Increasing prominence of private standards. Successful completion of the Uruguay Round of the multinational trade negotions under the framework of the General Agreement on Tariffs and Trade included approval of the Sanitary and Phytosanitary Agreement (SPS) in 1995 under a new organization, the World Trade Organization (WTO). The SPS established a framework for international standards for trade in animals, plants, and the products derived from them including food. More recently, coalitions of companies are forming to standardize specifications for food products, basically saying, “we can't wait for the slow process of international standards organizations.” An example is the Global Food Safety Initiative, a nonprofit organization that benchmarks guidelines established by food processors, retail, and food service against the international standards recognized by WTO. Food safety standards used by the large companies who target premium market niches are often above and ahead of the minimum demanded by legislation.
  4. Panarchy. The term “panarchy” is used in systems theory to describe systems interlinked in continual adaptive cycles of growth, restructuring, and renewal (Gunderson and Holling, 2001). The increased growth in connectedness and efficiency results in a lack of redundancy and at the same time makes individual food systems less resilient, more sensitive to stress, and therefore more susceptible to collapse. If subsystems within complex food systems collapse, the result is systems with greater resiliency that have fewer connections and less efficiency. And the cycle starts again.
    Food systems have demonstrated adaptive cycles as they have evolved. Many current food systems have evolved to a point where they are both complex and sensitive to stress, and the results of a collapse in a subsystem can be wide-reaching. For example, the concentration of production of an ingredient like a vitamin in a single company or country may be the most efficient approach, but if a production problem ensues or a disaster disrupts this supply chain, then all food processors using this vitamin as a food ingredient are affected. They must either remove the vitamin from their recipes or stop production because of lack of supply. Another example is the proliferation of “just-in-time” supply chains. Instead of stockpiling food supplies in warehouses, many large food retailers and food services have worked with food manufacturers to establish these supply chains. Real-time data on usage and inventories are provided directly to the supplier on a regular basis to allow for customized shipments of only those food products needed. If the supply chain is disrupted, there is very little food in reserve. Many cities have less than 2 days' supply of perishable food like milk and eggs on the shelves at retail outlets. People in countries where systems regularly collapse have coping strategies: they store food, water, and alternative energy at home. Many of those in large modern cities do not. The urban poor have neither the finances nor the storage facilities to store reserves of food.
  5. Culture clash. Disconnects exist between origination and destination countries because of differences in their cultures and differing levels of economic development. While developed countries have emphasized the importance of food safety and quality, less-developed countries may focus on the opportunity for exports to generate foreign currency reserves. The recent melamine incidents demonstrate economic adulteration in order to achieve greater profit in domestic and international markets.

What Do One Health Approaches Have to Offer Food Safety in the Context of Food Systems?

Food safety is a “wicked problem.” We cannot completely understand the challenge; it is too complex. And yet food safety is compelling: people are getting sick and dying every day as a result of unsafe food and water. We must take action, and we recognize that every action we take perturbs the very food systems we are working to improve. The so-called wicked problem reflects the condition of a complex adaptive system.

If One Health is taken to imply holistic and multidisciplinary approaches to complex challenges (e.g., wicked problems), then a One Health approach offers the possibility of new perspectives on safety in food systems and new ways of working. It implies systems thinking, shared leadership, a holistic view, and a multifaceted approach.

Is this back to the future? The World Health Organization (WHO) definition of health in 1948 was quite broad: “Health is a state of complete physical, social, and mental well-being, and not merely the absence of disease or infirmity.” However, the public health implementation of food safety focus often is limited to prevention and response to infectious diseases rather than a more holistic approach to food safety as an element of food security (availability, access, and nutrition as well as safety). More recently, the Food and Agriculture Organization and the WHO have developed a much broader definition of food safety: “All the conditions and measures necessary during production, processing, storage, distribution, and preparation of food to ensure that it is safe, sound, wholesome, and fit for human consumption.”

Successfully applying One Health approaches to food safety requires a sound understanding of the dynamics of food systems. Food safety must be addressed in a systemic manner rather than an ad hoc approach driven by reaction to crises. These One Health approaches have implications for what we record, measure, and analyze in food systems and how we share information about potential food safety problems as well as existing crises.

One Health approaches also require a new leadership model that is adaptive and shared, matching the adaptive nature of food systems and the many ways they are controlled and influenced. Five skill sets for adaptive leaders were identified by a small international working group at a session in Bellagio, Italy, sponsored by the Rockefeller Foundation: communications; getting things done and accomplishing change; working across boundaries, whether disciplinary, sectoral, or political; influence; and vision and strategy.

Applying these skills sets encourages a move from finger-pointing to shared leadership. It provides space to accept the fact that food-borne disease happens and will happen. Food safety programs are not always somebody's fault. After all, “safe food” is an oxymoron. All food has risks and yet “safe” implies the absence of risk. Food systems can either contribute to the risks or be designed to help manage the risks. The very complexity of food systems also means that an infinite number of risk-management strategies are available, if we are only creative enough.

Incremental progress on complex food safety problems may also require a new model of partnership that engages producers and the food industry along with government. We do not have an ideal model for partnership or shared leadership, but several initiatives in fisheries and foods are trying to find or build models, and so are others outside of the food sector. A new partnership model would include a value proposition to engage industry (examples are beginning to emerge around agriculture and environment, where there is no alternative but for government and the private sector to work together) and a more flexible and realistic regulatory system. The idea of zero tolerance makes no scientific sense (zero risk is unachievable) and contributes to the very high levels of waste in U.S. food supply chains (e.g., supermarkets in the United Kingdom are moving to changes in the “use by” label to provide more flexibility in home-freezing, which is anticipated to reduce waste in kitchens with no reduction in food safety).

What Comes Next?

We have proposed a One Health approach that would match the complex, adaptive problems of food safety with shared, adaptive, and holistic problem solving that considers the entire food system. However, an approach is of little use while it remains on paper. The next challenge is to find a complex, subtle, pervasive, and wide-ranging food safety problem that will require adaptive leadership, partnerships, and a wide scope of action—the problem of mycotoxins is excellent example—and put the food systems community to work on it.


  • Ercsey-Ravasz M, Toroczkai Z, Lakner Z, Baranyi J. Complexity of the International Agro-Food Trade Network and Its Impact on Food Safety. PLoS ONE. 2012;7(5):e37810. [PMC free article: PMC3365103] [PubMed: 22701535]
  • Gunderson L, Holling CS. Panarchy: Understanding transformations in systems of humans and nature. Washington, DC: Island Press; 2001.

Global Initiative for Food Systems Leadership.


College of Veterinary Medicine and School of Public Health University of Minnesota.

Copyright © 2012, National Academy of Sciences.
Bookshelf ID: NBK114491


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