As the web of global food trade becomes more and more complex, humans become increasingly vulnerable to prolonged foodborne illness outbreaks, says a team of international researchers. The interconnectedness of the world’s food supply is putting global food safety in jeopardy, according to a study published last month in PLoS ONE, because it allows for contaminated food to be distributed far and wide, and makes it difficult – if not impossible – for health officials to trace ingredients back to their origins. In 2008 the value of the global food trade was estimated at 1060 billion U.S. dollars. The data on international trade routes is so vast and intricate that it required a team of scientists who specialize in network analysis to map it out. Zoltan Toroczkai, a physics professor at Notre Dame University and co-author of the paper, says he was shocked when he first looked at the United Nations’ food trade database. “You see these kinds of complex maps in the cell biological system when you look at the cell’s metabolic network, Toroczkai explained. [The global food trade map] looks eerily similar.” Indeed to the untrained eye, the diagram the team created looks like a complicated molecular structure or a chaotic mind map. One thing is clear though: our food is making moves. Lots of them. “Less and less food is actually consumed locally, but gets into trade and is transported somewhere else either as ingredients or sellable foods,” said Toroczkai in an interview with Food Safety News. This means that countries that may be physically far from one another are sitting down to the same virtual table when they eat. “A food item you’re eating could have ingredients from all over the world,” explains Toroczkai, “and that increases your vulnerability, especially if you are part of the core countries that participate in extensive trade.” The density of the global food web “guarantees that if there’s an outbreak it will quickly reach any part of the network,” says Toroczkai, “and it will also be very difficult for you to trace where the food is coming from because it gets mixed and sent on many, many routes.” And, he says, “the more time you’re delayed looking for the source, the more people can get sick or die in the meantime.” The European E. coli O104:H4 outbreak in the spring of 2011 provides a painful example of the dangers of slow traceback. After authorities determined on June 13 that sprouts from a certain farm in Northern Germany were the likely outbreak vehicle, it would be 18 more days until seeds exported from Egypt would be identified as the original source of the bacteria and withdrawn from the market. It is possible that the outbreak, which sickened over 4,000 people and killed at least 50, may have been more devastating because of this delay. The European outbreak “illustrated the importance of prompt tracing of the origin of specific food ingredients,” the paper points out. So what can be done to make sure ingredients can’t shed their identity after reaching another country like a fugitive on the run? The answer, as in any detective case, is to gather more information. “What’s missing as information that should be recorded and available is what happens with ingredients after they enter the country,” says Toroczkai. Products are usually recorded in a log when they enter the country, but after that the trail tends to go cold, he explains. That’s why an ingredient and its origin should be marked on every product it becomes a part of, he says. Records marking where the food came from and where it’s going should be made every time it changes hands. Such information will also be essential for researchers looking at where food chains are most vulnerable to contamination, what types of products are redistributed most often and other questions whose answers are key to protecting public health. “Part of the conclusion of this paper was that we need to go into detail if we want to improve food safety and transport,” says Toroczkai. “The data that we have from the United Nations only gives us the aggregate of food traded between countries.” Getting all 207 countries to maintain a database of food redistribution is a titanic task. The best policy, say the authors, will be to get countries through which the most food travels on board. The study identifies the 7 countries that account for the bulk of international food trade: the United States, the Netherlands, Germany, France, Great Britain, China and Italy. Each of these countries trade with over 77% of the world’s 207 nations, meaning that food from at least 150 other countries is flowing through each of these 7 throughout the year. “The largest fraction of the GDP per person for food trade is coming from the Netherlands,” says Toroczkai. “Almost all of it goes through Rotterdam. In principle one could do an excellent job there of tracking what ingredients came from where and where they are repackaged and sent from the Netherlands.” “We would like to consider this paper as a call for better data management on where food gets sent and how it’s being processed,” Toroczkai says. Whatever the solution, it must be achieved through a unified global effort, he notes. “More and more people are becoming aware that this is an issue that needs to be repaired,” says Toroczkai. “But it has to be a coordinated effort…This has to be done on an international level.”