Some 600 million people get sick from eating contaminated food each year, and around 420,000 die, the World Health Organization said Thursday, adding that young children account for nearly one third of those deaths.
In its first-ever estimate of the impact of foodborne diseases, the UN health agency found that almost one in 10 people globally get sick each year from food contaminated with a range of bacteria, viruses, parasites, toxins and chemicals.
Kazuaki Miyagishima, head of WHO's food safety division, stressed the importance of getting clear data on the problem.
"Until now, we have been combating an invisible enemy, an invisible ghost," he told reporters in Geneva, adding that he hoped that quantifying the toll of contaminated food would help mobilize countries to significantly boost food safety.
The report, which is based on analysis of data up to 2010, identified 31 different agents contaminating food and making hundreds of millions of people either acutely ill or injecting them with serious illnesses like cancer that may not surface until years later.
In addition to killing nearly half a million people each year, foodborne diseases are taking a significant toll on the quality of life of those who survive, the report said.
Each year, the global population as a whole loses a full 33 million so-called Disability-Adjusted Life Years (DALYs), or healthy years of life, it said.
'Very conservative' numbers
Miyagishima said the numbers were "very conservative," representing the "minimum damage caused to humanity by contaminated foods."
Since foodborne pathogens take advantage of weak immune systems, young children are particularly at risk.
Children under the age of five make up only nine percent of the global population but account for nearly 40 percent of all illnesses linked to eating unsafe food and 30 percent -- 125,000 -- of all related deaths, the report said.
Foodborne diseases can cause short-term, albeit violent, symptoms like vomiting and diarrhoea, usually referred to as food poisoning, but can also cause long-term illnesses like cancer, kidney or liver failure, brain and neural disorders, it said.
Diarrhoeal diseases, often caused by eating raw or undercooked meat, eggs and dairy products contaminated with salmonella, E.coli or campylobacter bacteria, or the norovirus stomach bug, are by far responsible for most foodborne diseases.
Some 550 million people fall sick with food-related diarrhoea diseases each year, and 230,000 of them die, including 96,000 children under the age of five, the report showed.
It also listed parasites like the Taenia Solium tapeworm and aflatoxin, which is produced by mould on grain that is stored inappropriately and which has been linked to cancer in the liver and kidneys, among the major culprits.
While some diseases, like those caused by salmonella, can wreak havoc worldwide, many food contaminants are far more common in poorer countries, where people are more likely to prepare food with unsafe water, and where food production and storage is more likely to be inadequate.
Lower levels of literacy and education, as well as lax or poorly implemented food safety laws compound the problem.
Africa and Southeast Asia are the hardest-hit regions, together accounting for 312,000 deaths related to contaminated food each year, compared to just 5,000 deaths in Europe and 9,000 deaths in the Americas, where food safety laws are stronger.
Arie Hendrik Havelaar, who heads WHO's foodborne disease burden epidemiology reference group, said the jarring differences showed countries could choose to make the food we eat safer.
"A large part of these foodborne diseases are preventable," he told reporters.