Unsafe food causes 1.52 million deaths globally, children under five most at risk, reveals study

Food poisoning has long been viewed as a temporary inconvenience- a few days of diarrhoea, stomach cramps, and recovery. A major new WHO-backed study published in The Lancet Global Health suggests it can be much more severe.

The study estimates that in 2012, contaminated food caused 866 million illnesses and 1.52 million deaths. What is particularly striking is that children aged less than five years face almost three times the risk of illness from unsafe food than older children and adults.

According to WHO, despite being just 9 percent of the global population, young children suffer nearly one-third of all cases of foodborne diseases, particularly diarrhoeal diseases, which can be deadly for this vulnerable age group. In addition, exposure to chemical hazards such as methylmercury and lead in food can harm the developing brain and cause lifelong neurological and developmental problems in children.

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The analysis includes 42 major foodborne hazards, including bacteria, viruses, parasites, and chemicals, across 194 countries from 2000 to 2021.

Not just childhood infections, unsafe food is said to cause heart disease, cancer, stroke, and intellectual disability. Unsafe food, researchers say, is responsible for 57.1 million disability-adjusted life years (DALYs), or years of healthy life lost due to illness. Putting this in perspective, the burden of disease caused by unsafe food, according to researchers, is comparable to that of major global killers like tuberculosis, HIV/AIDS, and malaria.

According to WHO, many of these illnesses could be prevented through measures such as improved water, sanitation, and hygiene; food safety practices such as pasteurisation; and access to healthcare for vulnerable populations.

“Food safety is not an abstract issue- it touches every meal, every family, every day. Unsafe food has always been a major public health concern, but until now we lacked the bigger picture of its staggering human and economic toll. These new estimates change that,” said Dr Tedros Adhanom Ghebreyesus, WHO Director-General. “For the first time, countries have their own data to see where the burden is highest. With that knowledge, governments can prioritise the actions needed to protect people’s health.”

Children bear a disproportionate burden

Children emerged as the biggest victims of unsafe food and carried a burden far greater than their share of the population. The study found that children under five years of age experienced foodborne illness rates that were 2.7 times higher than those seen in older children and adults. The DALY measure, which combines illness, disability, and premature death, was 4.3 times higher.

According to the researchers, food contaminated with pathogens such as rotavirus and non-typhoidal Salmonella continues to cause severe diarrhoeal disease, malnutrition, and death among young children. At the same time, exposure to toxic substances such as methylmercury can impair brain development, leaving lifelong effects on cognition and learning.

“Children under five are the worst affected by foodborne and waterborne illnesses because their immunity is still developing. Their bodies are still developing, so they can be more at risk of harm. They put their hands in their mouths more than adults do, so they are likely to ingest more,” said Dr Sivaranjani Santosh, a renowned paediatrician known for her work on wrong labelling, including that of ORS.

“Toddlers are particularly vulnerable because they cannot communicate their symptoms well. By the time parents realise they are sick, they may already be severely dehydrated or even in shock,” she added.

It's not just viruses; you have poison on the plate

The findings are particularly striking as they show a shift in what constitutes a foodborne disease. According to the study, while bacteria, viruses, and parasites remain major culprits, the largest share of deaths no longer comes from microbes. Instead, chemicals like arsenic and lead account for nearly three-quarters of all foodborne deaths. Researchers say 73 percent of deaths linked to contaminated food were caused by chemicals, although only 7 percent of illnesses were.

Most of these chemical-related deaths were linked to inorganic arsenic (42 percent) and lead (31 percent), largely because these exposures increase the risk of heart disease and cancer. Inorganic arsenic and lead are linked to more than 1 million deaths in a single year. Together, these two contaminants caused a greater disease burden than well-known pathogens such as Salmonella, Campylobacter, and cholera.

WHO says food can be contaminated with chemicals from natural sources and human activities. Once these substances have entered the food chain, they are often difficult or impossible to remove.

Geography matters

Yuki Minato, WHO technical officer for food safety and senior author of the study, said: “The data show that foodborne diseases are not only persistent but are being made worse by climate change, which increases contamination risks, and by antimicrobial resistance, which makes infections harder to treat.”

Children and people living in low-resource communities experience the greatest health burden, particularly in low- and middle-income countries. The African and South-East Asian regions together account for nearly three-quarters of all foodborne illnesses and 60 percent of global deaths.

Where does India stand?

A study showed that over a period of 10 years, from 2009 to 2018, a total of 2,688 foodborne disease outbreaks, resulting in 153,745 illnesses and 572 deaths, were reported to the Integrated Disease Surveillance Programme in India.

Around 172 outbreaks were due to simple household items such as roti, rice, khichdi, and dals; 94 from vegetables; 94 from contaminated sweets; 65 from contaminated milk and milk products; 58 from chicken and meat; and 25 from fish-based items.

Infectious biological agents are responsible for the overwhelming majority of foodborne illnesses in India.

“In Asia and Africa, a lack of food hygiene and access to safe drinking water remains a major driver of foodborne and waterborne diseases,” says Dr Santosh.

“Diarrhoea is still among the leading causes of death in children under five in India. Every year, we lose around one lakh or more children in this age group to diarrhoea alone. The introduction of the rotavirus vaccine has helped reduce rotavirus-related diarrhoea in India, but other foodborne and waterborne infections continue to be a major problem,” she added.

Regarding heavy metals and emerging concerns about arsenic, lead, and mercury exposure, Dr Santosh says India does not yet have sufficient data. “In India, bacterial, viral, and parasitic infections remain the dominant causes.”

“Some researchers believe heavy metal exposure could act as an epigenetic trigger in children who are already genetically susceptible to conditions such as autism, but at this stage these links remain theoretical and unproven.”