Access to safe and nutritious food is essential for good health, yet contaminated food remains a major cause of illness worldwide.

Harmful bacteria, viruses, parasites, and chemicals in food can cause more than 200 diseases, affecting millions of people every year, especially young children, older adults, and those with weaker immune systems.

Why Unsafe Food Is a Serious Risk

Food becomes unsafe when it is contaminated by germs or harmful substances at any point during production, storage, transport, or preparation. This can lead to illnesses ranging from mild stomach upset to long-term disease or even death.

Unsafe food also creates a cycle of illness and poor nutrition, particularly in vulnerable groups such as infants and children, where repeated illness can weaken growth and development.

Common Germs That Cause Illness

Many foodborne illnesses are caused by bacteria found in everyday foods. Germs such as Campylobacter, E. coli, and Shigella are linked to contaminated poultry, raw milk, undercooked meat, and unwashed fruits and vegetables. These infections often cause fever, vomiting, stomach pain, and diarrhea.

Some infections can be more dangerous. Listeria, found in unpasteurized dairy and ready-to-eat foods, can be deadly for newborns and harmful during pregnancy. Cholera bacteria, often spread through contaminated water or seafood, can cause severe dehydration and death if untreated.

Viruses also spread through food. Norovirus is a common cause of outbreaks, while Hepatitis A can spread through contaminated seafood and produce. Hepatitis E is often linked to undercooked pork products.

Foodborne Parasites and Long-Term Illness

Some parasites in food can cause serious health problems that develop slowly over time.

For example, certain infections can lead to epilepsy, liver and bile duct cancer, or serious complications during pregnancy. One parasite, Toxoplasma, can harm unborn babies, while another, linked to Chagas disease, can be passed through contaminated food and cause severe illness.

Harmful Chemicals in Food

Food can also contain harmful chemicals such as arsenic, lead, mercury, and cadmium. These can enter food through polluted soil, water, or unsafe production methods.

Exposure to these substances is linked to serious health problems, including heart disease, cancer, kidney disease, and brain damage in children. In 2021 alone, exposure to arsenic and lead in food was linked to over 1 million heart-related deaths and 124,000 cancer deaths worldwide.

Some natural toxins in food, such as those found in poorly stored grains, nuts, and crops, can also cause long-term illness, including liver cancer and poor child growth.

The Global Impact of Foodborne Disease

Food safety remains a major global challenge. In 2021, unsafe food caused an estimated 866 million illnesses and 1.52 million deaths worldwide, according to the World Health Organization.

The burden is highest in poorer countries, and young children are among the most affected. The global cost of foodborne disease is also huge, reaching around $310 billion each year in medical costs and lost productivity.

A Shared Responsibility

Experts warn that climate change is making food safety risks worse by affecting temperatures, rainfall, and the spread of germs in food and water. Because food is now traded globally, a problem in one place can quickly affect many countries.

To reduce risks, food safety must be a shared effort. Governments need to set strong rules, food producers must follow safe practices, and consumers must handle and store food properly. Together, these steps help ensure safer food “from farm to table.”