Is Eating Raw Meat Dangerous? Understand the Health Risks

People fancying a culinary adventure are sometimes tempted by the taboo of eating raw meat in dishes like “pierced body” (sashimi) or “cannibal sandwiches” (steak tartare on bread). But eating raw meat can be deadly, and not just for whoever winds up on the plate. 

Can Humans Eat Raw Meat?

Eating raw meat may be a common practice around the world, from Italian carpaccio to Peruvian ceviche, but that doesn’t make it safe. Eating raw meat raises the risk of a range of health problems.

What Happens if You Eat Raw Meat?

Foodborne Illness

Every living animal, including you, is host to a microscopic ecosystem of bacteria, fungi, and viruses. Most of these microorganisms are killed when meat is cooked. But when left uncooked, meat becomes fertile ground for these and other germs within hours of death. This is often referred to as “spoilage,” but spoilage is just the beginning of decomposition. Foodborne illness, or food poisoning, occurs when people eat meat that is still alive with bacteria, viruses, parasites, and other pathogens. Though quite common, food poisoning is also quite deadly, killing roughly half a million people around the world each year. 

Trichinellosis (aka Trichinosis)

Trichinella spiralis, a type of roundworm, is an infectious parasite that can thrive in most warm-blooded animals, including pigs, boars, bears, horses, and dogs. When a person eats uncooked or undercooked meat from an infected animal, roundworm larvae survive and latch onto the inside of the small intestine. Once mature, roundworms spawn new larvae that infiltrate cells and tissues, including muscle, which is essentially raw meat. As the parasites colonize the newfound human host, trichinosis induces diarrhea, abdominal pain, nausea, vomiting, muscle pain, fever, headache, and swelling of the eyelids and face. 

E. coli

Escherichia coli (E. coli) bacteria inhabit the intestines of healthy animals, including humans. While most strains of E. coli are harmless, variants common in cattle, such as E. coli O157:H7, produce toxins that can cause severe illness. These toxic germs find their way into produce through manure used in fertilizer and fecal runoff that contaminates water sources. When cattle are slaughtered and processed, meat can be exposed to the bacteria simply by coming into contact with the animals’ own intestines. In humans, E. coli O157:H7 causes bloody diarrhea, abdominal pain, nausea, and vomiting. Infected humans can further spread the germs by not washing, or inadequately washing, their hands after using the bathroom. Diarrheal infection from E. coli can cause Hemolytic Uremic Syndrome (HUS), a serious and sometimes fatal disease affecting the blood and kidneys. 

Mad Cow Disease

“Mad cow disease,” formally known as bovine spongiform encephalopathy (BSE), is a fatal brain disorder that affects cattle who are fed other cattle, and people who eat those cattle. The disease erupted into a pandemic in the 1990s as the result of U.K. dairy and beef farmers feeding livestock a low-cost protein, known as a meat-and-bone meal (MBM), made from slaughterhouse scraps—including the remains of other cattle. 

While mad cow might be viewed as a pandemic of the past, the first large-scale outbreak likely isn’t over. BSE has an extraordinarily long incubation period and can take decades, even 50 years or more, to emerge in humans. According to studies in the U.S. and Japan, Creutzfeldt-Jakob disease, the disease that can be caused in humans by BSE-infected meat, is on the rise. While a range of explanations for these rises have been offered, none are conclusive. In more recent years, there have been at least 70 new cases of cows diagnosed with BSE in Brazil (the world’s largest beef producer), the U.S., Canada, Scotland, and across the rest of Europe. While beef producers might insist these are isolated cases, BSE can lie dormant in cattle for up to six years. Most farmed cattle are killed long before they ever reach the age of six, meaning that any other infected animals could have already been killed, processed, and sold to consumers. 

Could Humans Eat Raw Meat in the Past?

Homo antecessor, seen by some researchers as the last common ancestor of both Neanderthals and us Homo sapiens, did eat raw meat, according to dental plaque analysis. Forensic evidence also reveals that this primitive ancestor was a cannibal who even preyed on infants and children. This was 1.2 million years ago and since then, humans have evolved significantly. Once our ancestors discovered how to control fire, humans became the first and only species to cook food. The development of cooking allowed our ancestors to evolve their diets to eat far more energy-dense roots, vegetables, nuts, and seeds. Eating more starch altered the types of bacteria in our ancestors’ mouths. And eating more carbohydrates, specifically glucose, fueled brain growth, allowing for the evolution of modern humans. 

Why Can Animals Eat Raw Meat but Not Humans?

Just as the advent of cooking shaped humans, other circumstances and events shaped other animals into just that: other animals. 

1. They Can Digest Meat Better

Obligate carnivores, like lions and house cats, lack the enzymes needed to break plants down into essential nutrients but developed highly acidic stomachs and specialized enzymes to efficiently digest muscle, blood, skin, cartilage, and even bone.

2. They Are Better Adapted to Fight Meat-Borne Diseases

Cats and other carnivores also evolved well-adapted immune systems to fight and destroy the very same pathogens that would make us sick if we ate their diet. 

3. They Eat Fresher Meat

Because most animals eat fresh meat, their risk of being infected by bacteria and parasites is lower than if they ate meat that had spent more time spoiling.

4. They Can Smell Bad Meat

With a better sense of smell than humans, carnivores are more able to sense which bits of meat might pose a danger to them.

What You Can Do

Not eating raw meat is an incredibly easy way to avoid food poisoning, intestinal parasites, and toxic germs. But why stop there? Giving up meat entirely could also reduce your risk of heart disease, stroke, and cancer. Recent studies show that entirely plant-based diets can even extend our lives by a decade or more. Given the benefits to personal and public health, the health of the planet, and the lives of animals, perhaps we should all ditch the meat-heavy diets that increase our risk of disease and eat like we believe in science.