Here’s Why Sushi Made With Raw Fish Is Safe To Eat But Raw Meat Is Not

Have you ever wondered why people eat sushi without a second thought but balk at the idea of undercooked chicken? Or why people love a steak so rare it’s practically mooing but a pork chop needs to be cooked until it’s essentially a meat frisbee? Well, you’re not alone—we, too, have wondered the same thing about raw fish vs. raw meat. And essentially the answer comes alllll the way down to the tiniest of reasons: bacteria.

This might gross you out, but the kinds of parasites and bacteria crawling around raw land animals are far more toxic to humans than those found in fish. Salmonella, E.coli, worms and even the virus hepatitis E can all inhabit raw meat.

sushi photo
Getty Images | Sean Gallup

“Perhaps it’s because our bodies are more closely related to land animals than to those of fish,” Dr. Robert Tauxe, deputy director of the Division of Foodborne, Waterborne and Environmental Diseases within the Centers for Disease Control and Prevention (CDC), said in an interview with TIME.

The problematic bacteria live in the guts of the animals we consume, and meat can become contaminated if the bacteria-carrying areas of the animals are nicked in the butchering process. So, in ground beef, for example, it’s not that the muscle that’s ground into meat carries its own bacteria. Instead, it’s possible that bacteria ended up there while being processed.

According to Dr. Eugene Muller, a microbiologist at Framingham State University in Massachusetts, it’s the outside surface of the meat, not the inside that is cause for concern.

“Anything harmful lives on the surface of the meat, not inside the muscle,” Muller says. “So if you like your steak very rare, just searing the outside will likely kill anything harmful.”

STEAK photo
Getty Images | Justin Sullivan

Additionally, sushi isn’t usually ground up or mixed with other kinds of fish, as land animals commonly are and which can make contamination more likely. Raw fish you eat at a sushi restaurant is also typically caught in colder waters and frozen before you eat it. The freezing is important, Tauxe says, because it kills any potential worms or other parasites that might be in the fish. When it comes to meat, freezing doesn’t kill E. coli or any of the other microorganisms that can make you sick—but the high heats used in cooking will.

This isn’t to say that raw fish is completely without risk, however. Uncooked fish could still be carrying microbes or parasite that can lead to food poisoning or infection, so it’s important to know how to choose raw fish wisely. If you’re determined to make your own ceviche, for instance, make sure you shop at a high-quality fishmonger who knows that you’re planning on serving raw or cured fish. Otherwise, anything that has been flash-frozen is the safest.