The Health Risks of These 4 Raw Foods Aren't What You'd Expect

You probably know that eating raw foods can sometimes be risky. But those risks aren’t necessarily what you’d think. For example, did you know that it isn’t (just) the uncooked eggs that can make you sick from eating raw cookie dough? Or that finding worms in sushi isn’t usually dangerous (despite what social media may say)?  

Here are some of the raw foods likely to tempt you and just how dangerous they are to your health.  

Raw fish

You might have seen reports of parasitic worms crawling out of sushi circulating on the internet and thought, “Should I be laying off the sashimi?”

Well, yes, fish can have worms in their flesh if they consume marine life infected with parasitic larvae. But the good news is that parasites are easy to kill.  

“There are two strategies that work really well,” says Dr. Christopher Sanford, a family medicine physician at UW Medicine and co-host of the travel health podcast “Germ and Worm”  with fellow UW Medicine physician Dr. Paul Pottinger. “You can either cook the fish, or you can flash freeze it.”

Because of the latter strategy, he doesn’t worry about sushi — quite the opposite: “My favorite cuisine in the world is sushi; I eat sushi right and left,” he says. “The reason I feel good about sushi is that by U.S. Food and Drug Administration law, you can’t serve fish in the U.S. at a restaurant if it’s raw unless it’s flash frozen.”

Flash freezing entails keeping the fish at temperatures of 4 degrees below zero for seven days, or at a much colder temperature for a shorter amount of time in an industrial freezer. Parasites can’t survive those conditions. If you’re making your own sushi, check with the store or market you buy your fish from to see if it’s been flash frozen (if it’s fresh, it might not be). If not, or if you caught it yourself, you can flash freeze it in your own freezer if it can get cold enough and you have a week.  

If you do get a parasitic worm, you might pass it without any symptoms or you could experience GI distress or even an allergic reaction. Your doctor might then order a fecal test which can determine if you have a parasite. If you are immunocompromised, your risk of a severe infection is higher, so factor that into your risk assessment.  

Of course, you could also get sick from bacteria or viruses if they were present in the water the fish was swimming in or during transport or processing — indeed, the Centers for Disease Control and Prevention investigated a multi-state salmonella outbreak linked to raw salmon in 2022. (No the bacteria’s name doesn’t come from the fish, it was named after the person who discovered it, Daniel Salmon.) The only way to kill bacteria is by cooking fish to an internal temperature of 145 degrees. 

Raw milk

Raw milk has been touted as having myriad nutrients and health benefits that normal milk loses when it’s pasteurized. But is that actually true?

The pasteurization process involves briefly heating the milk to high enough temperatures to kill bacteria and other pathogens that might contaminate it, then quickly cooling it back down. According to the CDC, there is no evidence the process affects the milk’s nutritional value.

“The reason pasteurization was developed is because it’s really effective at keeping people from getting sick,” says Emily Hovis, an assistant teaching professor at the University of Washington School of Public Health and former food safety specialist for the Washington State Department of Health.

When she worked for the health department, she heard a lot about raw milk.  

“Raw milk folk are super passionate,” says Hovis. “I also live in a rural community and I talk to folks about raw milk, because if you grew up drinking raw milk on a farm, you probably don't think it's that risky. But a lot of the outbreaks I investigated were associated with raw milk.”

Everything from salmonella to listeria, to campylobacter and E. coli, can infect milk through dirt or mud that gets on a cow’s udder or the hands of the person milking it. This year, tests detected bird flu virus in retail raw milk samples. If it’s not pasteurized, those pathogens will go straight into your body when you drink it. The risk of severe infection is especially high for children under 5, adults over 65, and people who are pregnant or have weakened immune systems. 

Raw cookie dough

If you are a cookie dough fan, you probably know that the raw egg in it comes with the risk of getting salmonella. But did you know there’s another culprit? Flour. That’s right, flour isn’t pasteurized or treated for pathogens (no, bleaching doesn’t help), since it’s meant to be cooked. Bacteria like salmonella and E. coli can lurk in raw flour from the soil that the wheat was harvested in and come to life when re-hydrated in dough — after all, bacteria only needs food, warmth and moisture to thrive.

So until that dough or brownie mix is baked in the oven, you should be aware of the risk of licking that finger, especially for children and people who are pregnant or immunocompromised. The CDC has investigated several outbreaks from flour and cake mix just in the last few years.  

What about cookie dough ice cream or other products with batter meant to be eaten without cooking? If you got it from the store, it’s likely been pasteurized or heat-treated, so no need to worry.  

Raw produce

Believe it or not, according to the CDC, the category of food responsible for the highest number of foodborne illness outbreaks might seem like the most innocuous of all: produce, especially leafy greens.

The soil that lettuce, spinach, cucumbers and carrots are grown in contains microbes — not to mention that hands of the people harvesting, transporting and processing it — and because people often eat this kind of produce raw, bacteria that might be lingering on it can infect you.

Of course, the answer is not to stop eating leafy greens or other raw vegetables, given how good they are for you, unless you’re immunocompromised and especially vulnerable. Instead, the best thing you can do is wash your produce to get rid of any soil particles that might contain pathogens. That includes produce with skin, especially if it's rough, like avocado and cantaloupe, which could be hiding germs that make it into the flesh when you cut into it.  

If you want to be extra careful, you could stick to heads of lettuce and greens that come from a single farm, and avoid boxed or bagged salads whose contents come from multiple sources. That’s because the more places the produce comes from, the higher the chances one of those places had a pathogen present, which could cross-contaminate the rest.  

At the end of the day, it’s up to you how careful you want to be. But, before making a decision about whether to pop a piece of sashimi or spoonful of batter in your mouth, it is important to know the risks — and how to lessen them.