The CDC specifically identifies raw aquatic plants, including watercress, as foods that can transmit certain parasites in places where contamination occurs.
The risk depends heavily on where the food was grown, the quality of the water, and how the food was handled.
If you are unsure about the safety of a raw aquatic plant, cooking it properly is generally a safer option than consuming it raw.
5. Shellfish
Shellfish such as oysters, mussels, clams, and other mollusks can filter large amounts of water as they feed.
If the surrounding water is contaminated, microorganisms can accumulate in the shellfish.
Raw or undercooked shellfish can therefore carry foodborne hazards, including certain parasites and bacteria.
Cooking shellfish thoroughly helps reduce the risk. The CDC recommends cooking shellfish until the shells open during cooking or the flesh becomes pearly or white and opaque.
Why Proper Preparation Matters
The presence of a food on this list doesn’t mean the food is inherently dangerous.
The real issue is often how the food is grown, handled, stored, and prepared.
For example, properly cooked meat is much safer than raw or undercooked meat. Washed produce is safer than unwashed produce, and properly cooked seafood is safer than raw seafood.
Food safety also depends on preventing cross-contamination.
If raw meat or seafood touches a cutting board, knife, countertop, or other food, microorganisms can spread to foods that are eaten without cooking.
Simple Ways to Reduce Your Risk
You don’t need complicated routines to improve food safety.
Cook Food Thoroughly
Use a food thermometer when appropriate.
The CDC recommends poultry be cooked to 165°F (74°C), ground meat to 160°F (71°C), and whole cuts of beef, pork, veal, and lamb to 145°F (63°C), followed by a three-minute rest.
Wash Fresh Produce
Rinse fruits and vegetables under running water before eating or cutting them.
Pay particular attention to produce that will be eaten raw.
Keep Raw Foods Separate
Use separate cutting boards or thoroughly wash and sanitize surfaces after preparing raw meat or seafood.
Don’t allow raw meat juices to come into contact with ready-to-eat foods.
Choose Safe Seafood
If you are concerned about parasites, choose properly cooked fish and shellfish instead of eating them raw or undercooked.
Store Food Properly
Keep foods refrigerated when necessary and avoid leaving perishable foods at unsafe temperatures for extended periods.
Who Needs to Be Especially Careful?
Although anyone can develop foodborne illness, certain groups have a higher risk of severe complications.
These include young children, adults over 65, pregnant people, and individuals with weakened immune systems.
For these groups, avoiding raw or undercooked animal products and following careful food-preparation practices is especially important.
The Bottom Line
Parasites aren’t something you need to fear every time you eat meat, fish, vegetables, or shellfish.
The important point is understanding that some foods can carry parasites when they are raw, undercooked, unwashed, or contaminated during handling.
Cooking food properly, washing fresh produce, preventing cross-contamination, and practicing good kitchen hygiene can dramatically reduce foodborne risks.
So you don’t need to eliminate these foods from your diet.
You simply need to prepare them safely.
