Have you ever eaten a plate of sushi, a ceviche, or marinated anchovies and hours later started to feel stomachache, nausea, or vomiting? It may seem like a simple upset, but in some cases those symptoms hide anisakis.
Isabel Belaustegui, a physician specializing in integrative medicine and a contributor to ZZEN Labs, explains how to prevent it and debunks one of the great summer myths: neither lemon nor vinegar are enough to eliminate this parasite.
“Vinegar Does Not Freeze”: the mistake that can turn a summer dish into a problem
Anisakis is present in certain fish and marine cephalopods and can cause anisakiasis when live larvae are ingested. The problem is that its early symptoms can be easily mistaken for a routine upset.
Abdominal pain, nausea, and vomiting that appear a few hours after eating raw or undercooked fish are some of the signs to watch for. Additionally, the parasite can also trigger allergic reactions that, in some cases, can be serious.
And here appears one of the most widespread errors: thinking that preparing the fish with lemon, vinegar, or a marinade is enough.
That is not the case.
Marinated anchovies, ceviche, sushi, and tartares require proper precautions when prepared with fish that might contain anisakis. The acid from lemon or vinegar should not be confused with an effective method of freezing or cooking.
For Belaustegui, the key is to replace fear with knowledge. “It’s not about obsessing, but about learning to recognize the processes and returning real foods to the foreground,” she notes.
The five-day trick many people don’t know
If you plan to prepare raw or lightly cooked fish at home, freezing is one of the main prevention measures.
In a domestic freezer that reaches −15 °C or lower, AESAN recommends freezing the fish for at least five days. If you’re not sure the freezer reaches that temperature, a simple alternative is to buy fish that has already been frozen.
The other major barrier is cooking. The interior of the piece must reach at least 60 °C for one minute. It’s not enough for the exterior to be browned: the heat must penetrate to the inside.
A piece about 2.5 centimeters thick may require around ten minutes of total cooking time, turning it halfway, although the actual time will depend on size and the method used.
The rule is simple: if the fish is going to be eaten raw or lightly cooked, prevention must come first.
These are the symptoms you should not ignore after eating fish
Anisakis does not always manifest in the same way. Some people may experience digestive discomfort, while others develop an allergic reaction.
Therefore, after consuming raw or undercooked fish, it’s worth paying attention if the following occur:
- Severe abdominal pain.
- Persistent nausea or vomiting.
- Urticaria or itching.
- Swelling of lips or face.
- Difficulty breathing.
- Blood in the stool or other concerning symptoms.
In the case of intense symptoms or those that don’t fit a fleeting upset, it’s advisable to consult a healthcare professional. If breathing difficulties or a severe allergic reaction occur, seek urgent medical attention.
The doctor also focuses on what happens before sitting down at the table
Beyond anisakis, Belaustegui advocates a global view of digestive health. “The health of the body is forged in the stomach. When balance is disrupted, we notice it throughout the entire organism,” she says.
Her approach involves paying attention to daily habits and giving greater prominence to real foods, rest, and stress management, without turning eating into a constant source of worry.
Because enjoying the summer does not mean giving up sushi, ceviche, or a good plate of anchovies. It means knowing what risks exist, how to prevent them, and when an alleged “indigestion” deserves more attention.
