Is Sushi Safe To Eat? Health Risks of Eating Sushi
Updated: Oct 27
Mercury, parasites, bacteria and foodborne illness are just some of the associated health risks of eating sushi.
Sushi is perceived as a high protein, healthy meal that is better than fast food options for lunch or dinner and has become quite popular. Unfortunately, most sushi is made with fish that contain high levels of mercury. Tuna, yellowtail, bluefin, sea bass and lobster are popular in sushi rolls and sashimi but have such high amounts of mercury that they can cause serious problems. Symptoms of mercury toxicity include memory problems, muscle weakness, numbness and tingling, tremors and irritability.
Sushi sounds like a quick and easy meal, but there are significant health risks associated with eating sushi. For one, all fish contain some level of mercury, but most of the fish that is used in sushi rolls and sashimi are large fish, such as tuna, yellowtail, bluefin, sea bass and lobster, and they have the highest amounts of mercury. Symptoms of mercury toxicity include memory problems, muscle weakness, numbness and tingling, tremors and irritability. If you don't want to give up sushi, then at least choose lower mercury fish, such as salmon and shrimp.
Eating raw sushi also puts you at risk for infections. There are a number of different types of parasites found in raw fish that can cause serious illness. For example, tapeworm, which was previously only found in fish from Asia such as trout, pike and sea bass, has now been found in Alaskan salmon. The parasite that is on the rise is Anasakiasis, or herring worm disease. It is caused by the parasite, Anisakis simplex, which is a type of roundworm. Anisakis attaches itself to the stomach or intestines and causes acute abdominal pain, vomiting and fever. In some cases, it can lead to an allergic, anaphylactic reaction.
There are other types of infections also commonly found in sushi. Listeria is a dangerous bacterium that can be found in smoked and raw fish, amongst other foods such as deli meat and soft cheeses and can cause serious complications and even miscarriage in pregnant women. Salmonella poisoning can also occur from sushi. Even viral infections like norovirus have been linked to eating raw sushi.
Toxin exposure from sushi is significant. PCB's and pesticides have been found to contaminate farm raised fish as well as wild fish from the pacific. Ciguatoxins are toxins produced by marine algae microorganisms that affect fish that feed near reefs, such as red snapper, grouper, jack and barracuda. The toxin, like mercury, is found in larger fish and is not destroyed with cooking. It can produce gastrointestinal, cardiac and neurologic symptoms and has been associated with a condition known as Chronic Inflammatory Response Syndrome (CIRS). Scombroid food poisoning is another food-borne illness but it is not caused by a specific organism but rather by histamine that forms when fish are not kept cold enough and start to decay. Certain fish are more likely to be implicated in Scombroid syndrome: tuna, mackerel, mahi-mahi and bluefish. The excess histamine does not get destroyed during heating and can cause allergic reactions and even anaphylaxis.
If you don't want to give up sushi, then at least choose lower mercury fish, such as salmon and shrimp.
WHY SUSHI ISN’T A HEALTH FOOD
Sushi is most definitely not a health food, at least not given our current food supply. Hundreds or thousands of years ago, when our waters were clean and unpolluted, sushi would have been a health food. Fish is rich in omega-3 fatty acids which is good for your heart and the brain but given the number of potential risks from eating fish, it is probably best to buy a high-quality fish oil supplement that has been rigorously tested to ensure that it is free of mercury and other toxins.
HOW TO MITIGATE SUSHI HEALTH RISKS
The best way by far to mitigate health risks is to not eat sushi. If you are not willing to give it up, there are a few things to keep in mind:
1. CHOOSE A REPUTABLE RESTAURANT: From a parasite and infection perspective, choose a reputable restaurant and find out how they process the fish before turning it into sushi. The fish should be flash frozen solid and stored in a commercial freezer for at least 15 hours to kill whatever parasites might be there.
2. CHOOSE SMALL FISH: To avoid mercury and other toxins, choose smaller fish, which will naturally contain a lower amount of toxins.
3. RESEARCH THE SUPPLIERS: Ensure that restaurants are not buying fish from suppliers who harvest the fish near reefs to avoid Ciguatoxins and avoid eating fish that might not have been kept cold properly to avoid Scombroid.
4. EAT SUSHI QUICKLY: Eat your sushi immediately and do not leave it out at room temperature.
SUSHI TO AVOID AND SUSHI THAT IS SAFE
There really isn't a "best" fish when it comes to sushi because each fish has its own set of issues. To avoid mercury, choose smaller fish and salmon. To avoid parasites, tuna might be best because it rarely acquires parasites due to its life cycle. But tuna is high in mercury so it would not be a good choice for other reasons. Salmon is typically the go-to fish because it is lower in mercury, but some salmon is very high in PCB’s, pesticides and roundup. Even wild salmon might have similar issues depending on where it comes from. Two of my favorite fish that have the lowest amounts of toxins and are great sources of omega-3 fatty acids and protein are not eaten as sushi. They are anchovies and sardines.
Click here to read my full interview with INSIDER on Sushi. "6 horrifying things that can happen to your body when you eat sushi."