Raw fish may harbor parasites as well as bacteria and viruses. The Food and Drug Administration (FDA) requires that most fish used commercially for sushi be frozen to kill parasites. Well-trained sushi chefs know how to buy, examine, store and handle fish to minimize risks. While chefs are licensed in Japan, they are not in the U.S. Avoid sushi if you are in frail health, have a compromised immune system or are pregnant or a young child. Everyone should avoid raw freshwater fish (such as pike, yellow perch and brook trout).
Sushi can be a good source of healthful omega-3 fats, protein and a range of nutrients. And it’s generally low in calories, with about 40 to 60 calories per piece of sashimi and about 300 to 400 calories, on average, per large eight-piece roll. But many Japanese restaurants in the U.S. serve big portions and large combination plates. Watch out, also, for nontraditional ingredients like cream cheese, fried onion, smoked duck, even seared foie gras, which add calories and unhealthful fats.
Many sushi ingredients and condiments—such as seaweed, soy sauce and pickled ginger—are high in sodium. Sashimi typically has little sodium (less than 50 milligrams per piece), but many rolls have between 400 and 800 milligrams; a few may top 1,000 milligrams. A tablespoon of soy sauce has about 900 milligrams; the packets often provided have about 500 milligrams each. Ask for reduced-sodium soy sauce, if available, and use only a little.
We don’t recommend it, unless you use cooked fish or just vegetables. Home-prepared raw fish is a common source of parasitic infection in this country. Fish at the market may not be sushi-grade. And if you freeze the fish to kill parasites, your home freezer probably doesn’t get cold enough to do the job.
Buy take-out sushi only from reputable, clean establishments. Make sure it is fresh and refrigerated below 41°F—though that may be hard to tell. If the containers are stacked, choose one from the bottom, where it is cooler. Like raw fish, cooked rice is susceptible to bacterial growth if it is not properly refrigerated.