An Overview of the Benefits and Risks of Fish Sushi

An Overview of the Benefits and Risks of Fish Sushi
by Edmond Ryan

Sushi has become a popular food choice in the US. Sushi is composed of rice steamed with sweet rice vinegar and may include vegetables and cooked or raw seafood. There is a recent trend for modern chefs to experiment with different ingredients, sauces, etc., but for this article, I will focus on the more traditional forms of sushi – specifically fish sushi. Eating a low-fat diet, high in Omega-3 fatty acids, and low in cholesterol is healthy, but the seafood that is served in sushi poses some risk of exposure to mercury and other toxins. Furthermore, our appetite for sushi poses a threat to certain species of fish due to overfishing. In this article I will provide an overview of some of the benefits and some of the risks involved in eating fish sushi. By making good choices, overall, the benefits of eating fish outweigh the risks


Benefits of Eating Sushi

Sushi is low in saturated fat, low in calories, and low in cholesterol. In addition, the vegetables and seaweed provide essential nutrients and micronutrients. Nori is the seaweed which is found in many types of sushi. Nori, or red algae, is a good source of calcium and other minerals, as well as vitamins, specifically vitamin B12 (

One of the benefits of fish sushi is its Omega-3 fatty acid content. Omega-3s are essential fatty acids that cannot be made by our bodies and which are important for growth and development and which also help in the prevention and treatment of heart disease. Other benefits that Omega-3 provides include helping to prevent mental illness ( and delaying some of the disabilities associated with aging ( Omega-3 also helps lower triglycerides in the blood ( A recent study of fish oils at the Columbia Institute of Human Nutrition has found that Omega-3 also helps prevent the buildup of fat in the aorta. (

Potential Risks of Sushi
Sushi does have some risks which can be minimized by making wise choices. There are many choices of what to order when at a sushi restaurant, but consumers should be aware of the consequences of their selections. The first of two risks I will discuss in this article is the risk associated with mercury contamination. The second, is the risk to the sustainability of the species that are harvested for our meals.

Mercury Contamination
Methylmercury accumulates in aquatic species, with higher concentrations found in the larger and older species such as tuna, shark, and tilefish. Industrial pollution releases mercury into the environment which eventually finds its way into streams and rivers and to the ocean.
Because of risks that mercury poses to an unborn child, woman who are pregnant should avoid eating fish with high mercury content. Women who plan on becoming pregnant should also avoid fish with hight levels of mercury because of the amount of time it takes the body to rid mercury from the bloodstream. The FDA and EPA have developed recommendations for reducing exposure to mercury in seafood:
  1. “Do not eat Shark, Swordfish, King Mackerel, or Tilefish because they contain high levels of mercury
  2. Eat up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury.
    1. Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish.
    2. Another commonly eaten fish, albacore ("white") tuna has more mercury than canned light tuna. So, when choosing your two meals of fish and shellfish, you may eat up to 6 ounces (one average meal) of albacore tuna per week.
  3. Check local advisories about the safety of fish caught by family and friends in your local lakes, rivers, and coastal areas. If no advice is available, eat up to 6 ounces (one average meal) per week of fish you catch from local waters, but don't consume any other fish during that week.”

Environmental Concerns
Our appetite for sushi causes concerns for the environment. Overfishing has led to dramatic decreases in the population of certain species. Bluefin tuna, which is called Hon Maguro and Toro (belly) on sushi menus, have been severely overfished. Demand is so great, that earlier this year, a 282 pound bluefin tuna sold for over $100,000 – a price equal to about $370 per pound. (

To help in making choices that are both sustainable and healthy, there are a number of guides available to help you make your decision. The Environmental Defense Fund, in collaboration with the Monterey Bay Aquarium and the Blue Ocean Institute has produced a Pocket Sushi Selector which can be printed or downloaded to a mobile phone. Each of the three organizations has a guide which helps in making ocean-conscious selections by seeing the impact to the population, its mercury content, and Omega-3 content (see links below for more about this).

Additional Resources
Environmental Protection Agency's Fish Advisories - Natural Resources Defense Council's Mercury Calculator: FDA's Center for Food Safety EDF Pocket Sushi Guide: Blue Ocean Institutes's Seafood Guide: Monterey Bay Aquarium's Seafood Watch: “The Cost of Luxurious Sushi” San Diego Reader

More pages