Not All Fish Are Created Equal!

By Thomas B. Gilliam, Ph.D.

After reading the Move It. Lose It. Live Healthy. book, you have decided to eat more fish to reduce your risk of coronary heart disease. So you go to your local grocery store and purchase several farm-raised fillets of tilapia, catfish, and Atlantic salmon. You go home and are ready to get started on your new dietary selection: fish. Well, not all fish are created equal in terms of being beneficial to your health.

In a recent study that appeared in the July 2008 Journal of the American Dietetic Association by K. Weaver and colleagues entitled “The Content of Favorable and Unfavorable Polyunsaturated Fatty Acids Found in Commonly Eaten Fish,” the results might surprise you.

The health benefit from fish is derived from the concentration of Omega-3 fatty acid.  Omega-3 has been shown to reduce your risk for coronary heart disease. As a result, Americans have been buying large quantities of fish. With increase demand for fish, many fish farms across North America have evolved. It is not uncommon when purchasing fish that the fish has been farm-raised—not caught in the wild. 

But here is the surprise. The four most common fish eaten in the United States today are farm-raised tilapia, catfish, Atlantic salmon, and trout. Even though the fish is farm-raised, the Atlantic salmon and trout have favorable amounts of Omega-3—amounts that can be beneficial. However, the farm-raised tilapia and catfish do not. In fact, they have higher levels of saturated fats and higher levels of another Omega fatty acid that are detrimental to your health.

You might be asking which fish have the highest concentrations of Omega-3. The article categorized fish into three categories: 1. those with at least 500 mg of Omega-3 per 100 grams of weight, 2. those between 150 and 500 mg of Omega-3, and 3. those with fewer than 150 mg of Omega-3 (shown in the following table). The fish are listed from top to bottom based on the most Omega-3 within each category.

Even though the farm-raised tilapia and catfish have a good amount of Omega-3 per 100 mg of fish (second column), the higher levels of saturated fats and another Omega fatty acid negate their benefit. The higher levels of saturated fats and another Omega fatty acid were not found in any significant amount in the other fish—even the farm-raised fish. If you are interested in digesting the greatest concentrations of Omega-3, you should choose from the list of fish found in column one. The fish listed in columns two and three still have Omega-3s, but just not as much.