Health Benefits of Eating Fish

Nutrition Studies Explore Health Benefits of Eating Fish

Ongoing studies by U.S. agricultural scientists are helping to uncover new details about how omega-3 fatty acids, common in fish like salmon, may help protect people from chronic diseases such as diabetes.

Salmon and albacore tuna, for example are rich in healthful natural compounds known as omega-3 fatty acids.

Ongoing studies by U.S. Department of Agriculture (USDA) scientists are helping uncover new details about how these fish-oil components help protect us from chronic diseases.

In an early study, the researchers investigated the interplay of two omega-3 fatty acids from fish oil-DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) and a third fatty acid, CLA (as trans-10, cis-12 CLA) available as dietary supplements.

The 8-week test indicated that DHA protected against two harmful side effects of CLA: CLA-induced insulin resistance and CLA-induced non-alcoholic fatty-liver disease. In contrast, EPA offered only partial protection against CLA-induced non-alcoholic fatty liver disease and provided no protection against insulin resistance. If untreated, insulin resistance can lead to diabetes. An estimated 36 million to 57 million Americans are insulin-resistant. Non-alcoholic fatty liver disease can result in cirrhosis of the liver or liver cancer. The study appeared in a 2007 issue of Metabolic Syndrome and Related Disorders.

In related work, published in a 2009 article in Current Opinion in Clinical Nutrition and Metabolic Care, researchers reviewed results from several dozen EPA and DHA studies. In their review, the scientists indicate that findings reported in the past decade have been inconsistent in regard to the effects of EPA and DHA on insulin resistance in human volunteers.

Their review underscores the need for new investigations, with larger numbers of volunteers. Nutrition scientists will conducts further studies to determine if dietary intake of DHA has the potential improve the ability of adult, pre-diabetic volunteers to use insulin efficiently, and thus help delay onset of diabetes. Such research might reveal more about the specific mechanisms of action that DHA and EPA use, the sites upon which they act in the human body, and the genes that control these mechanisms.

Source: October 2010 issue of Agricultural Research magazine, available online at: http://www.ars.usda.gov/is/AR/archive/oct10/nutrition1010.htm.