1) What are omega-3 fatty acids and why are they called “essential fatty acids?”

Omega-3 fatty acids are a form of polyunsaturated fats, one of three basic types of fat that the body derives from food. (Saturated fat and monounsaturated fat are the others.) All polyunsaturated fats, including the omega-3s, are increasingly recognized as important to human health. However, the body cannot produce them on its own. For this reason, omega-3s must be obtained from food sources like fish, thus making these fats "essential."

Two high-quality types of omega-3s, DHA and EPA, can only be found in fish.  So it’s critical to include at least two fish meals per week in a balanced diet to get the best quality omega-3s while enjoying a delicious, low calorie, high protein food.

2) I’ve heard omega-3s in fish are good for the heart.  Why is this true?

Fish is a good source of protein and most varieties are free of or very low in saturated fats, which can contribute to high blood cholesterol levels.  Many types of seafood contain “good” kinds of fats, which are unsaturated fats, like omega-3 fatty acids. 

Doctors at Harvard Medical School have found evidence to suggest that the omega-3 fats in certain types of fish can stop dangerous irregular heart rhythms, which can trigger heart attacks or sudden death. This study is one of the latest to highlight the potential health benefits of eating fish. Numerous other studies have shown that omega-3 fatty acids can protect against heart disease and stroke.  For these reasons, the American Heart Association recommends eating fish at least two times per week. http://www.americanheart.org/presenter.jhtml?identifier=3013797

3) Why do the benefits of eating fish at least twice a week outweigh the risks of exposure to mercury or other contaminants? 

Published in the November 2005 issue of the American Journal of Preventive Medicine, a study from the Harvard Center for Risk Analysis shows that the benefits of consuming fish far outweigh the risk calculable from minimal exposure to mercury. 

The study’s risk and benefit analysis found that consumers who eliminate fish from their diet risk a higher incidence of stroke and heart disease.  In addition, the babies of expectant moms who stop consuming fish lose the benefits omega-3s have on brain and nervous system development. Instead, researchers suggested consumers should follow government advice to eat fish weekly, choosing from a variety of fish low in mercury so they can enjoy the health benefits associated with omega-3 fatty acids without concern about mercury exposure. 

4) Isn’t fish high in cholesterol?

Consumers are concerned about the cholesterol content of some foods (or dietary cholesterol), but in the case of shrimp and other seafood the cholesterol story is different. Shellfish are very low in saturated fat which is the major contributor to blood cholesterol, and the majority of other fish are low in dietary cholesterol.  Research has shown that the low total fat combined with the high percentage of good fats – like omega-3s – in seafood reduces the amount of blood cholesterol produced in the body after eating a meal of fish. 

5) What is mercury?

Mercury occurs naturally in the environment in volcanoes. Mercury in the air can fall into streams and be turned into methylmercury by living organisms in the water.  Fish can absorb small amounts of methylmercury as they feed in these waters.  Some types of fish and shellfish contain more methylmercury than others, depending on their diets and their age.

6) Who should be concerned about methylmercury exposure from fish?

Experts recommend that women who are pregnant, planning to become pregnant or nursing consume less of certain types of seafood than recommended for other adults.  If you are a woman of childbearing years and are concerned about how to keep fish in your diet during your pregnancy, consult the FDA/EPA Joint Advisory on Mercury and Fish at http://www.cfsan.fda.gov/~dms/admehg3.html.

7) As a pregnant woman, should I keep fish in my diet?

Absolutely!  According to the FDA/EPA Advisory, “Fish and shellfish are an important part of a healthy diet. Fish and shellfish contain high-quality protein and other essential nutrients, are low in saturated fat, and contain omega-3 fatty acids. A well-balanced diet that includes a variety of fish and shellfish can contribute to heart health and children's proper growth and development. So, women and young children in particular should include fish or shellfish in their diets due to the many nutritional benefits.”

Furthermore, researchers at the Harvard Center for Risk Analysis recently found that pregnant women, who are at more risk from mercury exposure, could increase the cognitive development benefits for their unborn child by eating the recommended servings of fish per week, while choosing from a variety of fish and seafood low in mercury. 

8) I’m NOT pregnant, nursing or thinking of becoming pregnant.  Do I need to worry about what fish I eat?

In short, NO.  According to the Centers for Disease Control and Prevention (CDC), not one single American has been adversely affected by mercury exposure from fish.  Fish is an important part of a healthy, balanced diet.  In fact, in its Dietary Guidelines and Food Pyramid, the U.S. government prominently features recommendations for Americans to eat at least two weekly servings of fish in their diets. Proteins, vitamins and fatty acids found in seafood contribute to improved cardiovascular and neurological health as well as healthy development in children.  Visit: www.MyPyramid.gov for more information.

9) Can methylmercury be removed from fish? 

No.  Mercury has always existed in small amounts in fish and other foods.  Some natural sources of mercury include volcanoes, cracks in the earth’s crust, forest fires, and others.  In fact, according to research conducted by Alaska public health officials, eight 550-year-old Alaskan mummies (four adults and four infants) that were tested contained levels of mercury twice as high as pregnant Alaskan women today.  The researchers concluded that the remains “provide evidence that humans have always been exposed to naturally occurring mercury through fish and marine mammals in their diets.” 

10) The FDA set a limit for mercury in fish, but what does it mean?

Mercury levels for most fish range from non-detectable to 0.5 parts per million (ppm).  In a few species, mercury levels can reach 1 ppm, the limit the U.S. Food and Drug Administration (FDA) suggests for fish intended for human consumption.  However, the average concentration in the 10 most popular commercial species is 0.12 ppm or about 8 times lower than the FDA limit.  http://www.aboutseafood.com/media/top_10.cfm

11) What if I catch my own fish instead of buying it at the store?

The U.S. Food and Drug Administration and Environmental Protection Agency advise Americans to check local advisories about the safety of fish caught by family and friends in your local lakes, rivers, and coastal areas.