When thinking about what to have for dinner, fish is a good choice. Fish is promoted as a heart-healthy choice for several reasons. First, fish is low in saturated fat and can benefit the cardiovascular system when replacing other meat that is higher in saturated fat. Also, omega-3 fatty acids in fish are considered to be a "good" fat that benefit heart health and is essential in pregnancy and infant development.
In fact, the American Heart Association recommends two fish meals a week for heart disease prevention. Those already diagnosed with heart disease are advised to consume three fish meals per week. Knowing a few additional facts about eating fish can be beneficial to your health.
Farmed vs. wild-caught salmon.
PCBs, or polychlorinated biphenyls, are banned industrial pollutants that linger in our environment. PCBs can accumulate in the body and have been shown to cause cancer in lab animals. Studies have found high levels of PCBs in farmed salmon since their feed may contain PCB. It’s unnecessary to avoid farmed salmon, but it’s advisable to include it only occasionally in your diet and to choose farmed salmon from Chile when available. Keep in mind that eating farmed salmon instead of not eating salmon at all benefits your heart more than it increases your risk of cancer.
Wild-caught salmon is preferable because these fish have a more varied diet. A new law requires that supermarket fish be labeled by its country of origin and whether it is farmed or wild-caught. Most canned salmon is wild-caught. Salmon, a naturally fatty fish, is rich in omega-3 fatty acids which promotes heart health.
Mercury-a health concern.
Mercury is a metal that occurs naturally in our environment, but additional levels in fish may come from industrial pollution that has settled into the oceans, lakes and rivers where bacteria change it into toxic methyl mercury. Mercury concentrations can be a concern when big fish eat little fish that feed on plankton in polluted water. As a result bigger fish likely have accumulated more mercury.
Mercury can damage developing nervous systems when it is consumed by children or pregnant and breastfeeding women. The current recommendation is that pregnant and breast-feeding women and children up to age 12 can safely consume 12 ounces per week of cooked seafood and up to 6 ounces of white albacore tuna per week. Canned light tuna is lower in mercury than canned albacore tuna. Large predatory fish such as shark, swordfish, tilefish or king mackerel should be avoided because the concentration of mercury is likely to be much higher.
If you wish to monitor your own mercury consumption in fish, use the mercury calculator provided by the nonprofit group Take Action at www.gotmercury.org.
Certified organic seafood.
You won’t see the USDA’s certified organic logo on fish because there is not a USDA certification for organic seafood. A producer can call its’ seafood organic on the package but the claim is meaningless. Because the USDA does not oversee this label, there is no guarantee farm-raised salmon, for example, was raised on organic feed or that it is free of PCBs.
Other countries certify farmed seafood but standards are not uniform from country to country. Some fish farms are more ecologically sound than others. The Marine Stewardship Council (www.msc.org) is an example of a third-party certifier that monitors fishery management practices and ensures that certain fisheries are sustainably managed. This independent group monitors fisheries around the globe.
Cholesterol in shellfish.
Are you among those who think you can’t enjoy shrimp because you’re supposed to be limiting cholesterol in your diet to less than 200 milligrams? If so, please read on to learn the true fish facts. Even if your cholesterol is high, you can include shrimp in your diet. A myth that people with high cholesterol should avoid shrimp got started because it’s true that shrimp is high in dietary cholesterol, but that typically is not enough reason to avoid the food. Here is something to keep in mind: shrimp does have 165 mg of dietary cholesterol in a 3 ounce, cooked serving. That’s more than you’ll find in other shellfish — the same serving size of oysters, scallops, lobster, crab and clams ranges from 45 to 90 milligrams. However, the good news is that the saturated fat content of shellfish is low and saturated fat raises blood cholesterol much more than dietary cholesterol.
Last words about eating fish.
Eating fish at least twice a week will improve your heart’s health and reduce the likelihood of dying suddenly. Pay attention to recommended choices and amounts of fish, especially for children and pregnant and breastfeeding women, to control the amount of mercury consumed. It’s advisable to consume a variety of fish to avoid an excess of PCBs while still benefiting from the omega-3s.
Finally, some methods of preparation are better than others. Broil, bake or grill the fish on a rack instead of sauting or frying to allow the fat where the toxic chemicals concentrate to drain away while leaving beneficial omega-3s in your meal. Enjoy eating it to your heart’s content.
by Shirley Perryman, M.S., R.D.
Department of Food Science and Human Nutrition
Colorado State University
Cooperative Extension Specialist