From salmon to tuna to trout, fish have been swimming onto the plates of health-conscious consumers in recent years. It's easy to understand why. Fish tops the list of heart-healthy foods, according to Susan Roberts, Ph.D., a professor of nutrition at Tufts University in Boston. While some nuts and green vegetables have heart-protecting properties, Roberts said they can't compare to fish in the heart-health sweepstakes.
You can net the benefits of fish in many ways -- but there may be a catch. Not all fish have top-of-the-line properties for heart protection, and some may even contain contaminants that could potentially harm your health. Getting up to speed on the fish facts, myths and trends can help you keep your heart in tiptop shape. Let's go fishing for the real scoop on fish's heart-protecting properties.
Generally, cold-water fish have more heart-healthy fish oils than warm-water fish. Salmon, tuna, herring, mackerel, Atlantic halibut and sardines are the richest sources of omega-3 fatty acids.
Elisa Zied, R.D., author of "Nutrition at Your Fingertips"
How Fish Helps Your Heart
Unlike beef, fish is low in artery-clogging saturated fat. Plus, the potassium, magnesium and niacin in fish help lower blood pressure and increase good cholesterol levels, notes registered dietitian Elisa Zied, a former spokeswoman for the American Dietetic Association and author of "Nutrition at Your Fingertips."
The real treasure chest of wellness-boosting properties, however, is in the omega-3 fatty acids. These fish oils help the heart in a multitude of ways: They protect the arteries from damage by keeping platelets from sticking together, and they also increase good cholesterol levels, lower blood pressure and triglyceride levels, and prevent heart arrhythmias that can lead to sudden death. In a study of more than 3,000 people published in the May 2007 issue of "The American Journal of Clinical Nutrition," researchers found that those who consumed about two and a half servings of fish per week had a 29 percent lower risk of life-threatening abnormal heartbeats than people who ate less fish.
Because of the overwhelming evidence of fish's heart-protecting properties, the American Heart Association recommends eating fish twice a week.
Best Types of Fish
Not all fish are loaded with good-for-your-heart oils. Some lack sufficient omega-3s to protect your heart.
"Generally, cold-water fish have more heart-healthy fish oils than warm-water fish," Zied said. "Salmon, tuna, herring, mackerel, Atlantic halibut and sardines are the richest sources of omega-3 fatty acids." Catfish, pike, red snapper, trout and other warm-water dwellers aren't as friendly to your heart, because they have lower levels of omega-3s. Ocean fish also tend to be safer than lake fish, which are more likely to contain environmental pollutants.
Because children and unborn babies are especially vulnerable to mercury, the Food and Drug Administration advises children under age 12 and expectant mothers to avoid eating fish with the potential for high levels of mercury -- king mackerel, tilefish, shark and swordfish -- and to eat no more than 12 oz. per week of fish that are lower in mercury, such as salmon and canned light tuna.
It's a myth that all shellfish are bad for your heart. "For years, it was thought that shellfish like lobster and king crab had high levels of cholesterol that could endanger the heart, but we now know they contain no more cholesterol than chicken or lean meat," said Patricia Bannan, R.D., a nutritionist in Los Angeles and author of "Eat Right When Time Is Tight."
Shrimp, however, is higher in this artery-clogging fat. "One serving of shrimp has about three times the amount in a serving of lean beef," Bannan said. If you already have high cholesterol, you may want to steer clear of shrimp and have lower-cholesterol crab, lobster, clams or oysters instead. Crabs, lobster and clams are also rich in zinc, a trace nutrient needed for overall good health.
Wild Fish vs. Farmed
As demand for heart-healthy fish has increased, waters in some parts of the world have been overfished. The solution has been to grow fish in farms.
According to the World Health Organization, one-third of the world's fish supply comes from fish-farm operations. This trend has brought down the price of fish, but it may not be a good thing when it comes to your health.
Farmed fish are raised in water-filled pens, where they are less active and eat mass-produced food. Wild fish, on the other hand, are much more active as they seek out prey, and that prey is more nutritious than the food that farmed fish eat. "Wild fish tend to be leaner and have higher amounts of omega-3 oils," Bannan said. They may also be safer. A 2003 report from the Environmental Working Group stated that farmed salmon contained five to 10 times the amounts of the toxic environmental chemical PCB as wild salmon.
So if all you can find is farm-raised fish, which must be labeled as such in grocery stores, should you avoid eating fish altogether? Most experts say no. "The benefits of eating fish outweigh any potential risks," Zied said. To reduce potential exposure to contaminants, however, the American Heart Association suggests removing the skin and surface fat before cooking.
Supplements and Fortified Foods
Some people shy away from eating fish because it tastes so, well, fishy. Fortunately, you can get the heart-health benefits of omega-3s without eating fish.
"Many types of foods now have omega-3s added to them," said Bannan, including milk, eggs, yogurt, cheese, cereal, tortillas and granola bars. Fortified foods taste the same as foods without the heart-helping additions.
One downside: They're usually pricier. Are they worth the extra cost? They might be if you never eat fish, but Zied prefers the real thing. "Fortified foods contain a less-potent form of omega-3s than fish," Zied explained. "Plus, fish contain other heart-healthy nutrients not contained in fortified foods."
Taking a daily fish oil supplement is another option if you're not a big fish fan. But if you take medications, Zied cautions that you should talk to your doctor first, because fish oil capsules can interact with some medicines and cause side effects.
The bottom line: If you want to do your heart good, go fish. Whether you add fish to your diet or take fish oil supplements, the omega-3s will help keep your heart healthy now and down the road.