HAD ENOUGH TURKEY? HOW ABOUT HAVING FISH FOR A CHANGE?
After all the turkey you probably ate on Thanksgiving plus all the turkey leftovers these past couple days, you may be ready for a change. Adding more fish into our weekly diet has big benefits, especially for us older adults who want to reduce the risk of heart disease and other senior-associated maladies.
I found the Harvard School of Public Health online article, Fish: Friend or Foe? that summarizes the major benefits and minor risks of eating fish. Here are excerpts:
Fears of contaminants make many unnecessarily shy away from fish
Fish is a very important part of a healthy diet. Fish and other seafood are the major sources of healthful long-chain omega-3 fats and are also rich in other nutrients such as vitamin D and selenium, high in protein, and low in saturated fat. There is strong evidence that eating fish is good for the heart and blood vessels. An analysis of 20 studies involving hundreds of thousands of participants indicates that eating approximately one to two 3-ounce servings of fatty fish a week—salmon, herring, mackerel, anchovies, or sardines—reduces the risk of dying from heart disease by 36 percent.
Eating fish fights heart disease in several ways. The omega-3 fats in fish protect the heart against the development of erratic and potentially deadly cardiac rhythm disturbances. They also lower blood pressure and heart rate, improve blood vessel function, and, at higher doses, lower triglycerides and may ease inflammation. The strong and consistent evidence for benefits is such that the Dietary Guidelines for Americans, the American Heart Association, and others suggest that everyone eat fish twice a week.
Unfortunately, fewer than one in five Americans heeds that advice. About one-third of Americans eat seafood once a week, while nearly half eat fish only occasionally or not at all. Although some people may simply not like fish, the generally low consumption is likely also caused by other factors, including perceptions about cost, access to stores that sell fish, and uncertainty about how to prepare or cook fish. Still others may avoid seafood because they worry that they will be harmed by mercury, pesticide residues, or other possible toxins that are in some types of fish.
Should you forgo fish because of the contaminants they might carry? It’s a controversial topic that is often fueled more by emotion than by fact. Here’s what’s known about the benefits and risks of eating fish and other seafood:
Benefits & Risks
- Known or likely benefits:In a comprehensive analysis of human studies, Harvard School of Public Health professors Dariush Mozaffarian and Eric Rimm calculated that eating about 2 grams per week of omega-3 fatty acids in fish, equal to about one or two servings of fatty fish a week, reduces the chances of dying from heart disease by more than one-third.
- Possible benefits:Eating fish once or twice a week may also reduce the risk of stroke, depression, Alzheimer’s disease, and other chronic conditions.
- Possible risks: Numerous pollutants make their way into the foods we eat, from fruits and vegetables to eggs and meat. Fish are no exception. The contaminants of most concern today are mercury, polychlorinated biphenyls (PCBs), dioxins, and pesticide residues. The effect of the far lower levels of mercury currently found in fish are controversial. They have been linked to subtle changes in nervous system development and a possible increased risk of cardiovascular disease. The case for PCBs and dioxins isn’t so clear. A comprehensive report on the benefits and risks of eating fish compiled by the Institute of Medicine calls the risk of cancer from PCBs “overrated.”
Striking a Balance
Avoiding fish is certainly one way to avoid mercury or PCBs. But is that the wisest choice, given the benefits of eating fish? Drs. Mozaffarian and Rimm put this in perspective in their analysis in the Journal of the American Medical Association. First, reviewing data from the Environmental Protection Agency and elsewhere, they calculated that if 100,000 people ate farmed salmon twice a week for 70 years, the extra PCB intake could potentially cause 24 extra deaths from cancer—but would prevent at least 7,000 deaths from heart disease. Second, levels of PCBs and dioxins in fish are very low, similar to levels in meats, dairy products, and eggs. Third, more than 90 percent of the PCBs and dioxins in the U.S. food supply come from such non-seafood sources, including meats, dairy, eggs, and vegetables. So, given these limited health effects, low levels in fish, and major sources from other foods, the levels of PCBs and dioxins in fish should not influence your decision about which fish to eat (just as it does not influence your decision about whether or not to eat vegetables, meats, dairy products, or eggs, the major sources of PCBs and dioxins). One exception: if you eat local freshwater fish caught by friends or family, it makes sense to consult local advisories about the amounts of such fish you should eat.
At the levels commonly consumed from fish, there is also limited and conflicting evidence for effects of mercury in adults; thus, the Environmental Protection Agency, the Food and Drug Administration, the Institutes of Medicine report, and the analysis by Mozaffarian and Rimm all conclude that this evidence is insufficient to recommend limitations on fish intake in adults, given the established benefits of fish consumption for cardiovascular disease. In fact, the easiest way to avoid concern about contaminants is simply to eat a variety of fish and other seafood.
Recommendations
- Don’t eat shark, swordfish, king mackerel, or tilefish (sometimes called golden bass or golden snapper) because they contain high levels of mercury.
Eat up to 12 ounces (two average meals) a week of a variety of fish and shellfish that are lower in mercury. Shrimp, canned light tuna, salmon, pollock, and catfish are low-mercury fish. Albacore (“white”) tuna has more mercury than canned light tuna. So limit your intake of albacore tuna to once a week.- Check local advisories about the safety of fish caught by family and friends in your local lakes, rivers, and coastal areas. If no advice is available, eat up to 6 ounces (one average meal) per week of fish you catch from local waters, but don’t consume any other fish during that week.