Chances are that you’ve thought about how best to get enough omega-3 fats into your diet. You’re well aware of the reported health benefits and have educated yourself on the richest sources (think SMASHT - we’ll spell out this acronym below). But since you’ve started paying more attention, you’ve heard that farm-raised salmon contains higher levels of environmental toxins, and you likely know that over-fishing has depleted a great percentage of the worldwide fishing stocks. The next time you sit down to dinner, how confident will you be in your ability to choose wisely, getting the healthiest fish possible while supporting sustainable fishing practices?
As a protein source, fish rates high. It is low in saturated fat, contains a healthy dose of vitamin D, and depending on the fish, is the richest dietary source of long-chain omega-3 fats. Researchers encourage us to consume omega-3 rich fish twice each week as a way to reduce our heart disease risk by 33%. Memorize the SMASHT acronym to learn the primary omega-3 fish. It stands for:
S Salmon M Mackerel A Anchovies S Sardines H Herring (actually classified as a sardine) T Tuna
Health Risks from Eating Fish Fish accumulate environmental toxins, including mercury and PCBs, from eating other marine life. As a general rule, the larger the fish, the greater the accumulation. How much these toxins affect individuals is unclear. Pregnant women, nursing women, and children are clearly more susceptible to the damaging effects of mercury.
Mercury Mercury is produced naturally (weathering of rocks and volcanic eruptions) and from industry, primarily from coal burning plants. It is estimated that the man-made production of mercury is three times greater than natural emissions. Whatever its source, as mercury settles in the environment, bacteria changes it into methylmercury, a toxic form particularly harmful to fetuses and developing children. Large, long-lived fish, like shark, swordfish, tilefish, and king mackerel, accumulate the highest levels of methylmercury. The FDA has established the following recommendations for pregnant women and children:
1. Do not eat shark, swordfish, king mackerel, or tilefish (golden bass, golden snapper).
Eat up to 12 ounces (2 average meals) a week of shrimp, canned light tuna, salmon, pollock, and catfish.
Eat up to 6 ounces (1 average meal) a week of albacore ("white") tuna.
2. 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.
3. Follow these same recommendations when feeding fish and shellfish to your young child, but serve smaller portions.
While it is difficult to find any clear recommendations from the EPA or FDA for fish intake for the healthy adult male and female (not child bearing), the best guideline is to limit high mercury fish (1.0 parts per million (ppm) methylmercury) to no more than 7 ounces per week, and medium mercury fish (0.5 ppm methylmercury) to 14 ounces or fewer each week. This fish are:
1.0 ppm: shark, swordfish, king mackerel, and tilefish (golden bass, golden snapper).
0.5 ppm: Largemouth bass, smallmouth bass, pickerel, walleye, marlin, orange roughy, grouper, red snapper, and tuna
Polychlorinated biphenyls (PCBs) PCBs are mixtures of over 200 individual chlorinated compounds that persist in the environment. All of these compounds are man-made; they have been used primarily as coolants and lubricants in electrical equipment since 1927 until they were gradually banned across the world starting in the late 1970s. The EPA estimates, however, that 150 million pounds of PCBs are still being dispersed throughout the air and water and nearly 300 million pounds remain in landfills. For more information: http://www.epa.gov/history/topics/pcbs/01.htm
Fish accumulate PCBs from feeding on other sea life. When consumed, PCBs cause birth defects and cancer in laboratory animals and are a suspected cause of cancer in humans. PCBs have been shown to impair immune function in humans. In one study, high consumers of fatty fish had significantly lower levels of natural killer cells (higher levels are more desirable) than those rarely consuming fatty fish.
Downsides of Fish Farming A study conducted by the Environmental Working Group (EWG) found that farmed salmon have 16 times the PCBs of wild salmon (4 times more than the levels found in beef and 3.4 times the levels in other seafood) because of PCB-laden fish meal used for feed. In its survey, seven of ten farmed salmon purchased in U.S. grocery stores were contaminated with PCBs at alarming levels. Based on the available evidence, EWG recommends that consumers choose wild instead of farmed salmon and limit farmed salmon intake to eight ounces per month. The industry is working to change the type of feed used, which has the potential to significantly reduce PCB levels.
Farmed fish are simply not as healthy as wild fish. One sign of this is in the differing levels of omega-3 fats. According to the EWG, a 2002 USDA analysis found that farmed salmon contain 35% fewer omega-3 fats than wild salmon. Yet, approximately 90% of the salmon eaten in the U.S. today comes from a farm. Unlike the shift that occurred with land animal production after WW II, fish farming did not become an industry norm until the 1980s. Like their land counterparts, fish farmers rely on antibiotics and other medications to control disease and use unnatural feed products to yield a bigger product in a shorter time period within a confined space. These changes have impacted both the health and quality of the fish and raise significant environmental issues such as the management of waste products, the cross breeding of escaped salmon with wild varieties, and the spread of parasites from fish pens to surrounding waters.
Sustainable Fishing Many global fish stocks are in jeopardy of being depleted. Despite warnings from scientists, Americans still regularly consume fish from fisheries that are in real danger aka red light fish. The National Audubon Society has developed a rating system red (avoid), yellow (be careful), green (enjoy) for the most popular fish based on the abundance of the fish, how they’re caught, and how well the fisheries are managed. An example of a popular fish that has been designated red (avoid) is the orange roughy. Scientists believe that it will be nearly impossible for the orange roughy to recover from over-fishing because it grows very slowly and does not breed until its 25-30 years old (some orange roughy fish live for 150 years). The fishery also has a very high by-catch* level, a factor that influences the rating system.
* By-catch: the number of creatures unintentionally snared in nets, including fish, birds, and turtles. For instance, for every pound of shrimp caught by trawl nets, over three pounds of by-catch are discarded.
Fish to Avoid (Red): Caviar (imported/wild caught), Cod (Atlantic), Chilean Sea Bass, Flounder and Soles (Atlantic), Grouper, Halibut (Atlantic), Monkfish, Orange Roughy, Red Snapper, Salmon (farmed, including Atlantic), Sharks, Shrimp (imported), Tuna (bluefin).
Pregnant women, nursing women, and children under six: To be on the safe side, avoid tuna, shark, swordfish, king mackerel, tilefish (golden snapper), and farmed salmon and limit “safe” seafood choices to a couple of servings (12 ounces) per week. For more information: http://www.epa.gov/ost/fish/
Healthy adults: No more than 7 ounces each week of swordfish, king mackerel, and tilefish (golden bass, golden snapper) and no more than 14 ounces each week of largemouth bass, smallmouth bass, pickerel, walleye, marlin, orange roughy, grouper, red snapper, and tuna (see Sustainable Fishing below).
When eating farmed salmon, look for those raised in Chile or Washington (lower PCB levels). You can also reduce your exposure to PCBs by trimming the fat from farmed salmon before cooking. Eat farmed salmon no more than 1-2 times per month.
The best omega-3 fish to eat, given all of the considerations, are: wild salmon (includes canned salmon), sardines, anchovies, and young tuna. Most tuna sold in stores today ranges in age from 6 12 years. Older fish store higher levels of mercury. Low mercury tuna (4-year-old) or minimal mercury tuna (3-year-old tuna) is available online at: http://1wildplanet.com/osCommerce/catalog/
A key benefit of omega-3 fats is to reduce inflammation. Other ways to reduce inflammation in the body are: 1) Choose healthy fats (avocado, nuts, seeds, extra-virgin olive oil), 2) Reduce omega 6s (vegetable oil, safflower oil, soybean oil), 3) Limit animal fats, and 4) Eat a wide variety of plant foods, including spices like ginger and turmeric.
There are non-fish dietary sources of omega 3s (omega-3 eggs, flaxseed, dark green leafy vegetables, pumpkin seeds, and walnuts). Four omega-3 eggs (see natural foods store) are equivalent to a 3.5 ounce serving of salmon.
Omega-3 supplements may be a good option for you consult with your healthcare provider. Read the label to verify that manufacturers have removed the contaminants from their product (FYI: mercury is found mostly in the muscle of fish and not the oil). Nordic Naturals makes quality fish oil supplements. Neuromins by Nature’s Way is a vegetarian source of DHA (long-chain omega-3 fat) derived from marine algae.