(NaturalNews) People are becoming increasingly aware of the benefits of fish, and in particular, the need for long-chain omega-3 fatty acids in the diet. On the other hand, conscientious consumers are reckoning with serious contamination in these otherwise healthy foods. All fish, and especially large predators, are polluted with heavy metals and industrial waste products that are potentially damaging to humans who consume them. This has spawned a lively debate over whether the benefits outweigh the risks.
No doubt, fish is good for human health. It is a source of lean meat, vitamins, minerals and essential oils. The best of these (e.g., salmon, tuna, sardines, herring, trout) are packed with omega-3s, which have been shown to lower the risk of heart attack, alter immune system function, reduce serum triglyceride levels, make intelligent babies with good vision, protect the brain, relieve pain and stiffness, etc. The list truly goes on and on.
Unfortunately, most fish have some degree of chemical contamination with methylmercury and organic pollutants like dioxins, PCBs and pesticides. These chemicals have adverse effects on the nervous, immune and cardiovascular systems. Some fish are so mercury laden that eating them during pregnancy could damage fetal brain tissue. Pregnant women, those who might become pregnant and young children should avoid fish with high levels of mercury (e.g., shark, swordfish, king mackerel, tilefish), and should eat no more than two fish meals a week of any kind, according to the FDA. Moreover, albacore tuna should be limited to once a week or less.
Otherwise, current expert advice says to eat a variety of fish. Alternatively, purified fish oil can provide needed omega-3 fats to supplement the diet. Some oils (e.g., molecularly distilled, pharmaceutical-grade) are cleaner than others, and some (e.g., krill oil) are better absorbed. There are also many plant sources of omega-3, such as flax, walnuts and hemp, but many people cannot efficiently convert these short-chain omega-3 fats to the forms needed by animals.
The ideal diet contains at least some fatty fish, high-quality fish oil supplements, and nutrients that protect against mercury poisoning and environmental toxins. The list of protective nutrients starts with selenium and zinc, which can both be obtained from a good multivitamin. Zinc induces the production of metallothionein, a protein that ties up heavy metals in the gut, brain, kidney, and elsewhere in the body. Selenium is part of the glutathione detoxification system, by far the most important antioxidant and heavy metal antidote in the body. The sulfur-containing amino acid cysteine is a constituent of glutathione, and it may be obtained in supplement form from N-acetyl-cysteine. Other sulfur-containing nutrients, like methionine, taurine and garlic, also contribute to glutathione production. Another important sulfur-containing antioxidant that protects against mercury poisoning is alpha-lipoic acid. Vitamin D helps remove mercury from the body, also by increasing glutathione. Other key antioxidants that protect the brain from mercury and toxin-induced oxidative stress include vitamin E complex, especially the tocotrienols, and vitamin C complex. Furthermore, cilantro, chlorella, chlorophyll, and bentonite clay are heavy metal detoxifiers, as are commercially available detox teas and herbs. When eaten with fish, these nutrients and herbs reduce toxicity significantly.
In summary, fish provide excellent nutrition, and they are the best source of omega-3 fatty acids, despite being contaminated with toxins. The take home message is: most people should eat fish often, as long as they choose wisely and minimize toxic effects with key nutrients. Granted, there are other pressing problems with fish, such as overfishing, habitat destruction and fish farming, but that's another story all together.
References: Bushkin-Bedient S, Carpenter DO. Benefits versus risks associated with consumption of fish and other seafood. Rev Environ Health 2010;25:161-91.
Patrick L. Mercury toxicity and antioxidants: Part 1: role of glutathione and alpha-lipoic acid in the treatment of mercury toxicity. Altern Med Rev 2002;7:456-71.
About the author
Dr. Phil Domenico is a nutritional scientist and educator with a research background in biochemistry and microbiology. Formerly an infectious disease scientist, he now works as a consultant for supplement companies and the food industry.