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Brought to you by Deepak Chopra, MD, Alexander Tsiaras, and TheVisualMD.com Brought to you by Deepak Chopra, MD, Alexander Tsiaras, and TheVisualMD.com
When you order fish in a restaurant these days, you might feel you need a marine biologist to help you make your selection rather than a waiter. Figuring out which fish is safe to eat -- and how often you should eat fish -- has become fraught with worry, mainly due to concerns about mercury content. You might be tempted to swear off seafood completely to keep things simple. But if you do, you'll miss out on the health benefits of eating fish, including the heart-healthy omega-3 fatty acids in many fish. A wiser approach is to understand why mercury is a concern and when to avoid certain seafood.
Where the mercury comes from How does mercury get into fish and shellfish in the first place? Mercury is a metal that occurs naturally in several forms. The kind inside your thermometer is called elemental or metal mercury. It's used to make dental fillings and some batteries. It's also used in chemical manufacturing plants, coal burning plants and other industries, and that's how it ends up in your swordfish steak. Industrial pollution releases elemental mercury into the air. Rain then washes the mercury out of the air and into streams and oceans where it gets turned into methylmercury. Fish and shellfish absorb methylmercury as they feed and it builds up in the animals' tissues over time. That's why larger and older fish tend to have the most mercury.
Risks to the developing nervous system Most of our exposure to mercury comes from the methylmercury in contaminated fish. Ingesting excessive amounts of mercury is not good for anyone. In adults, it can cause damage to the nervous system, as well as the immune system and heart. But the greatest health risk from the mercury in seafood is to fetuses, infants and very young children. Even small amounts of mercury in a pregnant or nursing woman's blood can damage the developing nervous system of a fetus or infant. Nerve cells multiply and grow at a rapid rate during gestation and infancy and are especially sensitive to mercury. Scientists aren't sure exactly how the metal does its damage, but they think that it may stop the growth of dendrites and axons, the fibers on the cells that deliver and receive signals. Studies of populations that consume large amounts of seafood have found that children who were exposed to methylmercury in the womb or shortly after birth had altered memory, attention and language development.
So how much mercury is too much? Scientists don't know precisely what level of mercury in the blood leads to harmful effects. Studies show that children suffer developmental delays when their mother's blood level is as low as 30 to 40 ng/mL (nanograms per milliliter), while adults usually don't show symptoms of mercury poisoning until their levels are higher. Fortunately, most people have some built-in protection against mercury: A genetically determined mechanism causes the body to expel the metal in 30 to 40 days. A Swedish biologist recently discovered that a small portion of the population carries a genetic mutation that makes their cells retain mercury much longer -- in rare cases up to 190 days -- and those people may be at higher risk.
While mercury poisoning from eating seafood is relatively rare, the early signs include tingling and numbness in fingers and toes and poor muscle coordination. The treatment for mercury poisoning caused by eating contaminated fish is simple: You stop eating the fish and wait for levels to come down naturally.
Guidelines for eating seafood Of course a better solution is to avoid ingesting too much mercury in the first place. That's easy to do. For most adults, eating fish and shellfish is not a health risk -- and it's important to get the health benefits of fish. Seafood is an excellent source of high-quality protein and iron, and it's low in saturated fat. And fish that are high in omega-3 fatty acids, such as trout, salmon and tuna, can lower your risk of heart attack and other cardiovascular problems. That's why the American Heart Association recommends eating at least two servings of fish a week.
However, women who may become pregnant or are already pregnant, nursing mothers and young children need to be more careful. The FDA advises pregnant or nursing women to avoid four fish that contain high levels of mercury: shark, swordfish, king mackerel and tilefish. Instead, they should eat up to 12 ounces a week of fish and shellfish that are lower in mercury. These include shrimp, canned light tuna, salmon, Pollock and catfish. If you eat canned albacore ("white") tuna, limit your intake to 6 ounces per week because it has higher mercury content. Young children should eat smaller portions of these fish.
While pregnant and nursing women should avoid high-mercury fish, they should not stop eating seafood, according to the FDA and others. That's because fish and shellfish contains nutrients that are important for a baby's growth. Plus, the omega-3 fatty acids in many fish can actually promote the baby's brain development (they help adult brains function better, too). So next time you're ordering fish, don't panic. Just make sure you eat a variety of seafood (not a steady diet of the four high-mercury fish) and follow the guidelines if you are pregnant or nursing.
Learn more about limiting your exposure to environmental toxins:
TheVisualMD.com: Environmental toxins & free radicals
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Kathryn Maroun: Mislabeled Fish Shows Seafood Industry's Floundering Conscience
I just saw you on the dylan ratign show...you are so full of sh** it's incredible you can think normal thinking Humans will swallow your BS...man....you are one piece of work...
This inforation explains so much about why some people get disease from heavy metals and chemicals in the environment. Thank you so much.
just get a good medical book
and talking of books....
try a REAL science , it may be compilicated, but stick with it...you'll see this chopra guy is full of it.
I now avoid all fish, seafood, fish oils, seaweeds and basically anything out of any ocean.
At just 19, I have severe mercury poisoning, gliosis of the brain and nerve damage.
Not that I pity myself in any way, because it was always my choice to consume fish, seaweeds, and sea foods.
However, I do strongly sympathise with the fish and sea creatures that are swimming around in excessive levels of toxic poison, as I believe, unlike us humans, they do not have a choice.
Thanks again xx
What's your evidence for this? The system that expresses proteins that mind and remove mercury depends on the presence of mercury to remain active. Not having any present would result in a significant reduction in mercury-binding proteins. Then, when experiencing an acute exposure, it will take longer to remove the mercury.
"the amount of mercury in food we eat is increasing, not decreasing,"
Reference?
"It's all about the money"
Oh, of course.
The 2 great sources are chia seeds and flaxseeds. But whole flaxseeds (tiny seeds) are not digestable. So they are sold ground but you have to be concerned about them going rancid. But the chia seeds are digestable whole and are also a source high in many other nutrients. They were used by Aztecs. But then there is an issue of the body changing the short chains of omega-3, in plant foods, into the long chains of EPA and DHA.
We need the EPA and DHA but the body is not very efficient in changing the short chains into the long chained ones that are in the fish. Fish get their omega-3 from eating algae. Two edible algaes are spirulina and Lake Klamath blue-green algae. http://bit.ly/nbD3Jx Vegans can eat them since they are not animal foods. They contain the long chains of EPA and DHA. They are called super foods since they are the most nutrient dense foods on the planet with more vitamin B-12 than liver, more calcium than milk and more beta-carotene than carrots.
Also one group found that meat was not a good source of vitamin B-12 because it increased the need for it. But a supplement of vitamin B-12 is very cheap. Some people take a 500 mg supplement of vitamin C daily. That much B-12 will last you over 100 years! You only need 6/1000 mg per day of B-12 or 6 micrograms. My mother ate lots of meat but needed a doctor to give her a needle of B-12 every week. The body can store B-12 for years unlike other vitamins.
Regarding the flaxseed, you can buy it whole, process it at home, and keep the ground seeds in the freezer.
Thanks for this article. I actually had mercury poisoning when I lived in NYC. My doctor attributed it to eating way too much sushi and tunafish sandwiches. I stopped eating fish for a year, and my levels went down. I'm now a bit paranoid about eating fish, and take high quality fish oil supplement insstead.
Since I love fish, this article makes me feel that I can still enjoy this excellent source of protein and oils, as long as I stick to a variety of species instead of just tuna!
Salmon, halibut, trout, bass, etc. are all on the menu.
I've tried to determine this via google, but to no avail.
i hate to feed meat. fish... to my pets ,,,,,,but i have to.
.
Go Vegan !
I have no problem with vegans or vegetarians, and I understand some of the reasons for this way of life. I actually thought about being vegetarian at one point myself.
Not to mention their reliance on others in society that eat meat.
It's nice to live in a country, in a time where you can pick and choose what you eat. Trying to project some moral high-ground is out of line.
http://people.uwec.edu/piercech/hg/mercury_tox/distributionexcretion.htm
http://www.ead.anl.gov/pub/doc/mercury.pdf
Now can you please explain if there is a health risk or benefit to wild versus farm raised fish?
Thanks so much.
Carolyn Winter
Studies in British Columbia and UK showed farmed salmon accumulate more cancer-causing PCBs and toxic dioxins than wild salmon.
Flame-retardant additives used widely in electronics and furniture are appearing in increasing amounts in fish, and farmed salmon contain significantly higher levels of these polybrominated diphenyl ether (PBDE) compounds than wild salmon.
In the wild, salmon absorb carotenoids from eating pink krill. On the aquafarm, their rich pink hue is supplied by canthaxanthin, a synthetic pigment manufactured by Hoffman-La Roche.
Aquafarms, called "floating pig farms," by Daniel Pauly, professor of fisheries at the University of British Columbia in Vancouver, put a significant strain upon their surrounding environment. According to Pauly, "They consume a tremendous amount of highly concentrated protein pellets and they make a terrific mess."
U.S. farmed cobia, catfish, freshwater prawns, and numerous other species are all safe to eat and sustainable. Also, not all farmed salmon is bad; there are some (small-scale) closed systems that are ecologically sound and produce fish that are safe to eat.