Are you up to date with the dangers of mercury in fish? With all the buzz about the amazing benefits of omega-3 fatty acids, many people are making fish a bigger part of their diets. But the fact that nearly all fish and shellfish contain mercury has most of us questioning whether or not it’s a good health choice.
Benefits of Eating Fish
Besides being low in saturated fat and containing protein and other nutrients, the Omega-3 fatty acids in fish have been shown to help cholesterol levels, heart health, and childhood development. Including fish in the diet can improve rheumatoid arthritis, neurological issues, depression, and type 2 diabetes.
Hazards of Mercury
After mercury is pumped out of industrial plants, it falls from the air into the oceans, lakes and rivers. Once in water, bacteria converts it into methyl mercury, a form easily absorbed by humans. It rests in the fish, accumulating at greater levels as bigger fish eat smaller fish until they get to us.
The health risks are especially dangerous for pregnant women and small children, as mercury acts as a neurotoxin, harming the brain and nervous system. It can also lead to blindness, deafness, cerebral palsy and other developmental issues. For everyone, it has been shown to have adverse effects on the heart, blood pressure, fertility, and can contribute to hypertension, heart disease, memory loss, tremors and numbness of the extremities.
And as if mercury poisoning weren’t enough, other contaminants have been found in fish, such as PCBs, Chlordane, Dioxins, DDT, pesticides and heavy metals.
Wild versus Farmed Fish
Many people are looking to farmed fish to allay the mercury contamination issue. It’s hard to say if this will make a difference, because lots of studies are showing other kinds of contamination in farmed livestock. A 2003 study by the Environmental Working Group found that U.S. farmed salmon contained extremely high levels of PCBs, which comes from the fish meal the salmon are fed.
Another toxin is malachite green, a fabric dye used as a fungicide and parasiticide. Considered a carcinogen, it has been linked to liver and lung issues, but definitive evidence has yet to be published.
The EPA and FDA have published guidelines to help consumers through this difficult issue. At this point in time, we are urged to still include fish in our diets (though many vegans know better than to listen to the FDA), but to watch a few factors.
- Fish to avoid are shark, swordfish, king mackerel and tilefish.
- Fish to limit: tuna, especially white albacore tuna and tuna steak, as they have higher mercury levels than chunk light tuna.
- Safer fish include: shrimp, salmon, pollock and catfish.
- Check local advisories about area farms, rivers, lakes and coasts to make sure levels are safe.
- The EPA publishes local Fishing Regulations Booklets to ensure safe fishing.
- Normal adults can safely eat up to 12 oz. of low risk fish a week, 6 oz. for the riskier ones. Children, pregnant women, or women wishing to become pregnant should significantly limit the amounts of fish they consume, avoiding those higher in mercury levels.
The good news is that methyl mercury is removed by the body naturally, but it does take a long time, perhaps a year or longer. Watch the levels and amounts consumed for the healthiest path on this murky food road.