Fishing for the Truth

Michael Hawthorne and Sam Roe of the Chicago Tribune report that the United States safety net for safeguarding consumers against the increased mercury levels in fish is in tatters. In the article the reporters detail the fate of one particular piece of fish:

Shipped from Singapore, the swordfish entered the U.S. this year without being tested for the toxic metal mercury.

When a fillet from that fish reached a display case at a supermarket in suburban Des Plaines, it carried no government warning labels, even though federal officials know swordfish often is so contaminated that young children and pregnant women should never eat it.

The Chicago Tribune actually bought and tested a portion of this fish, which produced alarming results:

When the Tribune bought and tested this particular piece of fish, the results showed not just high amounts of mercury, but levels three times the legal limit.

Hawthorne and Roe point out the dangers lurking in the fish and in the actions of U.S. health officials:

Even though mercury can cause learning disabilities in children and neurological problems in adults, regulators do not even bother to routinely check fish for metal. This leaves consumers with little idea about which fish are most hazardous.

In some cases, regulators have ignored the advice of their own scientists who concluded that mercury was far more dangerous than what consumers were being told.

In other instances, regulators have made decisions that benefited the fishing industry at the expense of public health.

In his book Eat to Live Dr. Fuhrman explains that consumption of fish creates a parodox:

Fish contains omega-3 fatty acids (EPA and DHA) that interfere with blood clotting much the same way aspirin does. Once you have significant atherosclerosis, it is helpful to take such anti-clotting agents, especially if you continue a dangerous diet. These fish derived-fats also have some effect on protecting the arterial walls from damage from other fats.

However, the best way to prevent a heart attack or stroke is to follow a high-nutrient diet with little or no animal products, thereby ensuring that such blockages don't develop in the first place. Then eating fish won't matter. In fact, the reason fish-derived fats, EPA and DHA, are not considered essential fats is that almost all people have enzymes to convert the plant-derived omega-3 fat rapidly into EPA and DHA.1

Fish is a double-edged sword, especially because fish has been shown to increase heart attack risk if polluted with mercury.2 It seems that the cardioprotective effects of eating a little fish is lost when you eat lots of fish, most likely because lots of fish exposes you to high mercury levels, which can promote lipid peroxidation.3 Lipid peroxidation plays a major role in the development of diseases such as heart disease, diabetes, and arthritis.

Dr. Fuhrman provides important information to consider when deciding whether or not to consume fish:

Higher levels of mercury found in mothers who eat more fish have been associated with birth defects, seizures, mental retardation, developmental disabilities, and cerebral palsy.4 This is mostly the result of women having eaten fish when they were pregnant. Scientists believe that fetuses are much more sensitive to mercury exposure than adults, although adults do suffer from varying degrees of brain damage from fish consumption.5 Even the FDA, which normally ignores reports on the dangers of our dangerous food practices, acknowledges that large fish such as shark, swordfish, and yellowfin and bluefin tuna, are potentially dangerous. Researchers are also concerned about other toxins concentrated in fish that can cause brain damage way before the cancers caused by chemical-carrying fish appear.

Fish with Highest and Lowest Mercury Levels

Highest
  • tilefish
  • swordfish
  • mackerel
  • shark
  • white snapper
  • tuna

Lowest
  • salmon
  • flounder
  • sole
  • tilapia
  • trout

Source: Mercury levels in seafood species. U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition. Office of Seafood, May 2001.

The bottom line: Choose fish over other animal products, but be aware that the place where it was caught, and the type of fish, matters. Don't accept recreational fish from questionable waters. Farmed fish is safer. Never eat high-mercury-content fish. Don't eat fish more than twice a week, and if you have a family history of hemorrhagic stroke, limit it further to only once a month.

1. Siguel, E.N., and M. Macture. 1987. Relative enzyme activity of unsaturated fatty acid metabolic pathways in humans. Metabolism 36: 664-69

2. Salonen, J. T., K. Seppanen, K. Nyyssonen, et al. 1995. Intake of mercury from fish, lipid peroxidation, and the risk of myocardial infarcation and coronary, cardiovascular, and any death in eastern Finnish men. Circulation 91: 645-55.

3. Salonen, op. cit.

4. Shamlaye, C. F., D. O. Marsh, G. J. Myers, et al. 1995. The Seychelles Child Development Study on neurodevelopmental outcomes in children following in utero exposure to methylmercury from a maternal fish diet: background and demographics. Neurotoxicology 16 (4): 597-612; Rylander L., U. Stromberg, and L. Hagmar. 1996. Dietary intake of fish contaminated with persistent organochlorine compounds in relation to low birthweight. Scand. J. Work Environ. Health 2 (4): 260-66; Does methylmercury have a role in causing developmental disabilities in children? 2000. Environ. Health Perspect. 108 (supp.3): 413-20.

 5. Clarkson, T.W. 1997. The toxicology of mercury. Crit. Rev. Clin. Lab. Sci. 34(4):369-403.


 




Trackbacks (0) Links to blogs that reference this article Trackback URL
Comments (2) Read through and enter the discussion with the form at the end
Henry Abbott - December 22, 2005 3:59 PM

Here's an interesting little device: http://www.gotmercury.org/

It's a calculator that lets you put in your weight, which kind of fish you intend to eat, and in what quantity. Then it tells you what percentage of the EPA limit you are likely to get.

Donna - January 6, 2006 10:54 AM

Bayer made Rhogam that contained 35 mcg of mercury, Bayer in 2003

Petitioned OEHHA to take thimerosal/mercury off the list of
reproductive toxins,

Here is OEHHA reply to Bayer.

OEHHA (Office of Environmental Health Hazard Assesment) reports;

"The scientific evidence that PMA and Thimerosal cause reproductive
toxcitity is CLEAR and VOLUMINOUS.

The evidence for its reproductive toxcitity includes severe mental
retardation or malformations in human offspring who were poisoned
when thier mothers were exposed to ethylmercury or thimerosal while
pregnant."

The Flu vaccine that mothers are encouraged to get, contains 25 mcg of mercury that is injected into pregnant women.

http://www.oehha.ca.gov/prop65/CRNR_notices/pdf_zip/hgbayer1.pdf

Post A Comment / Question Use this form to add a comment to this entry.







Remember personal info?