Inferiority of Fish Oils - Reason 1

Fish is no longer a health food.

Today, it is widely recommended that people obtain their EFAs from fish. For vegans and some vegetarians, this is not an option. Among the main problems with this advice is that all marine life has varying levels of toxins and pollutants. One of the nastiest is a class of contaminants called POPs (Persistent Organic Pollutants).1 This category consists mainly of dioxin, PCBs (polychlorinated biphenyls), and DDT. These cause a host of health problems, including reproductive difficulties, cancers, and neurological disorders. Those most at risk are ones with weakened immune systems (which include a good portion of the so-called healthy population), children, pregnant women, and the elderly.

Dioxins and PCBs are two of the twelve2 most dangerous chemicals known to man because, not only are they toxic, persistent, and bio-accumulative, but they can also be carried long distances in air currents, thereby posing a threat to humans and wildlife living in remote places once thought to be safe. Because they are also fat soluble, oily fish and fish oil supplements can be rich sources of POPs. These toxic chemicals, along with heavy metals, are especially concentrated in the livers of fish – an important fact to consider if taking fish liver oil supplements. It is no secret now that people who regularly consume fish will have larger levels of toxic chemicals in their bodies than those who eat fish only occasionally or who do not consume it at all.

Another chemical of concern is mercury.3 Although it occurs naturally in the environment, most is released by incineration and coal-burning power plants and by mining and industrial processes. In the US alone, more than 40 tons of mercury are released into the air every year, eventually ending up in water where it changes into a form called methyl mercury, which accumulates in fish as they grow older and bigger. Fish that tend to have high levels of POPs in their bodies are also ones more susceptible to accumulations of mercury.

Women in coastal areas have higher levels of mercury than those who live inland.4 Ironically, pregnant women are told to eat more fish to obtain valuable omega-3 fatty acids for their unborn child. By doing this, however, they are exposing greater risk to their fetuses. Fetal exposure to mercury can cause learning deficits and other neurological problems. This is not an isolated problem occurring in the far north. It is estimated that a full 10% of American women (about 7 million) have mercury levels above what is considered to be average. Despite these findings, fish is still being recommended – but in smaller doses.5

Significant amounts of EFAs are found only in ocean fish that have eaten plankton rich in ALA. This does not apply to farmed fish, which are fed various high protein concentrates. According to Professor Frank Hu, who conducted a 16-year study on omega-3 fatty acids and heart disease in women, farmed fish hardly contains any omega-3s at all.6 In addition, because of pollutants, some researchers advise that consuming more than one meal of farmed fish every month or two increases the risk of cancer.7, 8

As if that wasn’t bad enough, farmed fish may also contain flame retardants. Although these have been found mainly in cod liver oil, farmed fish (including European salmon) that are given feed containing liver oils are more likely to have PBDEs (polybrominated diphenyl ethers). PBDEs are showing up in a wide variety of unusual places such as human breast milk in the United States and peregrine falcon eggs in Sweden. Fish oils are also used as feed supplements for farm animals, including sheep, cows, and chickens.9

Additional studies have shown a paradox concerning the elderly who are encouraged to eat fish. Research found that, while an increased consumption of fish was associated with a decreased risk of late age-related maculopathy (ARM), it did interfere with the absorption of vitamin E,10 one very necessary in reducing risk of several disorders, including visual disturbances.11, 12, 13

To be sure, contaminants are also found in plant foods. This is why it is so important to obtain organic foods14 whenever possible. While organic produce may not be available in all areas, it does present reason enough for people to make every effort to have them grown in their communities and brought into their stores. Until then, consume more foods that contain the least amount of contaminants (found at the bottom of the page).

Aside from contaminants, fish is being recognized as a major food and occupational allergen. Reactions to fish are among the most common food allergies found in adults and children.15, 16, 17, 18, 19, 20, 21 But fish is not always obvious. Fish can be found in such items as Worcestershire sauce, which may contain anchovies, Caesar salad, and imitation seafood.22

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Other References

This page was updated in December 2005.