Fish Oil Supplements May Be Safer Than Eating Fish

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http://www.medscape.com/viewarticle/498364_print

Jan. 28, 2005 - Fish oil supplements may be safer than eating fish, at least

from the standpoint of toxic impurities, according to the results of a study

published in the January issue of the Archives of Pathology and Laboratory

Medicine.

" The consumption of fish high in omega-3 fatty acids is advocated by the

American Heart Association to decrease the risk of coronary artery disease, "

write Foran Melanson, MD, PhD, from the Brigham and Women's Hospital

and Harvard Medical School in Boston, Massachusetts, and colleagues.

" However, fish contain environmental toxins such as mercury, polychlorinated

biphenyls, and organochlorine [OC] pesticides, which may negate the

beneficial cardiovascular effects of fish meals. "

OC analysis of the contents of five commercial fish oil brands revealed that

the levels of polychlorinated biphenyls (PCBs) and OCs were all below the

detectable limit.

" Fish oil supplements are more healthful than the consumption of fish high

in organochlorines, " the authors write. " Fish oils provide the benefits of

omega-3 fatty acids without the risk of toxicity. In addition, fish oil

supplements have been helpful in a variety of diseases, including bipolar

disorder and depression. "

The authors note that of the PCBs produced in the U.S. before 1976, 1.2

billion pounds entered rivers, lakes, and oceans, where they accumulate in

bottom-feeding fish and become more concentrated higher up on the food chain

(0.6-20 parts per million [ppm] in edible fish high in the food chain). In

1984, the Food and Drug Administration (FDA) lowered the limit to 2.0 ppm

for edible fish.

Similarly, OC pesticides entered the air, water, and soil when they were

sprayed on crops and forests and concentrate more than 1,000-fold in fish

and marine mammals. These pesticides, including DDT, were banned in 1973

because of their neurotoxic properties.

Although consumption of 200 to 400 g of oily fish each week has been

recommended to protect against cardiovascular disease, regular fish intake

presents potential problems, particularly in children and pregnant women.

The authors estimate that compared with fish oil supplementation, regular

consumption of fish from the Great Lakes would expose humans to at least 70

times more PCBs and 120 times more OC pesticides.

" Our data concerning the levels of OCs suggest that fish oil supplements may

be preferable to fish consumption as a dietary guideline for the general

population and as a therapeutic source of omega-3 fatty acids in patients

with cardiovascular disease and depression, " the authors conclude.

The authors report no relevant financial interests.

Arch Pathol Lab Med. 2005;129:74-77