Thu, 15 Jan 2004 11:25:05 -0800 in article
<[email hidden]> Pete <[email hidden]>
Quoted message said:Matti Narkia said:Wed, 14 Jan 2004 21:56:43 GMT in article <[email hidden]> Ann B.
Quoted message said:I 've taken to using fish oil capsules instead of prescription anti-inflammatories when I need it
(don't want to go the Vioxx route!), but am now concerned about the levels of dioxins & other
pollutants in these capsules. I assume they're made from farmed fish, and as the oil is
concentrated, wouldn't the pollutant content also be high? The recent report on contaminated
slamon got me wondering if maybe I'd be better off not taking the 'natural' solution.
Any knowledgable comments/information on this appreciated!
Compared with fish, fish oil, especially the concentrated fish oil, has very low level of
environmental contaminants.
Any references give numbers for how safe?
Fish oil contains negligible amounts of mercury. As for other contaminant, if you want to believe
commercial hype, you should by concentrated pharmaceutical grade fish oil, which has gone through
both molecular and fractional distillation processes. I found nothing about these distillation
processes in the context of fish oil from Medline, but for whatever it's worth, many commercial
sites are keen to boast about these processes.
Medline references:
Foran SE, Flood JG, Lewandrowski KB. Measurement of mercury levels in concentrated over-the-counter
fish oil preparations: is fish oil healthier than fish? Arch Pathol Lab Med. 2003 Dec; 127(12): 1603-
5. <URL:http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14632570&dop-
t=Abstract>
"... The fish oil brands examined in this manuscript have negligible amounts of mercury and may
provide a safer alternative to fish consumption. ..."
Koller H, Luley C, Klein B, Baum H, Biesalski HK. [Contaminating substances in 22 over-the-counter
fish oil and cod liver oil preparations: cholesterol, heavy metals and vitamin A] Z Ernahrungswiss.
1989 Mar;28(1):76-83. German. PMID: 2718527 [PubMed - indexed for MEDLINE] <ncbi.nlm.nih-ncbi.nlm.nih-Open ↗
.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2718527&dopt=Abstract>
"Fish oil capsules are increasingly used by self-medicating patients. We studied 22 commercial
fish oil and menhaden oil preparations in respect to accompanying substances that could be
harmful. The substances measured were: cholesterol as determined by gas liquid chromatography,
heavy metals measured by atomic absorption, and vitamin A as determined by high-performance
liquid chromatography (HPLC). The contents of cholesterol and heavy metals were in ranges which
can be regarded as negligible; the content of vitamin A in menhaden oils, however, was found in
amounts which warrant that pregnant women do not exceed the dosage as recommended by the
manufacturers."
van de Ven WS. Mercury and selenium in cod-liver oil. Clin Toxicol. 1978;12(5):579-81. PMID: 679643
[PubMed - indexed for MEDLINE] <ncbi.nlm.nih.govquery.fcgiOpen ↗
d&list_uids=679643&dopt=Abstract>
"Cod-liver oil preparations were analyzed for mercury and selenium. The conclusion can be
drawn that the intake of mercury and selenium in the normal use of these preparations will be
very low."
Jacobs MN, Covaci A, Schepens P. Investigation of selected persistent organic pollutants in farmed
Atlantic salmon (Salmo salar), salmon aquaculture feed, and fish oil components of the feed. Environ
Sci Technol. 2002 Jul 1; 36(13): 2797-805 <URL:http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Re-
trieve&db=PubMed&list_uids=12144249&dopt=Abstract>
Hilbert G, Lillemark L, Balchen S, Hojskov CS. Reduction of organochlorine contaminants from fish
oil during refining. Chemosphere. 1998 Sep; 37(7): 1241-52. <URL:http://www.ncbi.nlm.nih.gov/entrez-
/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9734319&dopt=Abstract>
Jimenez B, Wright C, Kelly M, Startin JR. Levels of PCDDs, PCDFs and non-ortho PCBs in dietary
supplement fish oil obtained in Spain. Chemosphere. 1996 Feb; 32(3): 461-7. <URL:http://www.ncbi.nl-
m.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8907223&dopt=Abstract>
Commercial sites:
Impurities in fish oil <URL:http://www.iherb.com/mercury.html>
"... Molecular distillation is the only method (currently) that can remove metals, pcbs and
other toxins to below detectable levels for human consumption. ..."
<URL:http://news.drsears.com/archives/july/omega3.htm>
"... Some manufacturers have relied on "molecular distillation" as a touch-up process to remove
a small proportion of these contaminants. Although this is an improved "clean-up" step,
molecular distillation does not remove all the deadly contaminants that they claim and that the
consumer is led to believe. Molecularly distilled fish oil products do not qualify as
"pharmaceutical grade" regardless of what the manufacturer says. In fact, it is the crude
starting material for the production of OmegaRx. Additional and costly processing is then
required to guarantee that contaminants and saturated fats have been substantially removed from
the oil. This can only be done by a complex engineering process known as "fractional
distillation," the only guarantee that you are consuming "pharmaceutical-grade" oils. If a fish
oil product does not undergo fractional distillation, then it still contains relatively high
levels of toxins. ..."
--
Matti Narkia
