Re: Lowest Omega-6 Oil?

On 14 Apr 2007 08:52:32 -0700, "Ron Peterson" <ron@xxxxxxxxxxxxxx>
wrote:

On Apr 10, 4:19 pm, Matti Narkia <m...@xxxxxxxx> wrote:

Remember though that olive oil has hardly any omega-3 and that omega-3
in rapeseed oil is alpha-linolenic acid, which humans cannot convert
very efficiently to longer chain omega-3 EPA and DHA. Therefore to
improve your omega-3/omega-6 -ratio you also need to eat some fatty
fish or/and take fish oil.

Yes, ALA isn't converted to EPA and DHA efficiently, but
http://www.poultryscience.org/ps/paperpdfs/00/ps00961.pdf indicates
that ALA does function as a moderator for omega 6 fatty acids.

It says:
"The presence of ALA in the diet can inhibit the conversion of the
large amounts of LA in the
diets of Western industrialized countries that contain too
much dietary plant oils rich in n-6 PUFA (e.g., corn, safflower,
and soybean oils). The increase of ALA, together
with EPA and DHA, and reduction of vegetable oils with
high LA content are necessary to achieve a healthier diet
in these countries."

EPA also inhibits conversion of LA to arachidonic acid (ARA), because
it inhibits the enzyme delta-5-desaturase needed in one step of that
conversion, see the references below. EPA also competes with ARA from
the enzymes COX-2 and 5-LOX, and therefore reduces production of
inflammation mediators from ARA.

I'm a guy, the majority of guys will have latent prostate cancer, if
they live long enough, and evidence from epidemiological studies and
animals tests suggest that ALA may accelerate growth of an existing
prostate cancer. Therefore I try to avoid getting too much ALA, if I
can, because EPA alone can do fairly good job in inhibiting conversion
of LA to ARA _and_ in inhibiting production of inflammation mediators
from ARA.

References:

Barham JB, Edens MB, Fonteh AN, Johnson MM, Easter L, Chilton FH.
Addition of eicosapentaenoic acid to gamma-linolenic acid-supplemented
diets prevents serum arachidonic acid accumulation in humans.
J Nutr. 2000 Aug;130(8):1925-31.
PMID: 10917903 [PubMed - indexed for MEDLINE]
<http://www.nutrition.org/cgi/content/full/130/8/1925>

Rubin D, Laposata M.
Cellular interactions between n-6 and n-3 fatty acids: a mass analysis
of fatty acid elongation/desaturation, distribution among complex
lipids, and conversion to eicosanoids.
J Lipid Res. 1992 Oct;33(10):1431-40.
PMID: 1472257 [PubMed - indexed for MEDLINE]
<http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1472257&dopt=Abstract>

Umeda-Sawada R, Takahashi N, Igarashi O.
Interaction of sesamin and eicosapentaenoic acid against delta 5
desaturation and n-6/n-3 ratio of essential fatty acids in rat.
Biosci Biotechnol Biochem. 1995 Dec;59(12):2268-73.
PMID: 8611750 [PubMed - indexed for MEDLINE]
<http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8611750>

Umeda-Sawada R, Ogawa M, Igarashi O.
The metabolism and n-6/n-3 ratio of essential fatty acids in rats:
effect of dietary arachidonic acid and a mixture of sesame lignans
(sesamin and episesamin).
Lipids. 1998 Jun;33(6):567-72.
PMID: 9655371 [PubMed - indexed for MEDLINE]
<http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9655371>


--
Matti Narkia
.

Relevant Pages

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