Maximizing ALA conversion to EPA and DHA

[Guest guest]

I ran across an interesting article this evening that I thought may be

of interest to some:

Quantitation of alpha-linolenic acid elongation to eicosapentaenoic and

docosahexaenoic acid as affected by the ratio of n6/n3 fatty acids:

http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed & pubmedid=1922839\

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The paper's conclusions were as follows:

Our investigations show that exposure of human hepatocytes to different

mixtures of LA and ALA affected transcript levels of a portfolio of

genes encoding regulating proteins involved in several stages of fatty

acid metabolism. This effect strongly depends on the ratio of n6/n3

fatty acids, indicating the importance of ingesting an appropriate

amount of fatty acids, but also an appropriate ratio of n6 and n3 fatty

acids. This is further confirmed by the fact that maximum conversion of

LA to AA was measured only in the presence of ALA. Omitting ALA seems to

result in higher oxidation rates as indicated by high transcript levels

of PPAR. Additionally, the n6/n3 ratio strongly influenced the

elongation of ALA to EPA and DHA as well as the transcript levels of D5D

and D6D.

However, from a nutritional perspective, our findings suggest that a

diet-induced enhancement of the cell membrane content of highly

unsaturated fatty acids is only possible up to a certain level.

Increasing the administered quantity of labeled alpha-linolenic acid

resulted in a reduced effectiveness of [13C]ALA incorporation.

Percentage incorporation of [13C]ALA was maximal after exposure of

[13C]LA/[13C]ALA at a ratio of 4:1 to HepG2 cells.

With regard to the elongation of ALA to EPA and DHA, our results clearly

indicate the efficiency of altering the dietary ratio of LA to ALA in

favor of ALA by increasing the concentration of n3 fatty acids in human

hepatocytes. At this, administration of LA/ALA at a ratio of 1:1 led to

the highest formation of LCPUFAs of the n3 series.

Kind regards,

Nick

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