Phosphor wrote:
>>20:5 (EPA) and 22:6 (DHA).. linolenic omega ...
>Any comment on whether these three are sufficientlysimilar to lump them
together
> its a travesty of the truth, since it is EPA and DHA [and also DPA] which
> are the essential fatty acids.  linolenic is not.

There are only *two* essential fatty acids,
LA, 18:2 (omega-6) and
LNA, 18:3 (omega-3)

All other fatty acids, may they be in the omega-3 or omega-6 pathway,
are not essential. The body can all other fatty acids other the two
above, so they are not essential like vitamins are.
Here's what the body makes of the two:
http://www.zonehome.com/images/efa.gif (small)
or here http://benbest.com/health/essfat.html (thorough)
and in zillions of other books and publications.

> our ability to convert is
> limited and unsatisafactory.

This is the supposition of one single study which was made seemingly
without the knowledge of the factors that hinder the conversion
pathways.
As are
trans-fatty acids,
alcohol,
excess omega-6 intake
excess OA (oleic acid) intake
and some vitamin and mineral deficiencies.

While at the same time billions of humans with a zero intake of the
mentioned EPA and DHA have quite the same levels as those who prefer to
eat them preformed.

Amadeus Schmidt-Philipp