>Jean-Louis, what was it about borage oil that Sears found undesirable?

He doesn't find it undesirable, but it just didn't meet his expectations.
Basically, there is a chain of reactions of omega 6s like this:

                  "good" eicosanoids
                 /
LA -> GLA -> DGLA
                 \
                  Arachidonic acid -> "bad" eicosanoids

Sears says that the transformation LA -> GLA is inhibited by an excess of
ALA (Alpha-linolenic), so he is not for the use of flax seed.

GLA is present in breast milk, and in borage oil.

The transformation DGLA -> AA is inhibited by EPA. So, Sears thought that
you could reach "The Zone" by supplementing with borage oil and fish (or
fish oil), but he got inconsistent results. He discovered then that the
reaction DGLA -> AA was activated by insulin and inhibited by glucagon, so
he came to think that it was best to regulate the amount of carbohydrate,
protein, etc.

> Also, USDA data suggest other foods than flax have alpha-linoleic
> acid, and some veg foods seem to have EPA and DHA as well.

Yes, walnut is a good source of polyunsaturated fatty acids (other nuts
contain more monounsaturated), but contains much more LA (linoleic) than
ALA, i.e. the ratio omega3/omega6 is too low (balance between omega 3s and
omega 6s is probably important).

I don't know which veg foods contain EPA and DHA, but the tables in
Rudin's book ("omega 3 oils"), fatty veg foods (nuts...) give "0" (or
perhaps tracial amounts only). I'll have to check that.

Jean-Louis
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