In the last digest, Jennie wrote:

"Thank you Loren for correcting my out-of-date information.  But I'm
still
confused!  If the majority of the fatty acids eaten with meat come from
the
muscle triglcerides and subcutaneous adipose tissue, then surely the
difference in muscle phosholipid fatty acid pattern is of only limited
significance.

 Alot of work was done in Australia in the 1970's (where cattle are
mainly
pasture-fed) to increase the PUFA content by feeding the animals
'protein-protected' PUFAs.  The ruminant bacteria were not able to
hydrogenate the PUFAs because of a coating of treated protein.  The
process
worked but there was limited consumer acceptance of this 'new' meat and
its
unusual flavour.

Best wishes  Jennie"

        I would agree that the majority of fat in domestic, grain fed
cattle is derived from inter-muscular and subcutaneous triglycerides,
and that these tissues are minimally influenced by dietary lipid
manipulations.    However, in wild animals, because there is no
inter-muscular fat storage (marbling), and because subcutaneous fat
stores almost never represent more than 4% (seasonally) of  total body
wt (compared to 35-45% for grain fed cattle), the differences in muscle
phospholipid fatty acid patterns caused by free ranging foraging (as
opposed to grain feeding) represents a significant difference when
compared to domestic animals.    Obviously, the tissue phospholipid
fatty acid patterns of individuals consuming free foraging animals will
reflect this difference.
        The level of enrichment of DHA (22:6n3) by fish oil feedings in
cattle is remarkable and approaches 500%.   Mandell (1) has recently
shown an increase of DHA (mg/100 fresh wt) from 1.8 to 11.0, however, as
Jennie has pointed out, it is unclear whether this may have a real
influence upon the consumer, since the level of both DHA and EPA
(20:5n3) combined, when expressed as a percentage of total fatty acids
rose from 0.2 to 1.0, and fish oil supplementation at this level (10%)
definitely imparts a fish flavor to the meat.
        The western diet is overburdened by a high dietary n6/n3 ratio
(estimated to be about 10:1), and any attempts to influence the food
supply of the average consumer in order to improve this ratio (closer to
the estimated 2-4 to 1 in paleolithic diets) should not be discouraged.
Grass fed cattle, allowed to free forage will not only have a more
favorable fatty acid pattern in muscle and organ phospholipids, but they
will have less storage trigylcerides because of the energy expenditure
required for free foraging.  Clearly, the massive consumption of foods
high in omega 6 fats (certain vegetable oils, margarines, shortenings)
and low in omega 3 fats is vastly at odds with the fats derived from
foods available to our stone age ancestors and is associated with many
of the chronic illnesses (cardiovascular disease, cancer and
inflammatory and autoimmune diseases) which plague modern man.

                                Cordially,


                                Loren Cordain, Ph.D.
                                Professor,  ESS Dept
                                Colorado State University
                                Fort Collins, CO 80523

                                REFERENCES

1.      Mandell IB et al.  Omega-3 fatty acid enrichment of Beef. J Anim
Sci, in press.