something else interesting that i've been thinking a lot about lately is the omega 6 make up of our fats VS omega 3. Basically, the composition of animal fats is extremely dependent on the source of those fats in the animal's diet. fed a diet of grass, etc (ie, low o6, high o3), beef fat should be relatively low in o6, but given a diet of grains (high o6 and low o3) the beef fat will be very high in o6.
this is really a product of modern farming practices where grains and soy, etc are abundant and given to animals as primary food sources hence their fat make-up is skewed dramatically towards o6.
this issue also occurs with chickens - a chicken fed primarily grains containing o6 rich vegetable oils will produce eggs that are much higher in o6 than o3. hence, if you're looking at the influence of eggs on health outcomes, you not only need to look at the number of, but also the type of (ie, commercially farmed high-o6, or naturally farmed and low-o6).
we have 5 chooks in the backyard and are getting about 4 eggs a day at the moment (which i happily plow through) but up until a month ago they were on their annual winter strike and so i was largely eating shop bought eggs. I have full cholesterol numbers from a few weeks ago and a referral to go get some more in november (after 3 months of home grown, grain-free eggs) so i will be very interested to see what happens to my LDL numbers over that time...
see here for more info:
American Friends of Tel Aviv University: Can Eggs Be a Healthy Breakfast Choice?