The essential polyunsaturated fats are substances our bodies cannot
make and participate in so many important bodily functions that
they deserve a place on a nutrition program's main screen alongside the essential vitamins and minerals.
NUT incorporates
an empirical equation from Dr. William Lands that relates
polyunsaturated fatty acid
consumption in a low-fat diet to resulting percentages of Omega-6 highly
unsaturated fatty acids
in tissue phospholipids
over the long term.
In a personal email exchange, Dr. Lands cautioned me that he didn't have data
that corroborated his equation for a high-fat, low-carb diet, but
my experiments have not shown any huge discrepancy between macronutrient
extremes.
The NUT reference values are refigured every time you show an analysis screen and they take into consideration all the fatty acids in
the diet.
The scatterplot at the right shows actual levels of highly unsaturated fatty
acids in tissue phospholipids for a population sample,
with the first number of the "Omega-6/3 Balance"
value indexed on the bottom axis.
The following graph is meant to demonstrate that comparable results can be
achieved by either adding Omega-3 or reducing Omega-6 in accordance with
varying cultural food customs.
The rationale is that excessive Omega-6 metabolites can cause an
exaggerated inflammation response that leads to tissue damage and
cardiovascular events which
can be prevented by allowing Omega-3 to outcompete
Omega-6 for positions in the tissue phospholipids.
The graph below shows tissue concentrations of Omega-6
highly unsaturated fatty acids
plotted against population cardiovascular mortality.
Here is a nice ecological overview book chapter by Dr. Lands for the biologically-literate. And here is an excellent and understandable review by Dr. Lands with enough depth to further your comprehension of the importance of these fatty acids to how well you feel physically and mentally.
Recently, erudite nutrition pundits have stated that we have no requirement for the short-chain fatty acids from plants, only the long-chain metabolites such as those in fish oil. In the case of Alpha-Linolenic Acid (ALA), I think there is definitely a requirement separate from the EPA and DHA in fish oil. Although ALA makes almost no difference to the Omega-6/3 balance, I notice a great improvement in my skin and hair and a better suppression of inflammation when I regularly include an ALA source such as ground flax seeds or flax oil. However, NUT does not separately compute an ALA requirement apart from the Omega-6/3 balance, so you have to experiment to find the level and source of ALA that is best.
Experiment with various "Omega-6/3 Balance" values to get the main benefit of Omega-3, which is a lack of physical and mental suffering.