In a message dated 4/1/99 5:01:07 AM Central Daylight Time,
[log in to unmask] writes:


>> I am under the impression that one can get dry skin from a deficiency of
>> essential fatty acids, or other mineral/vitamin deficiencies.

Hi,

the following research by Dr. John McDougall, M.D., a highly reputable
Vegetarian physician, should help allay your fears about the best source
of EFA's:

Gerry
******
ESSENTIAL FATS
Only plants can create two types of polyunsaturated fats called
essential fatty acids (FE) known as omega-3 and omega-6 fats (w-3 and
w-6 fats). They are considered essential because we cannot make either
so both must be present in our foods. All other fatty acids can be
synthesized by man from any excess of dietary energy. However, just
because other fatty acids are considered unessential because we can make
them does not mean they are unimportant. For example, arachidonic acid,
derived from linoleic acid, is the major precursor for those very
important and powerful hormones, known as eicosanoids. Linoleic acid is
the most common kind of w-6 fat consumed by people. Another w-6 fat
often talked about is gamma linolenic acid. Alpha linolenic acid is
the most common w-3 fat consumed. Eicosapentaenoic acid is an w-3 fat
made from alpha linolenic acid and found in large concentrations in fish
oils. Linoleic acid is found mainly in vegetable seed oils, and the main
dietary source of alpha linolenic acid is leaves and some seeds.
There are three important functions of EFA:
1) The most important is as part of phospholipids in all animal cellular
membranes--a deficiency of EFA results in the formation of faulty membranes.
2) A second is the transport and oxidation of cholesterol; as a result
EFA tend to lower plasma cholesterol.
3) A third function is as precursors of tiny, but powerful hormones,
known as eicosanoids (prostaglandins, leukotrienes, and thromboxanes),
which are only formed from EFA.

EFA DEFICIENCY
Deficiency of EFA in experimental animals causes lesions mainly
attributable  to faulty cellular membranes, such as sudden failure of
growth, scaliness of the skin, increased water loss by a change of skin
permeability, impaired fertility, kidney abnormalities, increased
susceptibility to infection, and weaknesses in the cardiovascular
system. In man, pure deficiency of EFA has been studied mostly in
persons fed intravenously. However, sensitive tests have found
deficiencies in elderly patients, people with fat malabsorption
diseases, and after serious accidents or burns. EFA deficiency does not
occur in people following low-fat diets, because these diets are high in
vegetable foods, rich in EFA.
Through the intake of large amounts of animal products, hydrogenation of
vegetable oils, milling, and selection of w-3 poor foods, we have been
systematically depleting our intake of EFA. A relative deficiency is
also caused by large intakes of saturated animal fats and synthetic
trans fats (as found in margarine and shortenings) common in Western
diets. This deficiency of EFA plays an important part in the causation
of atherosclerosis, coronary thrombosis, multiple sclerosis,
complications of diabetes mellitus,
hypertension, and certain forms of cancer.

EFA REQUIREMENTS
Feeding diets containing as little as 0.1 to 0.5% of the calories as
linoleic acid is sufficient to correct all signs of essential fatty acid
deficiency. However, for optimal health higher intakes are recommended.
Various factors affect the dietary requirement of EFA. Animal
experiments and epidemiological studies lead to a recommendation that
the intake of w-6 linoleic acid should be decreased to as low as 2-4 %
of the calories and that of w-3 fats be increased to levels higher than
w-6 linoleic acid for the prevention of chronic diseases prevailing in
the industrialized countries (Proc Soc Exp Biol Med 200:174, 1992).

Since plants synthesize these fats they are the original and obvious
source of all EFA. If animals, say fish, have significant amounts of EFA
in their tissues it is because they ate plants, like algae, which
originally made the EFA. Natural oils contain combinations of varying
amounts of both w-6 and w-3 fats, as well as several saturated and
monounsaturated fats. Essential fatty acids are found in significant
amounts in various plants: