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A Reply to Ray Peat
on Essential Fatty Acid Deficiency
By Mary G. Enig, PhD
Ray Peat, PhD, is an influential health writer who claims that there
is no such thing as essential fatty acid (EFA) deficiency. According
to Peat, the body can make its own EFAs; furthermore, he claims that
EFAs in the body become rancid and therefore cause cancer.
Unfortunately, Peat does not understand the use of EFA by the human
body. He is trained in hormone therapy and his training in fats and
oils has been limited to misinformation as far as the polyunsaturated
fats and oils are concerned.
Research on EFAs is voluminous and consistent: EFAs are types of fatty
acids that the body cannot make, but must obtain from food. We do not
make them because they exist in virtually all foods, and the body needs
them only in small amounts. The body does make saturated and monounsaturated
fatty acids because it needs these in large amounts and cannot count
on getting all it needs from food.
There are two types of EFAs, those of the omega-6 family and those
of the omega-3 family. The basic omega-6 fatty acid is called linoleic
acid and it contains two double bonds. It is found in virtually all
foods, but especially in nuts and seeds. The basic omega-3 fatty acid
is called linolenic acid and it contains three double bonds. It is found
in some grains (such as wheat) and nuts (such as walnuts) as well as
in eggs, organ meats and fish if these animals are raised naturally,
and in green vegetables if the plants are raised organically.
Essential fatty acids have two principal roles. The first is as a constituent
of the cell membrane. Each cell in the body is surrounded by a membrane
composed of billions of fatty acids. About half of these fatty acids
are saturated or monounsaturated to provide stability to the membrane.
The other half are polyunsaturated, mostly EFAs , which provide flexibility
and participate in a number of biochemical processes. The other vital
role for EFAs is as a precursor for prostaglandins or local tissue hormones,
which control different physiological functions including inflammation
and blood clotting.
Scientists have induced EFA deficiency in animals by feeding them
fully hydrogenated coconut oil as their only fat. (Full hydrogenation
gets rid of all the EFAs; coconut oil is used because it is the only
fat that can be fully hydrogenated and still be soft enough to eat.)
The animals developed dry coats and skin and slowly declined in health,
dying prematurely. (Interestingly, representatives of the vegetable
oil industry blame the health problems on coconut oil, not on fatty
acid deficiency!)
In a situation of fatty acid deficiency, the body tries to compensate
by producing a fatty acid called Mead acid out of the monounsaturated
oleic acid. It is a 20-carbon fatty acid with three double bonds named
after James Mead, a lipids researcher at the University of California
at Los Angeles who first identified it. An elevated level of Mead acid
in the body is a marker of EFA deficiency.
According to Peat, elevated levels of Mead acid constitute proof that
your body can make EFAs. However, the Mead acid acts as a "filler"
fatty acid that cannot serve the functions that the original EFA are
needed for. Peat claims that Mead acid has a full spectrum of protective
anti-inflammatory effects; however, the body cannot convert Mead acid
into the elongated fatty acids that the body needs for making the various
anti-inflammatory prostaglandins.
Peat also asserts that polyunsaturated fatty acids become rancid in
our bodies. This is not true; the polyunsaturated fatty acids in our
cell membranes go through different stages of controlled oxidation.
To say that these fatty acids become "rancid" is misleading.
Of course, EFAs can become rancid through high temperature processing
and it is not healthy to consume these types of fats. But the EFAs that
we take in through fresh, unprocessed food are not rancid and do not
become rancid in the body. In small amounts, they are essential for
good health. In large amounts, they can pose health problems which is
why we need to avoid all the commercial vegetable oils containing high
levels of polyunsaturates.
Peat’s reasoning has led him to claim that cod liver oil causes
cancer because cod liver oil contains polyunsaturated fatty acids. Actually,
the main fatty acid in cod liver oil is a monounsaturated fatty acid.
The two main polyunsaturated fatty acids in cod liver oil are the elongated
omega-3 fatty acids called EPA and DHA, which play many vital roles
in the body and actually can help protect against cancer. Furthermore,
cod liver oil is our best dietary source of vitamins A and D, which
also protect us against cancer.
Actually, Peat’s argument that polyunsaturated fatty acids become
harmful in the body and hence cause cancer simply does not make sense.
It is impossible to avoid polyunsaturated fatty acids because they are
in all foods.
EFAs are, however, harmful in large amounts and the many research papers
cited by Peat showing immune problems, increased cancer and premature
aging from feeding of polyunsaturates simply corroborate this fact.
But Peat has taken studies indicating that large amounts of EFAs are
bad for us (a now well-established fact) and used them to argue that
we don’t need any at all.
Finally, it should be stressed that certain components of the diet
actually reduce (but do not eliminate) our requirements for EFAs. The
main one is saturated fatty acids which help us conserve EFAs and put
them in the tissues where they belong. Some studies indicate that vitamin
B6 can ameliorate the problems caused by EFA deficiency, possibly by
helping us use them more efficiently.
About the Author
 Mary
G. Enig, PhD is an expert of international renown in the field of lipid
biochemistry. She has headed a number of studies on the content and effects of
trans fatty acids in America and Israel, and has successfully challenged
government assertions that dietary animal fat causes cancer and heart disease.
Recent scientific and media attention on the possible adverse health effects of
trans fatty acids has brought increased attention to her work. She is
a licensed nutritionist, certified by the Certification Board for Nutrition Specialists,
a qualified expert witness, nutrition consultant to individuals, industry and
state and federal governments, contributing editor to a number of scientific publications,
Fellow of the American College of Nutrition and President of the Maryland Nutritionists
Association. She is the author of over 60 technical papers and presentations,
as well as a popular lecturer. Dr. Enig is currently working on the exploratory
development of an adjunct therapy for AIDS using complete medium chain saturated
fatty acids from whole foods. She is Vice-President of the Weston A Price Foundation
and Scientific Editor of Wise Traditions as well as the author of Know
Your Fats: The Complete Primer for Understanding the Nutrition of Fats, Oils,
and Cholesterol, Bethesda Press, May 2000. She is the mother of three healthy
children brought up on whole foods including butter, cream, eggs and meat.
IMPORTANT CORRECTION
In the Winter 2004 "Know Your Fats" column we stated that
Siberian pinenut oil was a good source of gamma-linolenic acid (GLA).
This was indicated from fatty acid analyses performed in Siberia. We
have since performed further tests on the oil and found that it does
not contain significant amounts of GLA but rather a fatty acid called
pinoleic acid, an 18-carbon fatty acid with three double bonds but with
the first double bond on the fifth carbon, not the sixth, as in GLA.
We are sorry for any inconvenience this may have caused.
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