Hydrogenation was originally developed to produce low-cost soap. It's the process of
modifying fat artificially converting liquid fats into solids as in margarine, lard,
non-dairy cream, bakery products, and nut butters. One reason manufacturers prefer the use
of hydrogenated oils is because they extend shelf life (life of the food, not yours!). And
don't be fooled by the label reading "made from partially-hydrogenated fat"
partially-hydrogenated fat is worst then totally hydrogenated fat.
The higher levels of harmful fats are at the expense of essential fatty acids. The term
"essential" in nutrition jargon means your body can't make it, so it must be on
your plate! Since it has become virtually impossible to avoid a consistent, daily dietary
intake of trans-fatty acids, Medical Hypotheses advises that "a precautionary,
preventative supplementation of the diet with supplements containing essential fatty acids
would be prudent. Such supplements are readily available. Look for flax seed and fish oils
at your health store."
1.Journal of the American College of Nutrition, 1993 Dec, 12:651.
2.Medical Hypotheses, 1992 Apr, 3 7:24 1.
Health Risks from Processed Foods
and The Dangers of Trans Fats
Dr. Mary Enig Interviewed By Richard A. Passwater,
Mary G. Enig, Ph.D., a nutritionist widely known for
her research on the nutritional aspects of fats and oils, is a consultant,
clinician, and the Director of the Nutritional Sciences Division of Enig
Associates, Inc., Silver Spring, Maryland. She received her PhD in Nutritional
Sciences from the University of Maryland, College Park in 1984, taught a
graduate course in nutrient-drug interactions for the University's Graduate
Program in Nutritional Sciences, and held a Faculty Research Associateship
from 1984 through 1991 with the Lipids Research Group in the Department of
Chemistry and Biochemistry. Dr. Enig is a Fellow of the American College of
Nutrition, and a member of the American Institute of Nutrition. Her many years
of experience as a "bench chemist" in the analysis of food fats and
oils, provides a foundation for her active roles in food labeling and
composition issues at the federal and state levels.
Dr. Enig is a Consulting Editor to the "Journal
of the American College of Nutrition" and formerly served as a
Contributing Editor to "Clinical Nutrition." She has published 14
scientific papers on the subject of food fats and oils, several chapters on
nutrition for books, and presented over 35 scientific papers on food and
nutrition topics. She is the President of the Maryland Nutritionists
Association, past President of the Coalition of Nutritionists of Maryland and
was appointed by the Governor in 1986 to the Maryland State Advisory Council
on Nutrition and served as the Chairman of the Health Subcommittee until the
Council was disbanded in 1988.
I first learned of Dr. Mary Enig's research from a
1978 report in the Federation Proceedings. We met shortly after that, and
since I had written about trans fats several times in Supernutrition, we had
common concerns about the effect that these trans fats from processed foods
were having. We were both concerned particularly about the misconception that
processed margarine was better than natural butter.
In several visits by Dr. Mary Enig to the Solgar
Nutritional Research Center I quickly learned that she was an exacting
scientist who is not afraid to speak out and who supports good nutrition, not
just going along with the establishment's party line. While studying for her
Ph.D. at the University of Maryland, often she would first respond with the
"correct" answer that was expected, and then she would explain why
new research indicated "alternatives," such as optimal vitamin and
mineral nourishment, provided a better answer. It is not easy be credentialed
by the "system," while your own research shows other facts.
In her 1978 report, Dr. Enig challenged the
speculation concerning the relationship of dietary fat and cancer causation.
She concluded that correlations between the increase in per capita dietary fat
intake and total cancer mortality over a sixty-year period show significant
positive correlations for total fat and vegetable fat, and negative
correlation for animal fat. That is the cancer rate is higher when the amount
of vegetable fat or total fat is higher in the diet, but the cancer rate is
lower when there there is more animal fat in the diet. These findings were
unpopular then as they are today, but they are still correct. It is convenient
to blame everything on red meat and animal fat, and believe that vegetable oil
is the great dietary salvation-even if it is partially hydrogenated. At least
that is what the vegetable oil people would like everyone to believe.
Now, we are not saying that lots of dietary fat is
good for you and that vegetables are not good. Eating vegetables, fruits and
other whole foods is very desirable. However, that is not the same as eating
partially-hydrogenated vegetable oils. Americans eat too much fat (especially
partially hydrogenated vegetable oils) and not enough fruits and vegetables.
The problem is that the typical American is not eating enough whole foods, but
instead, is eating too much partially-hydrogenated vegetable oil-a
fractionated food-that has been made into "funny foods" such as
margarine or added to baked goods. Such "funny foods" are far
differentthan real whole foods.
Hydrogenation ruins the nutritional value of vegetable
oils! Why would anyone want to ruin the nutrition value of vegetable oils? The
purpose of hydrogenation is to solidify an oil so that it can be made to
resemble real foods such as butter. The hydrogenation process imparts
desirable features such as spreadability, texture, "mouth feel," and
increased shelf life to naturally liquid vegetable oils. In the hydrogenation
process, vegetable oil is reacted under pressure with hydrogen gas at 250 -
400oF for several hours in the presence of a catalyst such as nickel or
platinum. However, this industrial process cannot control where the hydrogen
atoms are added to the "unsaturated" double bonds. Randomly adding
hydrogen atoms to polyunsaturated fats converts natural food components into
many compounds, some of which have never seen before by man until partially
hydrogenated fats were manufactured.
Some of the several dozens of altered compounds
created in the manufacture of partially-hydrogenated fats are
"trans" fatty acids. Fatty acids are the building blocks of fats,
much like amino acids are the building blocks of proteins. Other new compounds
accidentally synthesized include fatty acids having double bonds translocated
to new and un-natural positions, and various molecular fragments. Many of
these altered compounds are detrimental to health.
Since "trans" fats are so detrimental to our
health. permit me to briefly review the relevance of distinguishing between
"trans" and "cis" fats before chatting with Dr. Enig.
Recently, in the September issue, in the interview with Dr. Jim Clark and Mr.
Lance Schilipalius, we discussed "trans" isomers of carotenoids.
"Trans" means the same thing here. "Cis" and
"trans" isomers refer to how identical atoms are added to double
bonds. When the atoms are added to the same side of the double bond, the
compound is called "cis" and the molecule is bent because of the
crowding of the atoms on one side. When the atoms are added on opposite sides
of the double bond, the compound is called "trans" and molecule is
"space-balanced" and straightened. The shape of a molecule is
important because enzymes and their substrates-the molecules enzymes act
upon-must fit together like a key in a lock.
Dr. Enig will discuss this during the interview, but
the important thing to remember is that natural polyunsaturated fatty acids
are "cis" compounds and are bent. Partial hydrogenation produces
many un-natural "trans" fats which are straight and not intended for
use in the human body. You don't have to understand the difference between
"trans" and "cis," but it is important that you know that
there is a difference because, as Dr. Enig will explain, it can affect your
Passwater: Dr. Enig, a lot of people are
interested in "trans" fats now. You have been researching them since
1977. How are trans fats harmful to us?
Enig: More than a decade of research at the
University of Maryland, as well as research that was being done at other
institutions, showed that consumption of trans fatty acids from partially
hydrogenated (a process that adds hydrogen to solidify or harden) vegetable
fats and oils had many adverse effects in health areas such as heart disease,
cancer, diabetes, immunity, reproduction and lactation, and obesity. It is
rather easy today to come up with a long list of these adverse effects from
the published research done by many scientists around the world, as well as
the researchers at the University of Maryland.
The reason there is so much recent interest is that
during the past three years there has been a number of major research reports
published in prestigious medical journals that caught the attention of the
press. These and earlier reports had shown, for example, that consumption of
trans fatty acids lower the "good" HDL cholesterol in a dose
response manner (the higher the trans fat level in the diet, the lower the HDL
level in the blood) and raise the atherogenic lipoprotein(a) in humans as well
as raising the "bad" LDL cholesterol and total blood cholesterol
levels by 20-30 milligram-percent. These studies have usually been shown in
independent non-industry studies. Perhaps the most significant event though
was the report from researchers at Harvard University, who evaluated more than
85,000 women in a long-term prospective study and found that there was a
significantly higher intake of trans fatty acids in those individuals who
developed heart disease.
As regards to the question of cancer, trans fatty
acids induce adverse alterations in the activities of the important enzyme
system that metabolizes chemical carcinogens and drugs (medications), i. e.,
the mixed-function oxidase cytochromes P-448/450. The initial research in this
area was done by the Maryland group in collaboration with the U. S. Food and
Drug Administration, and was followed by the more extensive evaluation that I
did for my Ph.D. dissertation; several groups around the country and the world
also reported the same or similar results. Several groups around the world
reported a higher intake of partially hydrogenated fats in those individuals
who have developed cancer.
Both primate and human studies have shown
inappropriate handling of blood sugar; trans fatty acids decrease the response
of the red blood cell to insulin, thus having a potentially undesirable effect
in diabetics. The primate research was initiated at Maryland in collaboration
with the U. S. Department of Agriculture and the National Institutes of
Health, and the human research is from the University of Pittsburgh and quite
One major concern is that trans fatty acids adversely
affect immune response by lowering efficiency of B cell response and
increasing proliferation of T cells. This was shown in research done at
Maryland using a mouse model and although there are reports from clinicians
that there are problems of immune dysfunction in humans it still needs to be
evaluated systematically in humans.
Recent research from outside the U. S. has indicated
that trans fatty acids interfere with reproductive attributes and of concern
is the finding that trans fatty acids lower the amount of cream (volume) in
milk from lactating females in all species studies including humans, thus
lowering the overall quality available to the infant. The latter research was
done at Maryland by my colleague Dr. Beverly Teter.
Basically, trans fatty acids cause alterations to
numerous physiological functions of biological membranes that are known to be
critical for cell homeostasis, e.g., appropriate membrane transport and
membrane fluidity, and these fatty acid isomers produce alterations in adipose
cell size, cell number, lipid class and fatty acid composition.
Passwater: Now that trans fats are becoming of more
interest, the term may still just be a buzz word to many of our readers. Would
you explain just what are trans fats? Where do they come from? How are they
Enig: To understand what trans fatty acids are
you have to understand what fatty acids are. Fatty acids are basically chains
of carbon with a carboxyl group (COOH) at one end that can react (e.g.,
combine) with another molecule. When fatty acids are in fats or oils they are
combined with glycerol in the proportions of three fatty acid molecules to one
glycerol molecule and they form triacylglycerols or in common terminology,
Fatty acids come in different chain lengths ranging
from three carbons long (propionic acid) to 24 carbons long (lignoceric acid).
These fatty acids are either "saturated" (with an adequate number of
hydrogen atoms) and chemically stable, or they are "unsaturated"
(missing adequate hydrogens) and chemically unstable. If a fatty acid is
missing two hydrogens, it is called a monounsaturated fatty acid, and in place
of the two hydrogens, the adjacent carbons "double" bond to each
other. If the fatty acid is missing four or six or more hydrogens, it is
called a polyunsaturated fatty acid, and it is even more unstable than the
monounsaturated fatty acid. Because the double bonds in naturally occurring
plant oil fatty acids are curved with a "cis" configuration, the
fatty acids cannot pack into a crystal form at normal temperatures so their
presence produces a liquid oil. Saturated fatty acids have a straight
configuration and can pack into a solid crystal at normal temperatures.
If the unsaturated fatty acids are altered by partial
hydrogenation to straighten the chains so that they have some of the physical
packing properties of saturated fatty acids they have had their
"cis" double bond changed to a "trans" double bond and
they turn a technically mostly unsaturated oil into a solid fat. The trans
fatty acids are the same length and weight as the original "cis"
fatty acid they were formed from, and although they have the same number of
carbons, hydrogens, and oxygens they are shaped differently in space. The term
that is used is that they are "isomers." The problem arises when a
large number of the trans fatty acids are consumed from foods and they are
deposited in those parts of the cell membranes that are supposed to have
either saturated fatty acids or "cis" unsaturated fatty acids; under
these circumstances the trans fatty acids essentially foul up the
Although the trans fatty acids are chemically
"monounsaturated" or "polyunsaturated" they are considered
so different from the "cis" monounsaturated or polyunsaturated fatty
acids that they cannot be legally designated, e.g., monounsaturated for
purposes of labeling. Most of the trans fatty acids produced by the partial
hydrogenation process are chemically monounsaturates.
There have always been small amounts of one kind of
trans fatty acids in the human diet from the ruminant fats (dairy, sheep,
goat, deer, buffalo, antelope, etc.) because the microorganisms in the rumen
try to get rid of the polyunsaturated fatty acids that are found in the plant
foods eaten by these animals. In the early days of trans fatty acid research,
the researchers assumed that the trans fatty acids found in ruminant fats were
no different than those produced by partial hydrogenation in the factory. But
the studies showed that not only was the amount much smaller (e.g., the fat in
butter might be 2-3% of the ruminant trans), the effect on the
"machinery" in the cell membranes was not different than without the
trans. Yet all studies feeding the trans produced by partially hydrogenating
the vegetable oils showed the adverse effect on the cell
Passwater: Why are trans fats a problem?
Enig: The various mechanisms through which the
trans fatty acids disrupt function are related in part to the ability of trans
fatty acids to inhibit the function of membrane related enzymes such as the
delta-6 desaturase resulting in decreased conversion of e.g., linoleic acid to
gamma-linolenic acid or arachidonic acid; interference with the necessary
conversion of omega-3 fatty acids to their elongated tissue omega-3 fatty
acids; and escalation of the adverse effects of essential fatty acid
deficiency. This latter effect was shown especially by the work of Dr. Holman
and his colleagues at the Hormel Institute at the University of Minnesota, the
other effects have been shown by many researchers including the University of
Passwater: What were your early findings and what got
you interested in this area of research?
Enig: My initial published research in 1978
when I was at the University of Maryland showed that trans fatty acids, which
were increasing in the food supply at the time and which had not been
catalogued in any of the food data tables, were the very factors that
explained the positive statistical relationship between the increase in cancer
mortality and vegetable fat consumption in the U. S.
It was clear from the literature that once the trans
fatty acids were identified as products of partial hydrogenation and studies
were engaged in, there were a number of earlier researchers who questioned the
biological safety of the trans fatty acids viz a viz their relationship to
both cancer and heart disease. In fact, Dr. Ancel Keys had originally claimed
that the partially hydrogenated vegetable oils with their trans fatty acids
were the culprits in heart disease. This was in 1958, and the edible oils
industry was very swift in their squelching of that information; they shifted
the emphasis to "saturated" fat and started the phoney attack on
meat and dairy fats.
Passwater: What have others added to your
Enig: As you have noted in some of your
writings, we at the University of Maryland were not the first to raise the
issue of trans fatty acids and adverse health effects; Dr. Fred Kummerow from
the University of Illinois, Dr. George Mann from Vanderbilt University, and
Dr. Edward Pinckney with the American Medical Association had sounded the
alarm many years before my plunge into the foray. In fact, I had drawn heavily
on the research findings of Dr. Kummerow and the informative writing of Dr.
Mann when I first started to investigate what was known about health effects
of trans fatty acids at the time. Our research findings have been duplicated
by others, but more importantly other independent researchers have extended
and explained many of our findings and concerns.
How You Can Help Support The Web Site Development
One of the ways that you can help support the web site
is that you can now purchase books through Amazon.com by clicking through on
my web site. I obtain a tiny percentage of the sale and that will help support
my ability to provide high quality content at no charge to you. However this
will only work if you click on
Dr. Enig's Book or the Amazon icon below. It does not work if you go
directly to Amazon. I am only recommending books that I would purchase for my
own home library, which this book is already a part of. I plan on offering a
complete review of this book in the future. A brief review is that it seems to
be the best book on the market to explain the details of fat metabolism. She
is the author of the incredible article
on soy that I published earlier.
STUDIES SHOWING THE DANGERS OF TRANS-FATTY ACIDS
The safety of high dietary trans-fat intake during pregnancy and even before pregnancy
is especially questionable. Mothers-to-be, please check food labels carefully.
Source: Acta Paediatrica, 1992 Apr, 81:302.
Dietary trans-fatty acids raise LDL cholesterol and result in reductions of HDL
Source: American Journal of Clinical Nutrition, 1994 Apr, 59:861.
Hydrogenated fats increase the risk of coronary heart disease.
Source: Science, 1994 Apr 22, 264:5 3 2.
Trans-fatty acids may increase cholesterol levels. Total fat intake, independent of
fatty acid type, is not strongly associated with coronary heart disease. (In other words,
the type of fat, not the total fat, is the significant factor.)
Source: Medical Journal of Australia, 1992 May 4, 156 Suppl:S9-16.
Intake of margarine - the major source of trans-fatty acids - is significantly
associated with risk of heart disease.
Source: Circulation, 1994 Jan, 89:94 0
The main sources of trans-fatty acids are partially-hydrogenated vegetable fats and
Source: Zeitschrift fur Ernahrungswissenschaft, 1992 Sep, 31:196.
Healing fats are required, together with other nutrients,
to prevent and reverse so-called "incurable" degenerative diseases: heart
disease, cancer, and Type II diabetes.
Healing fats also help reverse arthritis, obesity, PMS,
allergies, asthma, skin conditions, fatigue, yeast and fungal infections, addictions,
certain types of mental illness, and many other conditions.