Fwd: The Dangers of Trans Fats 6-10-00

[Guest guest]

CancerAnswer, " mrsjoguest " <joguest@m...> wrote:

CancerAnswer, JoAnn Guest <joguest@m...> wrote:

 

-->Health Risks from

> Processed Foods and The Dangers of Trans Fats <!--

 

>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 different than 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

> health.

 

> 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 recent.

 

 

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 formed?

 

 

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,

> triglycerides.

 

>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 " machinery.

 

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

> " machinery. "

 

Why are transfats 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 Maryland

> researchers.

 

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 findings?

 

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.

--- End forwarded message ---