Health Risks from Processed Foods and Trans Fats: An interview with Mary Enig, Ph.D.

PART II Trans fats from partially-hydrogenated oils are the real culprits for which saturated fats have been blamed.

by Richard A. Passwater, Ph.D.

Dr. Mary G. Enig, 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.

Last month we talked mostly about what trans fats (TFAs) were, how they interfere with "machinery" of our normal cell biology and that they are a recent and unnatural intrusion into our diets. In Part II, we will look into the health problems caused by TFAs, and in Part III, Dr. Enig will put the research on TFAs and other fats in perspective and give us her thoughts on the pluses and negatives of the Health Food Industry as seen from academia.

Passwater: You mentioned the your research was stimulated by the early investigations of Drs. Fred Kummerow, George Mann and Edward Pinckney. What did you set out to investigate and what have others added to these findings?

Enig: Much of the Trans-Fatty Acid (TFA) research that was accomplished at the University of Maryland from 1977 to today was done to answer some very basic questions. For example, we wanted to know how much TFAs people were being exposed to. So during some of the early research, we measured the amounts of TFAs in typical U. S. foods and then estimated the amounts in various diets and in the food supply.

The next set of efforts was done to measure the effects that feeding diets containing physiologically relevant amounts of TFAs to laboratory animals had on some reproductive and lactation functions, on the alteration of membrane properties, and on the consequent alteration of enzyme functions that had physiological importance. These different efforts were measured by our research group, and many of our findings, e. g., that the enzyme functions were adversely affected, were repeated by various other research groups. It is hard to tell sometimes if we were repeating the findings of others or if others were repeating our findings. I think it is safe to say that the research was invariably reproducible as long as the same animal model and the same amount of TFAs were used. In other words, our findings were real and other researchers could easily find the same thing.

A number of research groups were able to use some of our basic findings, and many of the researchers were using their own models and their research was providing information that was parallel and complementary to ours. In many instances, the other research teams had access to better funding and models that we did not have at the University of Maryland.

One research group at Auburn University examined diets of adolescent girls and directly measured the TFAs in their diets by laboratory analytical methods. [16, 17] They found that approximately two-thirds of the TFAs in the diets of these adolescents could be predicted by the food composition data in our 1983 research paper for 220 foods. This is rather remarkable since their research was done in another part of the country. It does show the similarity of many of the same types of partially hydrogenated fats in diets across the US.

A research group at Louisiana State University studied, among other things, the effects of TFAs on what is called "the second messenger," cyclic AMP and the digitalis receptor. [18] They found that TFAs affected both.

Still another research group, this one at Virginia Polytechnic Institute, studied the effect of TFAs on bone development. [19, 20] Their research showed some very undesirable effects! AS far as I know, the latter two groups who were finding important effects have not been able to continue because of lack of funds for TFA research. Their efforts were done independent of our concerns and findings but parallel to our efforts.

There have been a number of other research efforts that have been given widespread publicity. These include the published findings from Dr. Martijn Katan's lab in Holland that the TFAs lower the "good" High-Density Lipoprotein (HDL) and raise the "bad" lipoprotein [a] (Lpa) which is atherogenic. [21] Also, the published findings from Dr. Walter Willett's research at Harvard on 85,000 nurses, as well as other prospective studies, have showed that those people who consumed the most TFAs had the most heart disease. [3] Dr. Willett's group also has preliminary, as yet unpublished, data that those individuals who developed breast and prostate cancer had higher intakes of TFAs. These findings have been presented at scientific meetings by Dr. Willett and his staff.

I have recently prepared a technical report which includes additional information that would normally not be found in typical scientific reviews. [22] This information is of special interest to many in the food industry and the regulatory agencies. The report identifies all of the different research groups that have been working on TFAs around the world over the past 60 years.

Passwater: I remember how the processed food industry tried to suppress your early research. As Rodney Leonard, the editor of Nutrition Week noted, you fought tenaciously to bring out the truth and were "a burr under the saddle of the [processed food] industry and the government, persistently challenging the contention that the health threat of trans fatty acids is overplayed and that the current level of consumption poses no threat to public health." Most of those who were skeptical then have examined the steady stream of new data and now agree with you that TFAs are a major health threat. How were you able to keep on? What techniques were used against you and how did you overcome them? Where did you find moral and scientific support?

Enig: As you know from some of our past conversations, we ran into some strong challenges from certain segments of the edible oil industry regarding our findings. In addition to writing several articles to "refute" our findings, and seeing to it that our major reports did not get properly referenced, those individuals who actively opposed our research were able to influence funding sources. Gradually though, other researchers started to realize that we were correct and appropriately conservative in our approach to research, and consequently, most of the "bad-mouthing" that we encountered has backfired.

Passwater: Yes, I remember well how we were both encountering difficulties with "the establishment." I am happy to note, as you well know, that the same is happening regarding my findings regarding vitamin E and the prevention of heart disease, and of the antioxidant nutrients in the prevention of cancer. We never did get the funding needed to further pursue our research.

Enig: You're right. At the University of Maryland we never did get the type of funding that you need to receive to continue the level of research that would have been desirable, but what funding we did receive was carefully managed and many of the people in our research group were dedicated to the research.

I think we found moral support because we knew we were scientifically correct, and ultimately the scientific support came as other researchers started to evaluate the problems without having certain industry people set up their research protocol. AS you realize from your years of involvement in research, good research properly done is always reproducible, if all the variables are the same, but it is also possible for unscrupulous individuals to set up a research protocol designed to obfuscate, and if that gets published, it keeps other good researchers from continuing to work in the area. Frequently, those individuals who are coopted write their summary and abstract the way the industry wants them to, but they usually leave their data intact so that a knowledgeable researcher can recognize the inconsistency. However, it is a very time- consuming task to constantly challenge each piece of misinformation that you see.

Passwater: Yes, it is a difficult task, but you and I give it our best shots. In the past we did a lot of challenging others to prove us wrong, and now we can smile a lot.

Enig: Our work is not done yet! There is still much to do.

Passwater: Right again! How big is the problem with TFAs? How extensive are trans fats in our modern diets, and how does this compare to ancient diets and other diets around the world.

Enig: Today the levels of TFAs vary around the world from practically zero to levels much like those found in our foods in the U. S. It depends on how much partially hydrogenated vegetable fats or partially hydrogenated marine oils are present in the food supply.

Without the commercial partial hydrogenation process, as would have been the case more than a hundred years ago, the levels of TFAs in diets would be relatively low. Only the ruminant fats would have supplied any, and the types of isomers that are found in the ruminant fats behave in a very different way from those found in the partially hydrogenated vegetable oils. Additionally, the research shows that the TFAs are more of a problem when the level of saturated fat is low. Diets that are higher in ruminant fats are also higher in saturated fats. Most ruminant fats have about 2-3% TFAs whereas the partially hydrogenated vegetable fats are commonly 30-40% and as high as 53% in foods in this country.

After analyzing hundreds of food samples for TFAs, chemically analyzing food composites, and calculating dietary information, I am confident that there are many people in this country who consume 20% of the total fat in their diet as TFAs. On average though, 10.9% is the number we came up with when we looked at all of the published analyses. The typical french fried potatoes are around 40% TFAs, and many popular cookies and crackers range from 30 to 50% TFAs, and every donut I have analyzed has about 35 to 40% TFAs. Since these are all fairly high fat products, someone who eats a lot of these types of foods will get a large amount of TFAs. Several years ago, we documented nearly 60 grams of TFAs in someone's typical daily diet.

Passwater: Wow! I hope that's no one I know. Dr. Enig, you mentioned that TFAs are atherogenic -- that is they cause atherosclerosis. Then you mention that TFAs are more of a problem when saturated fats are low. Yet most people fear saturated fats because they have been told that it is the saturated fats that cause heart disease.

You are recognized as a leading expert on fats and oils, do saturated fats cause heart disease?

Enig: The idea that saturated fats cause heart disease is completely wrong, but the statement has been "published" so many times over the last three or more decades that it is very difficult to convince people otherwise unless they are willing to take the time to read and learn what all the economic and political factors were that produced the anti-saturated fat agenda.

Periodically, various reports have come out that show the inconsistencies in the theory. You have already discussed this with the well-known cholesterol and lipids researcher, Dr. David Kritchevsky of the Wistar Institute. [23] In 1977, Dr. Kritchevsky noted that it did not make any difference what kind of fat was added to the whole foods diets in animal studies -- only when the diets were very unnatural chemically could changes be brought about -- and from study to study these changes were inconsistent. [24]

As you frequently report, the latest theories regarding heart disease point to oxidized fats and oxidized lipoproteins as culprits. This being the case, accusations against chemically- stable, basically non-oxidizable saturated fat don't make sense. Most people who find fault with saturated fats do not really understand that our cells are busy making saturated fatty acids all the time from carbohydrates and excess protein.

Passwater: Do tropical oils cause heart disease?

Enig: No they don't. Several studies have shown that there is no increase in heart disease in countries or communities where most of the fat is either coconut oil or palm oil. Palm oil that is not extensively refined has very high levels of antioxidants, and coconut oil has high levels of very useful medium chain fatty acids. There are many older research studies that showed that adding quite a bit of coconut oil to the diet of persons having high blood cholesterol reduced their level of cholesterol. Dr. George Blackburn from Harvard Medical School has written an extensive review on this topic. [25]

It is unfortunate that this misinformation about these oils became so widespread because they are very stable oils that have unique functional properties and products made with them as the fat component usually have far less fat and therefore fewer calories. Needless to say, they would also have virtually no TFAs which are unquestionably atherogenic. When coconut oil was used in the manufacture of crackers, very little fat was added to each cracker, but the crackers did not become stale before they could be purchased. Now the fat-free crackers become very stale very quickly, and the crackers made with the more unsaturated oils are higher in fat and are greasy or they appear drier because they are made with the high-temperature melting partially hydrogenated oils. Deep fried foods made in these oils never absorb quite as much fat as they do when they are fried with the more unsaturated oils.

Passwater: Speaking of deep fried french fries, I notice that the Community Nutrition Institute is pleading with McDonald's to go back to their old cooking oil, an animal tallow. CNI cited higher risks of coronary heart disease, coronary artery disease, and low birth-weight babies due to the partially hydrogenated vegetable oil that McDonald's has been using since 1990. [26]

Enig: Yes, when I analyzed the oils, I found that the percentage of fat that was saturated fat in their french fries dropped from 49% to 24% when McDonald's switched from animal tallow to partially hydrogenated vegetable oil. But the percentage of fat that was TFAs rose from 5% to 42-48%. McDonald's own study showed that the total amount of fat in its fries rose from 17.6% to 27.9% Recently, McDonald's has again switched to an oil that has cut the TFAs in half. But, those who insist on eating french fries were better off when the beef tallow was used.

Passwater: Why were earlier researchers misled about saturated fats and heart disease?

Enig: The simplistic, abbreviated story of how some of the anti- saturated fat rhetoric got started and then took a strangle hold, is that when laboratory animals were fed semi-purified and artificially saturated (fat) diets, the animals actually became deficient in essential fatty acids. As a result, these animals developed lesions that were incorrectly defined as the equivalent of heart disease. This "research" was touted as showing an effect of "saturated" fat. Then when Dr. Ancel Keys of the University of Minnesota reported that hydrogenated fats were responsible for heart disease [15], the response from the threatened edible oil industry was to claim that it was only the saturated fats that were the culprits, and that the industry would get rid of the problem by only partially hydrogenating the oils. From that point on, the saturated fats stood "guilty as accused," even though study after study showed that there was no relationship between saturated fat intake and the development of heart disease.

In fact, some of the studies showed that there was less progression of the disease process when the saturated component was higher. [27] Usually the proponents of the lipid hypothesis managed to squelch the effect of these reports. Of course the partially hydrogenated oils were really very little different in saturated fat level than the fats and oils that had been called "hydrogenated," but the public and the media and many of the naive researchers didn't know that.

As time went on, the whole heart disease agenda became a multi-million dollar business that was benefiting the researchers funded by the part of the National Institutes of Health that deals with heart disease, the National Heart, Lung and Blood Institute. The only people not benefiting were and are the consumers who are continuing to get more and more heart disease at higher and higher costs. The consumer may not be dying from heart disease as often as they were 30 years ago, but they are undergoing more surgery such as by-pass and angioplasty, and they are swallowing more expensive cholesterol-lowering drugs. All in all, while the so-called mortality figures have decreased, the incidence has greatly increased.

Of course, the ill-trained consumer activist groups have added to the problem by continuing to publish their own misinterpretations of the science, and this in turn, is further publicized in the media.

Passwater: Well, I see that you haven't backed off and cow-towed to the consensus pseudo-scientists that form opinions without looking closely at the data. I would like you to explain the real facts and their proper interpretation for the benefit of our readers. So let's look at fats and cholesterol, TFAs and the obesity trigger, and your thoughts on helping the Health Food Industry in Part III.

All rights, including electronic and print media, to this article are copyrighted to Richard A. Passwater, Ph.D. and Whole Foods magazine (WFC Inc.).