contributed by John Macdonald
Cuordha Goldens
Nova Scotia, Canada
cuordha@chebucto.ns.ca

Here is a series of four articles I put together on the subject of ethoxyquin. The second article titled ETHOXYQUIN - AGAIN was the original article I had referred to. When going through my files I came across the other three articles and decided to include them as well.

Note from John Macdonald - June 6, 1996
This article was written 5 years ago and many manufacturers have changed their formulations of their products so any data quoted in the article is probably not accurate today. There is more research going on about ethoxyquin but I have not seen any results so do not plan to update this article.

ETHOXYQUIN - FRIEND OR FOE by John Macdonald

In the US there has recently been a controversy brewing over the use of ethoxyquin as a preservative in pet foods. This is an ingredient which used as a fat stabilizer and preservative and is found primarily in the premium pet foods which have high fat levels although there are other pet foods which contain it as well. There appears to be two sources from whence the controversy arose. One is a pet owner who lost 3 10 year old dogs to cancer in a very short time period. Another is an article written by Elaine Campbell, a Collie breeder, in New England Obedience News in which she details coat and pigmentation problems which cleared up after switching foods (the problem with the original food appeared to be a zinc deficiency). On this new food the dogs did well but soon bitches began skipping heats, a blue merle stud suffered an immune breakdown, and bitches that did get bred began having puppies with missing parts.

Now what is ethoxyquin? It is an antioxidant which is FDA approved and has been in animal feeds for over 30 years. It is used to prevent oxidization and rancidity in fats in order to maintain wholesomeness and quality in pet food. It significantly reduces the levels of BHA and BHT (which are also antioxidants) required for preservation. In an article printed in the Cornell University College of Veterinary Medicine Animal Health Newsletter, Vol 6, No. 9, Nov.,1988 it is stated that they are not aware of any evidence that ethoxyquin, at the levels used in pet foods, acts as a carcinogen. " It should be noted that many substances in the diet are beneficial at low levels but harmful when present in excess. This is as true for essential nutrients like Vitamins A and D and iodine as it is for chemical additives. No nutritionist would recommend completely eliminating vitamin A from the diet just because high levels are toxic. The same can be said for preservatives like ethoxyquin. When used in small amounts to prevent rancidity, they are valuable and important components of the diet."

What else is it used for? Besides being an anti-oxidant ethoxyquin is also used as an herbicide, a spray for apple scale and a rubber stabilizer. It has been stated that it has never been approved for human consumption. In actual fact this is not true. The FDA has approved it for use as a food additive for use in the production of paprika, chili powder and ground chili. It has also been used as an antioxidant for apples and pears. According to Monsanto, a principal manufacturer of ethoxyquin, "Studies have shown that ethoxyquin scavenges the harmful products of oxidation and, in so doing maintains cellular integrity, which reduces the risk of cancer."

There have been studies which have shown no link between ethoxyquin and cancer. All well and good but do we wish to introduce yet another chemical into our pet's diet? Use of ethoxyquin reduces the amount of BHA and BHT used so is this good or bad? How many of you can remember the fuss that was made 30 years ago when BHA and BHT came into wide use? It was stated then that they were potentially harmful to people. Yet today they are fully accepted. Can we trust the FDA and research work being done? Are the horror stories of cancer and immune problems, etc. truly the result of a single additive or is the picture much broader than this? What is the impact of our chemical laden environment in general on both our health and the health of our pets? What impact does swimming in a lake polluted by acid rain have? The point that I am trying to make is that it is easy to try and blame a single thing when indeed the picture is much more complex than this. Do not jump on the latest bandwagon, be it on nutrition, training methods, or whatever. Study the facts, collect hard data, not rumors (e.g. I heard that ...) and then form your own opinion.

ETHOXYQUIN - AGAIN

Ethoxyquin - a word which strikes fear into the hearts of brave men and sends little children to hide under their beds - or is it? Is it the cause of all the problems that have been attributed to it or not? Are we becoming caught up in what appears to be a mass hysteria on the topic?

Now that I have your attention let's sit down and look at this topic in a practical light. My main concern is that I don't want to see anybody have a knee jerk reaction to anything. There has been a lack of research that to me is evident in some of the statements made about ethoxyquin. First it was claimed that ethoxyquin was the only common factor found among breeders who are having various problems. No mention was made whether other factors such as environment, location in relation to industrial areas, pollution, breeding programs, histories of genetic predispositions of certain breeds to specific problems, etc. etc. Second a number of manufacturers have stated that their products are preserved naturally and do not contain ethoxyquin. Recently it has been determined that this is not necessarily true. What these manufacturers are saying is that they do not add it. This means that the fats they buy to put in their foods has had it added in order to stabilize the fat and prevent rancidity which will certainly cause health problems, if not death. As a concrete example, IAMS has been mentioned frequently along with Science Diet and Purina as containing ethoxyquin. Allowable levels are 150 ppm in animal feeds and is a level found in many products, IAMS is 85 ppm and Natural Life, which is advertised as preserved naturally, contains a concentration of 25 ppm. The best way to find out what a product contains is to have a competitor analyze it.

Who do we believe?

Everybody is out to protect their own interests. Information published by dog food manufacturers is geared to selling their own product and make no mistake about it. The pet food industry in the U.S. is a $6 billion a year industry and competition is cutthroat. It is big business and most of the major players, such as Kenl Ration and Gaines to name two are owned by large conglomerates and frequently are traded as mergers and new acquisitions are made and other divisions spun off to other companies. Purina, incidentally has about a 28% share and is the largest player in this field. The only reliable source of data comes from scientifically controlled studies and even then we may not know if we are being told the entire results of the studies or are receiving edited information. As an example Monsanto, who makes ethoxyquin, claims to have done a 5 year study on its efficacy and safety but yet this study has never been released and indeed is apparently not available.

Are you confused? You should be. I know I am. But I also know that unless there is proof that a product like ethoxyquin is causing all that is attributed to it, I will not jump on the anti-ethoxyquin bandwagon. Incidentally I have been using a product containing ethoxyquin for 10 years and have had no problems that did not have a logical explanation. As further food for thought I would like to mention the contents of an article I happened to come across in a 1984 issue of Equinox magazine. It talked about the problems of pollution in the Great Lakes and mentioned that Coho salmon in the lakes were dying in huge numbers due to cancers in the gills and jaw resulting from the pollution in the lakes. (It also mentioned that these salmon were still considered edible - a horrifying thought.)

On a separate but related note Dr. Jean Dodds, among others, has expressed a concern that the poor quality of our environment appears to have a correlation with the increase in auto-immune diseases in our dogs. Also, most of the problems attributed to ethoxyquin are auto-immune mediated ones.

Going back to the Great Lakes, if they are that polluted where did it come from? It came from industrial areas located on land. If the lakes are so affected, what about the land surrounding the industrial plants and how far are airborne pollutants carried? Scary stuff to think about isn't it?

Auto-immune diseases are definitely on the upswing. Are they hereditary or a product of an outside agency, chiefly the environment, or is it a mixed bag? Only time and research will tell. It may seem that I am an environmentalist. I'm not an active one but I am concerned about it as it has for me a compelling personal impact. My own opinion is that the environment is a significant factor in our animal's health problems which typically manifest themselves as skin disorders. In humans the respiratory system takes a beating. Look at the significant increase in allergies over the years, especially the increase in asthma and the increase in the death rate from asthma. (Being an asthma sufferer I'm keenly aware of the literature on it and the impact the environment has on it.) Has anybody blamed it on food additives only? My point is that our environment, both in the form of what we live in and in the form of what we ingest, plays a large part in our health and that of our animals. Is ethoxyquin the only culprit? I think not. But it may well be a player in the game.

Earlier on I was somewhat sanguine in my comments about all and sundry. However if all the fuss that Elaine Campbell has stirred up has its desired impact then additional research will be done and the question of adverse effects vs benefits of ethoxyquin answered. Unfortunately this is often the only way you can get big business and governments to overcome massive inertia and move.

When I set out to write this article my original intent had been to present scientific facts and fictions about ethoxyquin but I'm afraid I got on my soapbox and didn't know when to get down. Why indeed do we need ethoxyquin? Why not use something else? What are the problems with other antioxidants? Just what is an anti-oxidant anyway? How many of us really know just what we're getting all worked up about? I have had a few requests for some of my material on ethoxyquin and have sent out a package that in my opinion is a distillation of much that has been written in the scientific and veterinary community. I am not including any of Elaine Campbell's material as I assume that since you are concerned about ethoxyquin you have already read her letters which have been published, it seems, in just about every dog related periodical and Club Newsletter around.

ETHOXYQUIN

The question to be answered is why do we put ethoxyquin in our dog foods and that leads to the second question which is related to it, what does ethoxyquin do and why is it used over other products.

The thing about all natural claims made by some food manufacturers that their products do not contain preservatives is usually false. In actuality any food that contains a fat requires stabilization otherwise it will go rancid and probably kill the animal, or a person for that matter if they were to ingest rancid fats.

Vitamins C & E do act as preservatives but Vitamin E will deteriorate over time (elaborate on this) but in fact ethoxyquin will keep efficacious the Vitamin E in the product or has been added. It is worthwhile noting that the shelf life of products preserved with Vitamins C & E is shorter that products preserved with other agents, such as BHA or ethoxyquin. A question to be asked when buying a product is how long has it been sitting on the shelf. How old was it when the retailer obtained it and how long will it be sitting around before you have used it up? The article on cats contains a very good layman's description of what happens when fats break down and form peroxides. Make the point that not having additives is a desirable thing. There is no need to have artificial colors or flavors and such junk in our foods. However, back to antioxidants there is a necessity for it otherwise the food would not be able to stand up. It should be noted that unless vitamin E is added at the time the fat is refined it may be ineffective. Vitamin E will prevent the process of rancidity but will not reverse it. If rancidity has already set in it is too late. It should be noted that the addition of things like rosemary, comfrey leaves, kelp, etc. is not always beneficial although they have claims made that they have healthful properties. For example, dried kelp which has been added to the diet of race horses in the belief that it would somehow improve their performance, but the high iodine content found in some kelp has resulted in iodine toxicity. Therefore it is not being beneficial but detrimental to the animal. How many other "natural" additives work in the same way?

The important point to note is that anything in too large a dose can be harmful and not beneficial.

ETHOXYQUIN - For The Last Time

By now you must be tired of hearing about ethoxyquin. As a parting shot let's answer the following question - why do we put ethoxyquin in our dog foods?

Why do we need to use preservatives at all in pet foods? The answer is based on the chemistry of fat. Virtually all pet foods contain significant amounts of polyunsaturated fatty acids (PUFA) in order to satisfy the essential fatty acid contents of pet foods. Exposure of PUFA's to air and heat, even room temperature heat, results in oxidation taking place. Once oxidation starts the process is autocatalytic and proceeds at an ever increasing rate. This process, unless quenched, will completely denature fats and oils leading to the destruction of the essential fatty acids and of other fat soluble nutrients such as Vitamins A & E. This process not only lends an offensive odor to the fat but results in toxic compounds being formed.

The progress of rancidity can be delayed or prevented if antioxidants are added to the fat. These compounds prevent the reaction of oxygen with the fat, thus protecting the fat from breakdown. In order for them to be effective they must be added to the fat as early as possible. There are two classes of antioxidants - natural and synthetic.

Vitamin E is a natural antioxidant but there are at least seven different types of Vitamin E of which the alpha form is the commercially available form. But it is the gamma and delta forms which are more effective as antioxidants but also have very little biological activity. Therefore the alpha form is virtually the only commercial form of Vitamin E available. While Vitamin E acts as an antioxidant, it is consumed in the antioxidation process, eventually resulting in a vitamin E deficient food when conditions under which extensive fat oxidation can occur are present.

Due to the inherent instability of natural antioxidants, several synthetic antioxidants have been used to stabilize fats and oils, notably BHA, BHT and ethoxyquin (ETO). Not only do these products preserve fats but they also result in vitamin E retaining it efficacy over a period of time.

All natural claims made by some food manufacturers that their products do not contain preservatives are frequently false. These manufacturers purchase the fat in an already stabilized form from a refiner and ETO, BHA or BHT has already been added. In actuality any food that contains a fat requires stabilization otherwise it will go rancid and probably kill the animal, or a person for that matter, if they were to ingest rancid fats.

It is worthwhile noting that the shelf life of products preserved with Vitamins C & E is shorter that products preserved with other agents, such as BHA or ethoxyquin. A question to be asked when buying a product is how long has it been sitting on the shelf. How old was it when the retailer obtained it and how long will it be sitting around before you have used it up?

Not having additives in either human or pet foods is a desirable thing. There is no need to have artificial colours or flavours and such junk in our foods. However, back to antioxidants there is a necessity for them otherwise the food would not be able to stand up. It should be noted that the addition of things like rosemary, comfrey leaves, kelp, etc. is not always beneficial although they have claims made that they have healthful properties. For example, dried kelp which has been added to the diet of race horses in the belief that it would somehow improve their performance, but the high iodine content found in some kelp has resulted in iodine toxicity. Therefore it is not being beneficial but detrimental to the animal. How many other "natural" additives work in the same way?

The important point to note is that anything in too large a dose can be harmful and not beneficial.

As a final note, Purina, which has a 28% share of the pet food market, has been using ethoxyquin for about 30 years. We hear stories from people using premium foods having various problems. But we never hear stories from people using the more common products readily available in the supermarkets - products which also contain ethoxyquin. Why? Think about it. Is ethoxyquin really the culprit?

I hope you have found this series of articles informative, but even more important, you have found them thought provoking. The key point in all these articles has been that things are not always what they seem. The multiplicity of factors which can have an impact on a problem can be immense. I enjoyed writing them and hope you found them interesting and useful. Thank you for reading them.

 

 

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