Ethoxyquin Study Results Finally Approved by FDA

The FDA has finally signed off on  Monsanto’s ethoxyquin study, but  it’s a case of too little, too late to save ethoxyquin in the marketplace.

The five year study was undertaken at the height of the ethoxyquin controversy, and tested the antioxidant on dogs and several generations of puppies.

The results of the study show that ethoxyquin levels above the current tolerance in dog foods (150 parts per million) produced no adverse reproductive effects.

There was, however, an increase in a dark, reddish brown pigment in the liver of female dogs immediately after completing a 6-week lactation. The liver pigment was identified as protoporphyrin IX, a normal intermediate in the synthesis of heme.

Heme is the pigmented, iron-containing non-protein portion of the hemoglobin molecule. Heme binds and carries oxygen in the red blood cells, releasing it to tissues that give off excess amounts of CO2.This pigment was also associated with elevations in liver-related enzymes in the serum of a few animals.

During lactation, the female dogs consumed two to three times more food as a percentage of body weight than they did at a maintenance level. This increased food consumption likely contributed to the increased pigment deposition in the liver and in the elevated serum enzymes. This activity in lactating dogs may be reversible when food consumption returns to maintenance levels, but that’s a finding that must be further investigated.

The FDA’s Center for Veterinary Medicine (CVM) has requested that pet food manufacturers voluntarily lower the maximum level of ethoxyquin in complete dog foods to 75 parts per million, from the current 150 ppm. CVM believes that this will provide a greater margin of safety in lactating females and possibly in puppies.

The FDA is watching a study funded by the Pet Food Institute designed to show that ethoxyquin is an effective antioxidant at levels between 30 and 60 ppm in a complete dog food. If the study shows that ethoxyquin works just as well at lower levels, the FDA will consider further action.

In the meantime, the proof is in that ethoxyquin really is safe in the amounts used in dog foods (usually much less than what’s allowed). Because a few manufacturers scared dog breeders and the public with unfounded rumors of hazards, the pressure has been on to eliminate ethoxyquin from pet food.

It’s still one of the best antioxidants around–cost effective and many times more effective than vitamin E at scavenging free radicals that can harm your dog.

But the marketplace has spoken. Most pet food companies have ditched it, with Hill’s® Science Diet® being the most notable exception.

Ross Becker, 1998

New Study On Ethoxyquin

A major new four-year research  study has been completed which  determines the effects of ethoxyquin on dogs and their puppies. The study was started in 1991, and results were expected to be released to the Food and Drug Administration during the summer of 1995.

The study used a protocol approved by the Food and Drug Administration. Our research scientist looked at the protocol, and she said the study design meets all current scientific standards.

Monsanto, maker of Santoquin® ethoxyquin, sponsored the study. The research was conducted by an independent testing laboratory.

This expensive piece of research should provide a basis to judge the safety of ethoxyquin in dog food. Another study, part of the National Toxicology Program, is in line for government funding. This study will look at ethoxyquin’s safety for pets and people. No timetable has been set for the start of the study.

But it may be a moot point by the time the FDA releases the study or the National Toxicology Program acts: marketing pressures (not scientific research) has deemed ethoxyquin as ‘”bad,” and nearly all major manufacturers of pet food have switched from ethoxyquin to alternative preservatives.

Ross Becker, 1997

Preservatives Fight Cancer

If you think antioxidants (preservatives) aren’t good for you or your dog, read on.

According to an article in R&D Magazine, Andrew Dannenberg of Cornell Medical College has made an important discovery. He found that antioxidants BHA and BHT boost levels of a natural cancer-fighter. Laboratory animals were used in the tests, but these preservatives seem to have the same effect in humans.

BHA and BHT are antioxidants that are widely used in human and pet food. They “revved up” the gene for an enzyme that helps destroy carcinogens before they trigger tumors. In other words, they caused the gene to produce more of the enzyme which provided better protection against cancer-causing substances in the environment.

Crusaders Against Rancidity

Debbie Eldredge, D.V.M.

Antioxidants are preservatives  added to food to help protect the  fats, oils, and fat soluble compounds such as vitamins from undergoing decomposition. Unsaturated fats can mix with oxygen, “oxidation,” and become rancid.1 Once foods have started to decompose, the process speeds up with the good fats being influenced by the rancid fats.

Fats go rancid if they are exposed to heat (even room temperature) and to air (which contains oxygen).2  All pet foods have some unsaturated fats in them, and therefore, they all require some sort of antioxidant preservative.

A rancid fat is more than just foul smelling. Besides developing  a bad odor, foods lose their flavor and texture. More importantly, there can be harmful effects both from toxins formed in the “bad” fat and from the degeneration of essential vitamins, biotin and fatty acids. “Yellow Fat Disease” or steatitis was a common disease of cats back when they were fed a great deal of tuna with nothing to preserve the oils. The cats showed signs of extensive Vitamin E deficiency.3

Antioxidants come in both synthetic and natural varieties. Vitamin E, which requires some protection itself, is one of the best-known natural antioxidants. The form of Vitamin E most commonly used is alpha-tocopherol. Vitamin E helps to prevent oxidation by donating electrons to block the addition of oxygen to the unsaturated fats.

Vitamin C in the form of ascorbyl palmitate, a slightly modified form of the natural vitamin, is also an approved anti-oxidant. This compound acts by donating a hydrogen atom to the fats it protects. Ascorbyl palmitate is considered more effective than BHA or BHT in its antioxidant duties.1

The two vitamins are both considered to be natural antioxidants. They can be used in unrestricted amounts because of that designation. They are not as stable as the synthetic antioxidants and some of their usefulness may be destroyed in the processing of a food. Foods whose fat is totally preserved with natural antioxidants will have a shorter shelf life than most foods preserved with synthetic antioxidants.

The primary synthetic antioxidants are BHT (butylated hydroxytoluene), BHA (butylated hydroxyanisole) and ethoxyquin. These compounds have been in use since the 1950’s, and are on the list of Generally Regarded As Safe (GRAS) chemicals. Toxicity studies, particularly using BHT, have raised questions about the cancer-causing potential, but other studies have shown that the antioxidants help prevent cancer. Work is being done with antioxidants to try to counter the effects of aging, many of which are attributable to “free oxygen radicals.”

The synthetic antioxidants have a restricted use level which is 150 parts per million for ethoxyquin, and 200 parts per million for BHA and BHT. Ethoxyquin also tends to stand up to the rigors of food processing very well. Because of its efficiency and stability, ethoxyquin greatly increases the shelf life of foods to which it is added.1

It is quite clear that unless we cook fresh meals for our pets every day, we need to have some type of antioxidant added to their foods. Synthetic or natural, which is better? Only time and research will tell.

References

1. Hilton, John, PhD. “Antioxidants: function, types and necessity of inclusion in pet foods.  Canadian Veterinary Journal, Vol. 30, Aug., 1989, pg. 682.
2. Kallfelz, F., DVM. “Probing preservatives.” Cat Fancy, Nov., 1989.
3. Corbin, J., PhD. “Ethoxyquin answers for pet food clients.” Pet Store Marketing (PSM). Oct., 1989, pg. 26.

Ethoxyquin Study Results Finally Approved by FDA

The FDA has finally signed off on  Monsanto’s ethoxyquin study, but  it’s a case of too little, too late to save ethoxyquin in the marketplace.

The five year study was undertaken at the height of the ethoxyquin controversy, and tested the antioxidant on dogs and several generations of puppies.

The results of the study show that ethoxyquin levels above the current tolerance in dog foods (150 parts per million) produced no adverse reproductive effects.

There was, however, an increase in a dark, reddish brown pigment in the liver of female dogs immediately after completing a 6-week lactation. The liver pigment was identified as protoporphyrin IX, a normal intermediate in the synthesis of heme.

Heme is the pigmented, iron-containing non-protein portion of the hemoglobin molecule. Heme binds and carries oxygen in the red blood cells, releasing it to tissues that give off excess amounts of CO2.This pigment was also associated with elevations in liver-related enzymes in the serum of a few animals.

During lactation, the female dogs consumed two to three times more food as a percentage of body weight than they did at a maintenance level. This increased food consumption likely contributed to the increased pigment deposition in the liver and in the elevated serum enzymes. This activity in lactating dogs may be reversible when food consumption returns to maintenance levels, but that’s a finding that must be further investigated.

The FDA’s Center for Veterinary Medicine (CVM) has requested that pet food manufacturers voluntarily lower the maximum level of ethoxyquin in complete dog foods to 75 parts per million, from the current 150 ppm. CVM believes that this will provide a greater margin of safety in lactating females and possibly in puppies.

The FDA is watching a study funded by the Pet Food Institute designed to show that ethoxyquin is an effective antioxidant at levels between 30 and 60 ppm in a complete dog food. If the study shows that ethoxyquin works just as well at lower levels, the FDA will consider further action.

In the meantime, the proof is in that ethoxyquin really is safe in the amounts used in dog foods (usually much less than what’s allowed). Because a few manufacturers scared dog breeders and the public with unfounded rumors of hazards, the pressure has been on to eliminate ethoxyquin from pet food.

It’s still one of the best antioxidants around–cost effective and many times more effective than vitamin E at scavenging free radicals that can harm your dog.

But the marketplace has spoken. Most pet food companies have ditched it, with Hill’s® Science Diet® being the most notable exception.

Ross Becker, 1998