[For a brief overview explaining the inadequacy of the food testing accepted by present regulations and the testing required to minimize health hazards, see "Substantial equivalence versus scientific food safety assessment". /The editor]


(This is a condensed version of an article with the same name /the editor/)

John Fagan, Ph.D., Professor of Molecular Biology, Maharishi University of Management

The concept of substantial equivalence has been used in Europe, North America, and elsewhere around the world as the basis of regulations designed to facilitate the rapid commercialization of genetically engineered foods. Genetically engineered foods classified as substantially equivalent are spared from extensive safety testing on the assumption that they are no more dangerous than the corresponding non-genetically engineered food (1). Using similar arguments, genetically engineered foods classified as substantially equivalent are not required to be labeled as genetically engineered (2).

The effect of these regulations has been to allow genetically engineered foods to enter the market place without sufficient testing to assure safety and without sufficient labeling to allow consumers to decide for themselves whether or not to purchase and eat these novel foods. The health of people is thus being placed at risk.


At first glance the term substantially equivalent implies that two foods are equivalent in all characteristics that are of importance to the consumer-safety, nutrition, flavor, and texture. However, in actual practice the investigator compares only selected characteristics of the genetically engineered food to those of its non-genetically engineered counterpart. If that relatively restricted set of characteristics is not found to be significantly different in these two, the genetically engineered food is classified as substantially equivalent to the corresponding non-genetically engineered food and is required to be neither tested further nor labeled as genetically engineered.

The argument supporting this practice is that since most of the characteristics of a particular genetically engineered food are similar to those of its non-genetically engineered counterpart, it must be the case that the genetically engineered food is substantially equivalent to its non-genetically engineered counterpart with respect to all characteristics relevant to the consumer. This is obviously a fallacious argument, and should not be used as the basis for avoiding more extensive testing and for avoiding the labeling of genetically engineered foods. Most critically, if characteristics important to food safety are not evaluated directly, the safety of consumers will be in jeopardy.

Inadequate Testing

In practical terms, if a genetically engineered food is different from its non-genetically engineered counterpart, that difference will be detected only if a test is carried out that is capable of measuring the specific characteristic which is different between the two. Therefore, if the tests prescribed for determining substantial equivalence do not include one or more tests capable of detecting what happens to be different in the genetically engineered food compared to its non-genetically engineered counterpart, the genetically engineered food will be wrongly classified as substantially equivalent to its non-genetically engineered counterpart.

Currently, the testing procedures required in Europe, North America and elsewhere consist almost exclusively of specific chemical and biochemical analytical procedures designed to quantitate a specific nutrient or a specific toxin or allergen.

Unpredicted Side-Effects

Important as these studies are, however, they fail to even begin to assess one very substantial class of risks that are inherent in genetically engineered foods. That class of risks consists of health hazards resulting from the unanticipated side-effects of genetic engineering. Such testing schemes are completely incapable of detecting unsuspected or unanticipated health risks that are generated by the process of genetic engineering, itself.

It is a scientific fact that the process of genetic engineering often gives rise to unanticipated side-effects. These can - and have been shown to - introduce unforeseen allergens and toxins into foods and unexpectedly reduce nutritional value. Not every genetically engineered food will have these problems, but there is a finite probability that any given genetic modification will lead to unanticipated side-effects that result in food characteristics that threaten the health of consumers.

Clinical Tests Needed

Given that genetic engineering can introduce unexpected health hazards into foods, it is logical that every genetically engineered food should be subjected to tests that are capable of detecting a wide range of unforeseen health threats. Yet, at present, the liberal use of the concept of substantial equivalence makes it possible to avoid such testing.

What additional tests are required? Tests are needed that are capable of screening for a wide range of diverse allergens and toxins. It is not possible within the scope of this document to discuss in detail the deficiencies in the current system and the measures required to rectify this situation. (This subject is discussed in Assessing the Safety of Genetically Engineered Foods, by the author) In short, what is missing in current testing programs is clinical tests in which humans are fed the genetically engineered food in question both short-term and long-term.

Human tests are of primary importance because animals are poor models for assessing the human health impacts of foods. In particular, animal tests provide virtually no useful information regarding the allergenicity of food to humans.

Only clinical tests have the broad specificity and relevance to human physiology needed to detect the wide range of allergens and toxins that might result from unexpected side-effects of the genetic engineering process. Without such tests, the full range of allergens and toxins that can be introduced via the process of genetic engineering cannot be detected, and without such tests, it is impossible to assure that a given genetically engineered food is in fact free from health-damaging characteristics.

[For a brief overview of the differences between the testing accepted according to the principle of Substantial Equivalence and the testing required to minimize health hazards, see "Substantial equivalence versus scientific food safety assessment". /the editor]


Need for Labeling

Even if more stringent testing is implemented, it is essential that genetically engineered foods be labeled as genetically engineered. No testing scheme can ever be exhaustive. Therefore some residual risk of undetected health damaging characteristics will always remain with foods that have been produced using a technique, such as genetic engineering, that is capable of introducing into a food a wide range of unexpected side effects. Labeling these foods as genetically engineered allows consumers to choose for themselves whether or not to accept this residual risk.

Industry has stiffly opposed proposals that would have required genetically engineered foods to undergo clinical testing similar to that which is standard for novel food additives. The expense and time required for testing is perceived as a hindrance to commercialization of genetically engineered foods. However, in the long run, more rigorous testing will be good, not only for consumers, but also for industry.

Without such testing some genetically engineered foods that seriously damage the health of consumers will enter the market. Thus, this short-sighted approach to safety assessment clearly favors commercial interests while placing the health of the entire population at risk. Not only does this abrogate scientific responsibility and basic humanitarian values, but it is also bad business, because it will inevitably lead to loss of consumer confidence in genetically engineered foods.


Literature Cited

1. Regulation EC /95 of the European Parliament and of the Council Concerning Novel Foods and Food Ingredients,
Article 3.4.
2. Regulation EC /95 of the European Parliament and of the Council Concerning Novel Foods and Food Ingredients,
Article 8.1.
3. OECD, DSTI/STP (95)18, Paris, 1995, pages 79-87.
4. Does Medical Mystery Threaten Biotech? Science, P age 619, 2 November 1990
5. An Investigation of the Cause of the Eosinophilia-Myalgia Syndrome Associated with Tryptophan Use, New England Journal of Medicine, 323: 357-365, 1990.
6. EMS and Tryptophan Production: A Cautionary Tale, TIBTECH, 12:346-352, 1994.

Copyright 1997 John Fagan. Published with the permission of the author..

"Genetically Engineered Food - Safety Problems"
Published by PSRAST

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