One of the most contentious issues surrounding the controversy about genetically engineered (GE) foods is whether there may be long-term safety risks, and whether current regulations are sufficient to prevent such risks from occurring.
As I briefly discussed in my last post, major science organizations have said that some GE foods produced by current methods could be harmful, and have provided some examples of the kinds of harm that might occur.
The current situation
Most corn, soybeans, and cotton in the U.S. are engineered to contain one or several genes for insect or herbicide resistance. Many more types of engineered genes are in the works. Photo by danellesheree.
No long-term safety tests in animals are required by any regulatory agency. In some circumstances, 90-day, so-called sub-chronic tests may be required in Europe. But 90 days is far short of the one to two years that usually satisfy long-term safety test requirements.
Long-term experiments are required for products like drugs and chemical pesticides, and sometimes for food additives. They are considered important or necessary for determining harm that may take years to develop, such as cancers, Parkinson’s disease, and so on.
Recently, the American Association for the Advancement of Science (AAAS) Board of Directors cited a review of several long-term and multi-generational studies by Snell and colleagues in support of their claim that GE foods are safe and well tested.
The study cited by the AAAS Board has made the rounds in recent months, being used to claim that long-term studies show that GE is safe, and that shorter-term tests are sufficient.
The study authors extrapolate from the reviewed research that GE crops can be safely used in foods, based on currently required tests. For example, at the end of the paper’s abstract they write: “The studies reviewed present evidence to show that GM plants are nutritionally equivalent to their non-GM counterparts and can be safely used in food and feed.” They also conclude that 90-day tests are usually sufficient, and even these may not always be needed.
The study makes some useful contributions, but a careful reading shows that it contains some serious flaws. These limitations — some of which involve the interpretation of the results by the authors — eliminate the value of this study for drawing general conclusions about the safety of GE foods, or the adequacy of current shorter tests to reveal long-term risks from engineered foods.