Donate
JOIN
Protecting Our Food, Farms & Environment
toggle menu
Campaigns
Trump Watch
Hawai'i CFS
CFS Hollywood

National Academy of Sciences to Release Report on Unintended Effects of Genetically Engineered Crops

July 26, 2004

In anticipation of the release of the NAS report on unintended effects due July 28, Center for Food Safety senior scientist Dr. Doug Gurian-Sherman has prepared a briefing paper to assist you in understanding the complexities of this issue. The following is an excerpt of that primer. Download the full analysis here.

The federal agencies primarily responsible for regulating genetically engineered food, the Food and Drug Administration, Department of Agriculture, and the Environmental Protection Agency, have requested that the National Academies of Science study and report on the regulation of unintended effects of genetically engineered crops to help them better determine the safety of these foods for humans and animals.

Unintended effects can include increases in harmful substances such as toxicants, anti-nutrients, and allergens that food crops normally produce in lower quantities. New or previously unidentified substances could also be unintentionally produced as plants are particularly adept at making such substances. That many of these substances have powerful effects is demonstrated by the host of drugs, and even pesticides, that are derived from plant substances. Many of these substances are absent or at low levels in the edible parts of food crops (or are removed by processing) due to millennia of selection and breeding–although their inactive genes may still be present and could be activated by genetic engineering.

Unintended changes due to genetic engineering are common in crops. There are dozens of reports of unintended effects in the scientific literature despite the fact that such effects are typically not recorded because they are not the object of study. It is widely understood that the vast majority of initial transgenic plants are typically rejected due to unintended changes. Some of those changes are due to the genetic engineering process itself and may be removed during further breeding, but many are due to the new gene and cannot be removed. Typically, information about the nature of these defective plants is not made public because they are discarded by the crop developers. However, the unintended outcomes that are easily identified and discarded by genetic engineering companies are not synonymous with the typically “invisible” traits that may harm people.

Examination of unintended effects in genetically engineered crops shows that:

  • Unintended effects/changes in biotech crops are common and many have been noted in scientific literature. Yet it is likely that most unintended effects are never reported because they are rarely the object of research.
  • Unintended harmful changes have occurred in several traditionally bred crops including potato, celery, and squash. The National Academy of Sciences has previously cited those incidents in conventional crops to support testing for unintended effects in genetically engineered crops.
  • Even widely recognized and agreed upon potential unintended effects have not been consistently measured in genetically engineered foods that have passed FDA review.
  • Unintended changes may also occur in the engineered gene or protein, and are not always easily detected. Detection of changes in the genetically engineered protein is not adequately addressed in current safety testing protocols.
  • Potentially harmful unintended effects have been noted in non-commercial engineered tomatoes, potatoes, and yeast. Biotech tomato plants passed safety review by FDA only to be found by academic scientists to be capable of accumulating substantially more toxic heavy metals than a conventional variety.
  • Due to limited and inadequate safety testing requirements, unintended changes can easily go undetected. In several instances unintended effects have been discovered years after regulatory review.
  • The mechanisms causing unintended effects in genetically engineered crops and the likelihood that harmful changes will occur have not been widely studied, are not well understood, and cannot be predicted
  • The continuing discovery of new and potentially harmful substances in crops that could be inadvertently increased by genetic engineering tells us that merely testing a few known crop toxicants and anti-nutrients is not adequate to assure public safety

For all of these reasons, a rigorous approach to testing for harmful changes in genetically engineered crops should be taken. Center for Food Safety makes the following recommendations:

  • Legislation requiring FDA to approve the safety of genetically engineered crops and to develop detailed testing guidelines to assure that the best test methods are used;
  • Testing should be conducted for changes in the amounts of all toxicants, anti-nutrients, and allergens known to be produced by the crop;
  • Testing of whole genetically engineered crops should be conducted, not just testing of the purified genetically engineered protein;
  • New methods to identify changes in the crops need to be validated for use in risk assessment and incorporated into regulatory requirements. Any observed changes in genetically engineered crops need to be identified and assessed for risk.

Download Full Analysis