How We Establish Biotech Crop Safety: Product Safety for Food and Feed

By K. Sauer 3/30/2009

What is substantial equivalence?

The concept of substantial equivalence is widely accepted as the basis for proving the safety of biotech crops. It was introduced by the Organization for Economic Cooperation and Development (OECD) in 1993, and has been validated by many international scientific and governmental organizations since.

According to the Biotechnology Industry Organization's (BIO) Web site, "simply stated, substantial equivalence holds that a biotech food is as safe to consume as an existing food with the same compositional and nutritional characteristics and a history of safe use." Basically, if the biotech crop has the same make-up and nutrients as its conventional counterpart, it's considered as safe as that counterpart. Learn more about the history of and details behind substantial equivalence.

The safety of biotech crops is often questioned by anti-GM groups and sometimes consumers. But biotech crops undergo more testing and oversight before commercialization than any other agricultural products, including conventional crops.

Part one of this series outlined the role of Monsanto’s Product Characterization and Detection Methods Center in determining whether a biotech crop is as safe as its conventional equivalent. But once that testing is complete and data has been generated, the Product Safety Center takes over for further testing—this time to conduct safety assessments to determine food and feed safety.

Compositional Analysis

“Essentially, with the comparative safety assessment we’re trying to generate data to determine if the new product is substantially equivalent to products that have a history of safe consumption, with the exception of the introduced trait,” Kevin Glenn, Monsanto’s product safety center lead, said. “The underlying concept, then, is any differences are subjected to supplemental safety assessment.”

This safety assessment includes several components, including composition analysis and animal performance assessments.

For the composition analysis, the team characterizes the forage part of the plant, which is what animals eat, and compares it to its conventional counterpart to ensure they’re compositionally the same. When analyzing the composition of the grain, they put it through an extensive array of tests looking at the known nutrients and antinutrients. These extensive tests are done because grain is the major component of animal feed rations and is what typically enters the human food chain.

“We basically are establishing the concept that new product X is substantially equivalent to products that we already know how to process and consume and have a history of safe consumption,” Glenn said.

Animal Performance Assessments

But even if Monsanto knows the new biotech products are compositionally the same as their conventional counterparts, Monsanto generates additional assurances that food and feed from these products are as safe as food and feed from existing conventional products--through animal performance assessments.

“With many of the products we work with—corn, soy, cottonseed—most of what is grown commercially is used for animal consumption,” Glenn said. “So, another part of the Product Safety Center is conducting a standard 42-day broiler study on chickens.”

This study looks at the development and size of the animal as it’s fed the product with the new gene inserted.

But why chickens?

“They’re actually an incredible species, if you think about it,” Glenn said. “They start at around 35-45 grams and within six weeks become a 2-3 kilogram bird. That’s incredible growth, and they’ve been bred so selectively for that kind of growth that almost any perturbation in the nutrients or antinutrients that might be in a new product would cause an adverse growth rate.

“Just comparing the feed efficiency and growth in a study with feed from biotech crops to one with conventional crops gives a pretty good idea of whether there are any  important differences related to the new product,” he continued.

In addition to the growth and development testing in the broiler chicken study, the team also conducts a 90-day rat feeding study with most products, which is a toxicology study.

During the course of the 90-day toxicology study, Glenn said they can conduct well over a hundred different assessments on things such as blood chemistries, tissue pathology and organ weights. This helps toxicologists determine if the new product is having any undesirable effects on the health or physiology of the animals that might predict potential adverse effects for humans.

“All of these assessments have some known association with important health or physiological functions in the animal that would be impacted and give us a clue if there is some toxicity,” Glenn said.

“For example, if there’s a perturbation in liver weight, then we would look at the liver tissue and blood chemistry to see if liver enzymes have also been inadvertently changed,” he continued. “That might give us a clue there might be some liver toxicity that needs further assessment to see if it is related to the introduction of the biotech trait into the crop.”

But according to Glenn these rat toxicology studies aren’t very exciting to him because for biotech products, he finds it’s a fairly boring result—nothing happens.

This is more impressive when you consider today’s toxicology assessments look at absolute extremes to give an added assurance of safety. For example, in developed countries, diets are diverse and most people don’t eat large amounts of a single grain, but the rats in the study do. If the rats don’t show any issues from such a diet, it can be assumed a human, who would likely eat foods from this biotech crop as a smaller portion of their diet, would also not have any issues.

To date, no commercialized biotech products have ever been associated with an actual hazard to humans or animals. Continued introduction of biotech products will be subjected to the same thorough testing and analysis done by not only Monsanto scientists, but many others around the world to ensure only products that are as safe as their conventional counterparts will ever make it to market.