Does Genetic Modification Work?

The answer to this question depends on whom you ask. If you ask the Union of Concerned Scientists, the answer is no. Just out is this group's report, Failure to Yield: Evaluating the Performance of Genetically Engineered Crops. From a statement released with the report:

For years the biotechnology industry has trumpeted that it will feed the world, promising that its genetically engineered crops will produce higher yields.

That promise has proven to be empty, according to Failure to Yield, a report by UCS expert Doug Gurian-Sherman released in March 2009. Despite 20 years of research and 13 years of commercialization, genetic engineering has failed to significantly increase U.S. crop yields.

Failure to Yield is the first report to closely evaluate the overall effect genetic engineering has had on crop yields in relation to other agricultural technologies. It reviewed two dozen academic studies of corn and soybeans, the two primary genetically engineered food and feed crops grown in the United States. Based on those studies, the UCS report concluded that genetically engineering herbicide-tolerant soybeans and herbicide-tolerant corn has not increased yields. Insect-resistant corn, meanwhile, has improved yields only marginally. The increase in yields for both crops over the last 13 years, the report found, was largely due to traditional breeding or improvements in agricultural practices.

The UCS report comes at a time when food price spikes and localized shortages worldwide have prompted calls to boost agricultural productivity, or yield -- the amount of a crop produced per unit of land over a specified amount of time. Biotechnology companies maintain that genetic engineering is essential to meeting this goal. Monsanto, for example, is currently running an advertising campaign warning of an exploding world population and claiming that its "advanced seeds... significantly increase crop yields..." The UCS report debunks that claim, concluding that genetic engineering is unlikely to play a significant role in increasing food production in the foreseeable future.

Its conclusion: traditional genetic crosses outperform genetically modified crops by a wide margin. Agricultural biotechnology giant Monsanto, as you might guess, has a rather different take on this issue, one that now faces a serious challenge.

Marion Nestle is a professor in the Department of Nutrition, Food Studies, and Public Health at New York University. She is the author of Food Politics, Safe Food, What to Eat, and Pet Food Politics.