CHICAGO -- Antibiotic-free foods are not necessarily safer, according to an Institute of Food Technologists study to be released tomorrow.
The study, conducted by a panel of food scientists and microbiologists, aims for the heart of the marketing campaigns in the past decade by organic food advocates who have suggested there is an overuse of antibiotics and that antibiotic-free foods are better for human consumption.
One such group is the Organic Trade Association, based in Greenfield, Mass., which represents many of the nation's organic food producers. The association notes 10 studies from 2000 and 2001 of antibiotic use in farming to support its stand that antibiotics have been abused by American farmers.
"What we are trying to do is bring a balance to the discussion," said Michael Doyle, chairman of the panel assembled by the Chicago-based Institute of Food Technologists and a professor and director of the Center for Food Safety at the University of Georgia. "The study does raise questions about those groups using this as a basis for their promotion of organic and natural products."
Such promotions seem to have helped drive sales. The study comes as sales of organic products are skyrocketing, rising to $14 billion in 2005 from $6 billion in 2000, according to data compiled by the Organic Trade Association.
Doyle and the Institute of Food Technologists say they don't dismiss concerns about overuse of antibiotics or antimicrobials, such as cleaners and disinfectants.
However, they do warn against reducing the levels of antibiotic use in food production, saying eliminating those drugs may have little effect on bacteria that might develop resistance to antibiotic treatment but would hurt animal health and food production.
"The fact is that if we cut back on antibiotics in animals raised in food production, we would see a marked increase in food costs because we're going to have a lot of animals we're not able to treat effectively," he said.
Overuse by humans, not regular use in animals, creates strains of resistant bacteria that hurt humans, the panel found.
"Prior human exposure to antibiotics is the greatest factor for acquiring an infection with antibiotic-resistant bacteria," said Doyle, not routine treatment of animals with antibiotics.
Unlike previous studies that were narrowly focused, Doyle said, the institute's examination explores 20 years' worth of research into antibiotic and antimicrobial resistance.
The study was funded by the Institute for Food Technologists Foundation, a nonprofit scientific and educational group with 22,000 members working for the food industry, academia and government.
The panel was made up of microbiologists and food scientists from leading universities. Besides the University of Georgia, panelists were drawn from Rutgers University, Iowa State University, the University of Tennessee, the University of Minnesota and the University of Maryland. Many Food and Drug Administration food laboratories are at Iowa State.
Doyle dismissed possible concerns about the food scientist members of the panel being too closely linked to the food industry, noting that about one-third of the panel was made up of microbiologists.
Barbara Haumann, a spokeswoman for the Organic Trade Association, said the group is not trying to make safety claims.
"It is not that foods are safer," she said, adding that the organization has not updated the list of studies since assembling it in 2002.
But "the overuse of animal antibiotics does lead to superstrains of antibiotic-resistant bacteria," she said. "Organic producers chose not to routinely use antibiotics because the studies have shown a concern."
Doyle said animal antibiotics may make food safer to eat in some instances.
Doyle and the group said they are not trying to change the eating habits of Americans.
"People have their preference. It is not our goal to dissuade people from buying organic or natural foods," he said.
"We want to put the entire picture in perspective so people can better appreciate the big picture and the science behind it."
John Schmeltzer writes for the Chicago Tribune.