MILWAUKEE — Dairy products accounted for more foodborne-illness hospitalizations over an 11-year period than 16 other commodity foods, says a new study from the Centers for Disease Control and Prevention.
One of the big concerns is raw milk and other unpasteurized dairy products, John Painter, one of the study's authors, said in an interview last week.
Consumption of raw milk has pitted regulators against consumers who believe the health benefits of drinking unpasteurized milk straight from the farm outweigh risks of foodborne illness caused by bacteria such as E. coli.
The study, scheduled to be published in the March edition of Emerging Infectious Diseases Journal, also says leafy vegetables and dairy products were among the top contributors to foodborne illnesses.
"What really jumped out at us was the large number of illnesses associated with vegetables and produce. It's a food that's generally very safe and is part of a healthy diet. We want people to eat more vegetables," Painter said.
Dairy products ranked second, resulting in 1.3 million illnesses and 10 percent of foodborne-illness deaths from 1998 through 2008. Dairy products accounted for the most hospitalizations, 16 percent, followed by leafy vegetables, 14 percent, poultry, fruits and nuts.
Milk, cheese and ice cream are big contributors to foodborne illness, the Center for Science in the Public Interest, a Washington, D.C., consumer advocacy group that studies food issues, said about the CDC report.
"The risk from dairy products has increased in recent years with the rise in popularity of unpasteurized raw milk and cheeses.
"People who consume unpasteurized dairy products have no protection from hazards like E. coli O157 and salmonella that are commonly found in dairy cattle," the Center for Science in the Public Interest said.
The study used data from thousands of illness outbreaks to estimate the number of illnesses attributed to each of 17 food commodities. Over the 11-year period studied, 277 people died from foodborne illnesses linked to poultry and 140 died from illnesses linked to dairy products, according to the study.
Since a large volume of dairy products is consumed in the United States, even infrequent contamination of commercially distributed products can result in many illnesses, the study noted.
The data didn't distinguish between pasteurized and unpasteurized products, which critics said was a flaw in the study.
"To say that raw dairy is likely to cause many foodborne illness outbreaks, when the study doesn't even have any statistics to back that up, is speculation," said Kimberly Hartke, spokeswoman for the Real Milk Campaign, a Washington, D.C.-based advocate for raw milk products.
But a CDC study published a year ago found the rate for disease outbreaks caused by raw dairy products was 150 times higher than for pasteurized milk. That study said that milk consumption was responsible for 121 disease outbreaks, causing 4,413 illnesses, 239 hospitalizations and three deaths from 1993 to 2006 - and that raw milk products were the cause of 60 percent of the outbreaks.
With pasteurization, milk is briefly heated to a temperature high enough to kill off most bacteria. Food safety officials say it's essential, since pathogens in untreated milk may cause severe illness or even death.
"Whenever we see a rise in outbreaks or illnesses linked to dairy, we immediately start thinking about unpasteurized dairy products," said Sarah Klein, senior attorney for the food safety program at the Center for Science in the Public Interest.
"Raw milk is one of the most dangerous foods in existence. I would put it up there with raw sprouts and raw ground beef," Klein said.
Each year roughly 48 million people, 1 in 6, get sick from food eaten in the United States. That includes 128,000 hospitalizations and 3,000 deaths, according to previous CDC estimates.
In the new study, the agency said the leading cause of foodborne illness in the U.S. is norovirus, a genetically diverse group of viruses transmitted by fecal material and often associated with improper hand-washing.
Sick food handlers caused 53 percent of the foodborne norovirus outbreaks by contaminating food, and they may have contributed to an additional 29 percent of the outbreaks, according to the study.
More deaths, 19 percent, were attributed to poultry than any other of the food commodities. The broader category of meat and poultry combined accounted for 29 percent, while the broader category of produce accounted for 23 percent.
The largest single foodborne illness outbreak was 1,644 illnesses resulting from the consumption of pasteurized milk. But a disproportionate number of outbreaks were linked to raw milk products, according to the study's authors.
"We know that many of the outbreaks were due to unpasteurized milk," Painter said.
In a separate study by the Center for Science in the Public Interest, ice cream and cheese were named among the top-10 causes of foodborne illnesses linked to outbreaks.
Pasteurization isn't a "silver bullet" against pathogens either, according to the Center for Science in the Public Interest, especially as contamination can occur after a product has been treated.
"But what's more of a grave and immediate concern to us is the apparent rise in the popularity of raw milk products, whether it's milk or cheese," Klein said.
Dairy industry officials said they weren't alarmed by the CDC findings because they didn't show a pattern of problems at processing facilities, and the industry has a good reputation.
"I don't see a lot of dairy product recalls," said Marianne Smukowski, dairy safety/quality applications coordinator at the Wisconsin Center for Dairy Research at University of Wisconsin-Madison.