The National Milk Producers Federation, Arlington, Va., said a food safety study from the U.S. Centers for Disease Control and Prevention presents a powerful argument against efforts to ease restrictions on the sale of raw milk to consumers.

According to the study, which will appear in the January 2015 issue of the CDC journal Emerging Infectious Diseases, the average number of foodborne illness outbreaks associated with drinking unpasteurized milk has more than quadrupled in recent years, as states approved more laws allowing retail sale of raw milk.

From 2007 to 2012, the study reported 81 raw milk-associated foodborne illness outbreaks nationwide, or an average of 13 per year. The outbreaks, which sickened nearly 1,000 people and sent 73 to the hospital, were concentrated in states where raw milk sales are legal.

By contrast, an earlier study, covering 1993 to 2006, found an average of only three foodborne illness outbreaks per year associated with raw milk consumption.

 “The more raw milk that is available to people, the more people become sick; the connection is crystal clear,” said Beth Briczinski, NMPF’s vice president for dairy foods and nutrition. “Since 2004, eight more states have allowed raw milk sales, and food-borne illnesses associated with raw milk consumption have increased.”