TUESDAY, Feb. 21 (HealthDay News) -- Raw, or unpasteurized, milk causes 150 times more dairy product-related disease outbreaks than pasteurized milk. And states where the sale of raw milk is legal have twice as many outbreaks as states where it is illegal, according to a new U.S. Centers for Disease Control and Prevention study.

"This study shows an association between state laws and the number of outbreaks and illnesses from raw milk products," Dr. Robert Tauxe, deputy director of CDC's division of foodborne, waterborne and environmental diseases, said in an agency news release.

The 13-year review looked at more than 120 dairy product-related outbreaks that occurred in 30 states between 1993 and 2006. The outbreaks caused more than 4,400 illnesses, 239 hospitalizations and three deaths.

Raw milk products -- including cheese and yogurt -- caused 73 of the outbreaks (60 percent) and most of the 239 hospitalizations.

Some people mistakenly believe that raw milk is a healthier alternative to pasteurized milk, according to the U.S. Food and Drug Administration. Its website debunks the notion that raw milk is less likely than pasteurized milk to cause lactose intolerance, an inability to digest milk products.

Unless milk is pasteurized -- heated to kill harmful bacteria -- bacteria can accumulate in collected milk, multiply and cause illness, the researchers said.

The study found that 13 percent of patients in raw milk outbreaks were hospitalized, compared with 1 percent of those made ill by pasteurized milk products. This may be because raw milk outbreaks were all caused by bacteria, such as E. coli O157, that tend to provoke more severe illness, according to the study.

On the other hand, pasteurized milk and cheese outbreaks were often caused by milder infections, such as norovirus and Staphylococcus aureus.

Fifty-five of the outbreaks reviewed occurred in the 21 states where it was legal to sell raw milk at the time, the CDC found.

Young people were much more likely to get sick from raw milk products than pasteurized items. Where ages were available, people younger than age 20 accounted for 60 percent of patients in raw milk outbreaks, compared with 23 percent of patients in pasteurized milk outbreaks.

During the study period, about 2.7 trillion pounds of milk was produced in the United States. By comparing that amount to the estimated 27 billion pounds (1 percent) consumed raw, the study authors determined that raw milk products cause 150 times more outbreaks than pasteurized milk.

The study appears Feb. 21 in the journal Emerging Infectious Diseases, published by the CDC.

It's impossible for consumers to tell if raw milk is safe to drink by looking at, smelling, or tasting it, the CDC said.

"Restricting the sale of raw milk products is likely to reduce the number of outbreaks and can help keep people healthier. The states that allow sale of raw milk will probably continue to see outbreaks in the future," Tauxe said.

Study co-author Barbara Mahon, deputy chief of the CDC's Enteric Diseases Epidemiology Branch, said in the news release: "While some people think that raw milk has more health benefits than pasteurized milk, this study shows that raw milk has great risks, especially for children, who experience more severe illnesses if they get sick.

"Parents who have lived through the experience of watching their child fight for their life after drinking raw milk now say that it's just not worth the risk," she added.

More information

The U.S. Food and Drug Administration has more about raw milk.