A new study published in the Centers for Disease Control and Prevention’s (CDC) journal, Emerging Infectious Diseases, found that the rate of outbreaks caused by unpasteurized milk (raw milk) and unpasteurized milk products was 150 times greater than outbreaks linked to pasteurized milk.  In addition, the study revealed that states where raw milk sales are legal had more than twice the rate of outbreaks as states where it was illegal.

The 13-year study, involved a review of dairy product outbreaks from 1993 to 2006 in all 50 states.  The authors compared the amount of milk produced in the United States during the study period (about 2.7 trillion pounds) to the amount that CDC estimates was likely consumed raw (1 percent or 27 billion pounds) to determine the 150 times higher rate for outbreaks caused by raw milk products.  Raw milk products include cheese and yogurt.

The study included 121 dairy–related disease outbreaks, which caused 4,413 illnesses, 239 hospitalizations and three deaths. In 60 percent of the outbreaks (73 outbreaks) state health officials determined raw milk products were the cause.  Nearly all of the hospitalizations (200 of 239) were in those sickened in the raw milk outbreaks.  These dairy-related outbreaks occurred in 30 states, and 75 percent (55 outbreaks) of the raw milk outbreaks occurred in the 21 states where it was legal to sell raw milk products at the time. The study also reported that seven states changed their laws during the study period.

For a consumer, it is impossible to tell if raw milk is safe to drink by simply looking at, smelling, or tasting it.  Even under ideal conditions of cleanliness, the process of collecting milk introduces some bacteria.  Unless the milk is pasteurized, these bacteria can multiply and grow in the milk and cause illness in those who consume it.  Pasteurization involves heating milk to kill disease-causing bacteria.

“This study shows an association between state laws and the number of outbreaks and illnesses from raw milk products,” said Robert Tauxe, M.D., M.P.H., deputy director of CDC’s Division of Foodborne, Waterborne and Environmental Diseases (DFWED). “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.”

The study also found that the raw milk product outbreaks led to much more severe illnesses, and disproportionately affected people under age 20. In the raw milk outbreaks with known age breakdowns, 60 percent of patients were younger than age 20, compared to 23 percent in outbreaks from pasteurized products.  Because of their underdeveloped immune systems, children are more likely than adults to get seriously ill from the bacteria in raw milk.

“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,” said study co-author Barbara Mahon, M.D., M.P.H., deputy chief of CDC’s DFWED Enteric Diseases Epidemiology Branch. “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.”

Additional information on evidence-based scientific studies covering the benefits and risks of raw milk consumption can be found HERE (pdf).

According to Food Safety News, since the end of the study’s review period of 1993 to 2006, there have been an additional 56 foodborne illness outbreaks associated with raw milk and raw milk products. 

According to Jay-Russell, nearly all instances of outbreaks from pasteurized dairy occur because of contamination after the pasteurization process.

This year, Indiana, New Jersey, Iowa, Idaho, New Hampshire, Kentucky and Wisconsin have all considered changes to their raw milk sales laws. The majority of the bills under review would either permit the sale of raw milk where currently illegal, or remove certain restrictions on its sale in states where it’s already permitted.

Federal law restricts the transport of raw milk across state lines for sale, though consumers are free to travel across state lines to purchase milk and take it home, and there is no law against consuming unpasteurized milk.

The push for loosened raw milk sales rules across many states runs counter to the best scientific recommendations the CDC and Food and Drug Administration can make based on the available data, Jay-Russell said. Many raw milk proponents argue that raw milk provides nutrients and numerous health benefits negated by the pasteurization process, while many food scientists say there’s no credible scientific evidence for any of those claims.

“It’s [the CDC and FDA’s] charge to look at the health statistics and inform the public and help policy makers create policy that makes sense,” Jay-Russell said. “But there’s a push-back. Some groups don’t want government influence over food, so it makes it a much more political debate than a scientific one.”