Is Raw Milk Dangerous?

Jars of raw milk in a row. (Photo: Lisa Brewster [CC BY-SA 2.0]/Flickr)

Yesterday, the Centers for Disease Control and Prevention (CDC) sent out a news release entitled, Majority of dairy-related disease outbreaks linked to raw milk. In the report, the CDC claims that a new study, which reviewed the last 13 years, found that in areas where raw milk is legal, "outbreaks" double. The agency also pointed out that all of those hospitalized from dairy-borne illnesses were sickened specifically by raw milk.

Dr. Robert Tauxe, deputy director of CDC’s Division of Foodborne, Waterborne and Environmental Diseases, said, "This study shows an association between state laws and the number of outbreaks and illnesses from raw milk product. 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.”

Two other points made in the news release were that 13 percent of patients in raw milk outbreaks were hospitalized compared to 1 percent in pasteurized milk outbreaks. The authors of the study guessed this was because E. coli 0157 caused it. Plus, the authors of the study said that pasteurized milk and cheese outbreaks were caused by "relatively mild infections."

These are serious words in an already heated debate over the legalization of raw milk. I talked to Sally Fallon Morell, the founder of the Weston A Price Foundation (one of the top advocators for clean raw milk), who shared the following thoughts with me:

1. The CDC's estimate that only 1 percent of the dairy products in this country are consumed raw is surprising given the 2007 survey that showed that 3 percent of the population had consumed raw milk within the last seven days. And note that the 2007 survey only asked about raw milk consumption, rather than all raw dairy consumption.
2. Lumping all raw dairy products together is very misleading because of the high rate of severe illnesses from raw queso fresco, which is often made illegally. Most states that allow for legal sales of raw milk do not allow for the sale of raw queso fresco. So illnesses from raw queso fresco in those states cannot properly be attributed to the legality of raw milk. On the other hand, aged raw milk cheese is legal in every state, so any illnesses attributed to aged raw milk cheeses cannot be correlated with the legal status of raw milk.
3. The study appears to overlook a basic sociological issue: in states where raw milk is legal, people are more likely to tell the doctors that they have drunk it. So, regardless of actual risk, it's hardly surprising that there are more illnesses attributed to raw dairy in states where it is legal.
4. Based on the press release, the study authors also did not consider the issue of the differences among states, such as population and the efficiency of the health departments. For example, raw milk is legal is many states that have large populations, which would create an automatic tendency for there to be larger number of outbreaks and illnesses in those states. Similarly, it is well understood in the public health community that some states are much more likely to trace and report foodborne illnesses than others.
5. That's why my fact sheet focused on the 10 states where we have data on consumption rates from the CDC's survey, and compared the number of illnesses from raw milk to the total number of foodborne illnesses in each state."

In a news release, the foundation says the CDC study is flawed. In short, the group feels that statistics were "cherry picked," the dangers of pasteurized milk were ignored, and that statically, raw milk is shown to be safe. Here's a few graphs from the release:

"According the Weston A. Price Foundation, the CDC has manipulated and cherry picked this data to make raw milk look dangerous and to dismiss the same dangers associated with pasteurized milk."

“What consumers need to realize, first of all,” said Sally Fallon Morell, president of the Weston A. Price Foundation, “is that the incidence of foodborne illnesses from dairy products, whether pasteurized or not, is extremely low. For the 14-year period that the authors examined, there was an average of 315 illnesses a year from all dairy products for which the pasteurization status was known. Of those, there was an average of 112 illnesses each year attributed to all raw dairy products and 203 associated with pasteurized dairy products. In comparison, there are almost 24,000 foodborne illnesses reported each year on average. Whether pasteurized or not, dairy products are simply not a high-risk product.”

"Because the incidence of illness from dairy products is so low, the authors’ choice of the time period for the study affected the results significantly, yet their decision to stop the analysis with the year 2006 was not explained. The CDC’s data shows that there were significant outbreaks of foodborne illness linked to pasteurized dairy products the very next year, in 2007: 135 people became ill from pasteurized cheese contaminated with e. coli, and three people died from pasteurized milk contaminated with listeria. (See the foodborne outbreak database here.)"

"Outbreaks from pasteurized dairy were also a significant problem in the 1980s. In 1985, there were more than 16,000 confirmed cases of Salmonella infection that were traced back to pasteurized milk from a single dairy. Surveys estimated that the actual number of people who became ill in that outbreak were over 168,000, 'making this the largest outbreak of salmonellosis ever identified in the United States' at that time, according to an article in the Journal of the American Medical Association."