Since posting the 2010 list of raw (unpasteurized) dairy-related problems, I’ve been asked about pasteurized dairy products. In a previous review, outbreaks from pasteurized milk products were found to be very uncommon considering the large number of people who drink them.

Statistics from the CDC and State Health Departments comparing raw and pasteurized dairy products linked to reported foodborne disease outbreaks (1973-2006) show that raw milk and Mexican-style queso fresco soft cheeses (usually made from raw milk) caused almost 70% of the reported outbreaks even though only 1-3% of the population consumes raw dairy products. If raw and pasteurized milk were equally risky, it would be expected that there would be far more pasteurized outbreaks since the number of people drinking conventional milk is so much higher.

Yet, pasteurized milk can carry the same pathogens as raw dairy products if 1) they are inadequately pasteurized (failure of process) or 2) contaminated after processing. Although uncommon, pasteurized milk is not immune to problems, and has been the source of serious illnesses and death. In 2007, three men in Massachusetts died after drinking pasteurized milk distributed from a local dairy. The milk was contaminated with Listeria in the bottling area of the facility in which it was produced.

So, what about the safety of pasteurized milk in 2010? No pasteurized fluid milk outbreaks have been reported to my knowledge this year. In contrast, we continue to see problems with Mexican-style cheeses (e.g., Queso fresco), including those made with pasteurized milk. Mexican-style cheese produced illegally using raw milk is sometimes called “bathtub cheese” because of the unsanitary conditions found in their production. Investigators have literally found these illegal cheeses produced in home bathtubs.

However, legal, retail Mexican-style soft cheeses should be safe. Or, not?

Food safety experts recommend that susceptible persons including pregnant women, the elderly, and immunocompromised persons avoid soft cheeses because of the risk of listeriosis. Despite efforts to prevent contamination, soft cheeses, including Mexican-style soft cheeses, are vulnerable to post-pasteurization contamination with Listeria monocytogenes.

2010 recalls and illnesses due to Mexican-style soft cheeses made with pasteurized milk:

Queseria Bendita Recalls Queso Fresco, Panela, and Requeson Because of Possible Health Risk
Yakima, WA
February 2010 (Possible link to human illness)

Del Bueno Amends Recall of Queso Fresco Cheese Because of Possible Health Risk
Grand View, WA
April 2010

Azteca Linda Corp. Recalls QUESO FRESCO and QUESO HEBRA Because of Possible Risk of Health
Brooklyn, NY
July 2010

  • Doc Mudd

    Thank you, Mr. Marler, for following up on this line of questioning from a few commenters on earlier posts who defended their pro-raw milk stance and attempted to deflect the issue by questioning the safety of pasteurized milk.
    Those questioners failed to produce any statistics themselves at the time, and now we know why – there is no similarity in risk between pasteurized and unpasteurized milk. They were only speculating and running a desperate bluff.
    Thank you for doing the homework on this and clearing away yet another smoke screen emitted by diehard proponents of raw milk.

  • Greg

    Interesting. The evidence begins to mount. So raw is many times more dangerous than pasteurized.
    The only question in my mind (after a heap of reading) is: Is it VERY dangerous? Or is many times more dangerous still “not very dangerous”?
    In other words, how many illnesses can be expected per 1000 serves of raw milk, versus, say, 1000 serves of mayonaise?
    In my research I’m finding the anti-raw side to be much better referenced, as well as getting the facts straight, and addressing the rebukes of the other side. Most importantly I’d point to:
    “Testimony of John F. Sheehan, B.Sc. (Dy.), J.D., Director, Division of Plant and Dairy Food Safety Office of Food Safety Center for Food Safety and Applied Nutrition U.S. Food and Drug Administration before the Health and Government Operations Committee Maryland House of Delegates March 15, 2007”

  • Jennifer

    Actually, the recent conversation about pasteurization and listeria is that dairies who are following proper procedures of pasteurization are experiencing listeria outbreaks. (Germany being one recent occurance.) The same points you made for pasteurized milk can be applied to the handling of raw milk.
    The CDC is questioning the need for higher heat as listerie seems to be resisting the heat being used.