The consumption of raw milk is growing in popularity.  Raw milk is milk that has not been pasteurized.  Consumers looking for a healthier lifestyle may make the decision to drink raw milk because they believe that it is more nutritious or that it can solve or prevent health problems.  They may not realize that instead of improving health, they may be putting themselves at risk. 

Raw milk contains bacteria that can cause sickness and death.  Bacterial contamination can occur even when good hygienic practices are in place.  Common sources of contamination include:

• Cow feces coming into contact with the milk
• Infection of the cow’s udder (mastitis)
• Cow diseases (bovine tuberculosis)
• Bacteria on the cow’s skin or in the environment (dirt, processing equipment)
• Insects, rodents, animal vectors
• Humans (1)

The number of outbreaks in the United States caused by unpasteurized milk has increased in recent years.  From 2007-2012, 81 outbreaks were reported to the Centers for Disease Control and Prevention (CDC), resulting in 979 illnesses and 73 hospitalizations.  Between 2007-2009, 30 outbreaks were linked to raw milk.  This increased to 51 outbreaks from 2010-2012 (3).

• The CDC reported that unpasteurized milk is 150 times more likely to cause foodborne illness than pasteurized milk (2).
• The most common bacterial cause of outbreaks was Campylobacter (81%) followed by coli (17%) and Salmonella (3%).
• Those with the highest risk of getting sick from drinking raw milk were young children, the elderly, and people with weakened immune systems (3).

Many misconceptions and unsupported claims exist concerning the benefits of raw milk versus pasteurized milk.  Some of the more common myths are:

• MYTH: Raw milk contains natural antimicrobial components that make it safe.
• FACT: Naturally occurring antimicrobial compounds do exist in milk, but their concentration is not high enough to ensure the safety of raw milk (4,5).

• MYTH: Pasteurization reduces the nutritional value of milk.
• FACT: Pasteurization does not significantly change the nutritional value of milk.  Vitamins that are found in milk at high levels, such as riboflavin, B6 and B12, are relatively heat stable.  The only vitamin that is significantly reduced by heat is Vitamin C, but milk is not a major source of vitamin C (4).  Pasteurization does not change protein quality.  Minor levels of whey denaturation have been reported, but protein denaturation does not affect the nutritional quality of protein.  Minerals are heat stable and not affected by pasteurization (5).

• MYTH: Raw milk can cure lactose intolerance.
• FACT: People who are lactose intolerant lack the lactase enzyme necessary for breaking down lactose during digestion.  All milk, raw or pasteurized, contains lactose.  Lactase does not naturally occur in milk (4).   A 2014 randomized controlled study found that raw milk did not reduce lactose malabsorption or lactose intolerance symptoms compared with pasteurized milk among adults positive for lactose malabsorption (6).

• MYTH: Raw milk can cure or treat asthma and allergy.
• FACT: A 2007 study often cited by raw milk advocates found an inverse association of farm milk (not raw milk) with asthma and allergy.  Many farm residents boil their milk prior to consumption, and the authors had no objective confirmation that the farm milk samples were raw.  The study concluded that consumption of raw farm milk cannot be recommended as a preventive measure (7).

Consumers seeking health benefits can safely enjoy pasteurized milk and milk products.  Pasteurization effectively destroys pathogens found in raw milk without significantly changing its nutritional value. 

To learn more, please contact a Registered Dietitian Nutritionist on the Idaho Academy of Nutrition and Dietetics website by clicking Find a RD.

Written by Idaho State University Dietetic Student,

Lori Friedman

References:

1. Centers for Disease Control and Prevention. (n.d.). Raw milk questions and answers. Retrieved March 18, 2016, from http://www.cdc.gov/foodsafety/rawmilk-questions-and-answers

2. U.S Food and Drug Administration. (n.d.). The dangers of raw milk: Unpasteurized milk can pose a serious health risk. Retrieved March 18, 2016, from http://www.fda.gov/Food/ResourcesForYou/Consumers/ucm079516.htm

3. Centers for Disease Control and Prevention. (2016, March 16). Increase in outbreaks associated with nonpasteurized milk, United States, 2007-2012. Retrieved March 18, 2016, from http://www.cdc.gov/foodsafety/rawmilk/nonpasteurized-outbreaks-2012.html

4. U.S Food and Drug Administration. (2011, November 1). Raw milk misconceptions and the danger of raw milk consumption. Retrieved March 18, 2016, from http://www.fda.gov/Food/FoodborneIllnessContaminants/BuyStoreServeSafeFood/ucm277854.htm

5. Lucey, J. A. (2015). Raw milk consumption. Nutrition Today, 50(4), 189-193. doi:10.1097/nt.0000000000000108

6. Mummah, S., Oelrich, B., Hope, J., Vu, Q., & Gardner, C. D. (2014). Effect of raw milk on lactose intolerance: A randomized controlled pilot study. The Annals of Family Medicine, 12(2), 134-141. doi:10.1370/afm.1618

7. Waser, M., Michels, K. B., Bieli, C., Flöistrup, H., Pershagen, G., Mutius, E. V., . . . Braun-Fahrländer, C. (2007). Inverse association of farm milk consumption with asthma and allergy in rural and suburban populations across Europe. Clinical & Experimental Allergy Clin Exp Allergy, 37(5), 661-670. doi:10.1111/j.1365-2222.2006.02640.x