Raw Milk and Pasteurization

The case for raw milk, a term used for unpasteurized and unprocessed animal milk, is one of the most controversial issues in food marketing today. Nearly all milk available in grocery stores in the United States is pasteurized and homogenized cow’s milk. Through the application of heat, pasteurization kills bacteria and any disease-causing pathogens that may be present in milk. Pasteurization and homogenization change the smell, taste, “mouth feel,” and nutritional content of milk; the extent of these changes constitutes the basis of a continuing debate among food activists and consumers. Proponents of raw milk say that commercial milk is technically “denatured,” and only raw milk can be considered “real milk.” Defenders of pasteurization argue that the process ensures safe milk for consumers and is the only practical way of delivering sufficient quantities to buyers located far from farm sources. Current debate has resulted in exaggerated claims on both sides, yet it has also generated important clarification of issues in the larger struggle for “food rights” (the controversy over who determines the food supply available to consumers). On a more specific level, the debate focuses on safety issues, comparative nutritional content, and the nature and quality of commercial milk in general—all of which are discussed in this entry.

The components of milk—carbohydrates, fats, and proteins—provide an ideal site for the growth of bacteria and harmful pathogens. These include [Page 1179]enterotoxigenic Staphylococcus aureus, Campylobacter jejuni, Salmonella, Escherichia coli, Listeria monocytogenes, Mycobacterium tuberculosis, Mycobacterium bovis, Brucella, Coxiella Burnetii, and Yersinia enterocolitica. Many infections caused by contaminated milk can lead to lasting health problems and sometimes death, especially in infants, the elderly, and people with compromised immune systems. Pathogens may reside in the intestines of herd animals and, thus, through excretion, may contaminate the environment in which animals live. During the era of pasteurization legislation, spanning the first two decades of the 20th century, herds were likely to include cows suffering from tuberculosis and brucellosis; today, herds are regularly vaccinated and tested for disease. Proximity to fecal matter has always posed a hazard to milk collection, and most farmers now observe scrupulous practices, including careful efforts to clean udders and teats during the milking process. Yet contamination can occur anywhere along the pipeline of production, introduced by humans, insects, and rodents, and may enter through equipment and containers used for shipping milk. Transport and storage of milk present special challenges and dangers, and the contemporary demand for purity and freshness places a significant burden on producers, middlemen (meaning processing plants that collect supplies from numerous farmers), and marketers.

However, pasteurization does not guarantee that milk supplies will remain uncontaminated. A 2007 incident in Massachusetts, where a bottling facility transmitted Listeria, resulted in the deaths of three men. Norovirus presents a common threat passed on to consumers through the milk supply, owing to poor hygiene habits of those who work along the supply chain. Yet considering how much milk is consumed today, relatively few cases of illness traced to commercially marketed milk supplies are reported each year.

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