A recent question I received in the office provided me with fodder for this article. A local resident asked: “Are unpasteurized dairy products safe to consume? And, should there be health concerns for those who consume them?”
Since it’s been a few decades since I took a microbiology course, I did a little research before answering these questions to make sure I had the science correct. There’s also a little bit of food history involved.
Back when families used their own cows for milk production, it was consumed fresh out of the cow, rarely requiring storage. As the industrial revolution evolved and more people moved to cities and away from family farming, storage and transportation of milk products prolonged the time between milking and consumption. Without adequate refrigeration and other controls, diseases like tuberculosis, diphtheria, scarlet fever and brucellosis sickened and killed many people.
Louis Pasteur, a French chemist working in the 1860s, recognized that bacteria were causing these diseases. He found that heating the milk for a short time could kill the bacteria, making it safer to drink and extending its shelf-life. Over time, different scientists researched various pasteurization processes that would maintain palatability, make the milk safe to drink, and maintain high nutritional content. It wasn’t until 1947 that states began enacting mandatory dairy pasteurization and, in 1973, the federal government started requiring that any milk used in interstate commerce be pasteurized.
The U.S. Centers for Disease Control and Prevention states that improperly handled raw milk is responsible for about three times more hospitalizations than any other food-borne disease. Between 1998 and 2011, 148 outbreaks of raw milk-related food-borne illnesses affecting 2,394 people, with 284 hospitalizations and two deaths, were reported.
Pennsylvania is just one of 10 states that allows farms to sell raw milk to consumers. A 16-page guidance document available on the Pennsylvania Department of Agriculture website explains the process for farms to achieve and maintain a raw milk permit. Permits are good for one year. To have a permit issued the first time, the farm must be inspected by a department of agriculture official as well as have veterinarian certification confirming that the raw milk-producing herd is free from communicable diseases such as brucellosis and tuberculosis.
The farm water supply must also be tested for bacteriological safety.
A third requirement is that three separate milk samples be tested by a state-approved dairy laboratory and meet or exceed six criteria. Once a farm is approved to sell raw milk, it must continue with annual animal and water tests and also submit lab samples at least twice a month to assure ongoing product safety.
So, yes, raw milk products can be safe to consume if all safety measures are followed from farm to table.
As the consumer, it is important to maintain the milk at 40 F or lower to prevent harmful bacterial growth. Time and temperature are key factors in bacterial growth. If you plan to purchase dairy products — consider how you will keep the product below 40 F from the point of purchase to arriving home. You might keep a cooler in your car with a few cold packs. Avoid storing milk in the refrigerator door where the temperature can vary. Also, rather than purchasing raw milk in gallon containers, consider purchasing it in smaller amounts to ensure that you consume it before it spoils. If possible, purchase it directly from the farm where it is likely fresher than it would be from an off-farm point of purchase, where maintenance of time and temperature may have lapsed.
Regarding health concerns for people consuming raw milk products, there can be challenges especially for folks who are immunocompromised —young children who don’t have a fully developed immune system, elderly people and those dealing with some chronic illnesses.
In addition to brucellosis and tuberculosis, other raw milk-associated diseases include campylobacter and listeriosis. Also, on occasion the routine testing of raw milk may reveal that the product is contaminated. If contamination is found or if people report illnesses, then the public is notified and the farm must follow certain procedures to resume production.
In summary, consumption of raw milk is not without its cautions. Your risk of obtaining a food-borne illness from consuming raw milk products is reduced if food safety procedures are followed from farm to table and you have a healthy immune system.
Robin Kuleck is a Penn State Extension senior educator in food, family and health, based in Cameron County.