Is Raw Milk Safe to Drink?

While proponents say raw milk offers health advantages, scientists and medical professionals cite clear concerns about safety. When deciding whether to stick with conventional pasteurized milk or try raw milk, it’s important to understand the facts.

“Raw milk can contain harmful bacteria that can cause serious illnesses, which have been successfully avoided by pasteurization for over a century,” says Columbia clinical microbiologist Gregory Berry, PhD. He believes that the pros of raw milk do not outweigh the risks, and explains why.

What is raw milk, and how is it different from pasteurized milk?

Raw milk comes directly from animals, such as cows, goats, and sheep. It has not been treated to kill bacteria, viruses, or other pathogens.

Pasteurized milk, on the other hand, is heated to a specific temperature for a set period of time to kill harmful pathogens. Pasteurizing milk is a standard practice to ensure safety before milk is sold and consumed. This practice dates back to the mid-19th century and was first described by the French microbiologist Louis Pasteur.

What are some of the illnesses from the bacteria in raw milk that people can get?

Raw milk can contain harmful bacteria, including Salmonella, E. coli, Listeria, Campylobacter, Brucella, Coxiella burnetii (Q Fever), and even Tuberculosis. These can cause serious illnesses and lead to a host of different symptoms ranging from cough and fever to internal organ damage and, although rarely, even death.

Who is most at risk of illness?

People who are most vulnerable to these pathogens include children, especially those under age five, pregnant women, elderly individuals, and people with compromised immune systems.

Could raw milk be infected with the H5N1 (bird flu) virus? And if so, can people get bird flu by drinking raw milk?

Yes, the H5N1 avian influenza virus has been found in cow’s milk. Pasteurizing milk kills the virus, but raw milk can contain high levels of infectious H5N1 virus, and it would be unsafe to drink from an infected cow since there is a clear risk of infection.

Even though the CDC says raw milk can be a source of foodborne illness, some say that raw milk has its advantages. What are those perceived benefits?

Raw milk advocates often cite potential health benefits, such as better taste, more nutrients and vitamins (which is controversial), and potentially beneficial enzymes and probiotics. All that being said, the scientific and medical consensus is that these benefits do not outweigh the safety concerns. Pasteurization has a minimal effect on the overall nutrition found in milk.

Is it medically accurate to say that raw milk has beneficial enzymes and more diverse probiotics?

Raw milk does contain certain enzymes, such as lipase and lactase, that can break down fats and lactose, but the human body also produces its own enzymes to process these components in milk.

As far as probiotics, raw milk does contain live bacteria, which include some bacteria that could be considered probiotics. However, probiotics in raw milk can vary widely depending on factors like the cow’s diet, as well as milk handling and storage conditions. In fact, Bifidobacteria, one of the purported types of probiotics in raw milk, is actually an organism found in the GI tract of cows, which means its presence would suggest fecal contamination of the milk.

Has raw milk been associated with lower rates of asthma and allergies?

Results of studies linking raw milk to fewer cases of asthma and allergies have been inconclusive. There is no strong medical evidence that raw milk directly prevents or alleviates asthma or allergies.

Overall, do the benefits of raw milk outweigh the risks?

The scientific consensus, especially from organizations like the Centers for Disease Control, the Food and Drug Administration, and the World Health Organization, is that the infection risk of raw milk outweighs any potential health benefits.

While raw milk proponents argue for its superior taste, nutritional value, and health benefits, these claims are not robustly supported by scientific evidence. Pasteurization has very little downside, and medical experts consider it to be a much safer option.

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Gregory Berry, PhD, is an associate professor of Pathology and Cell Biology and co-director of the Clinical Microbiology Service and the Center for Advanced Laboratory Medicine at Columbia University’s Vagelos College of Physicians and Surgeons.