What you need to know 

• Raw milk, also known as unpasteurized milk, is animal milk that has not gone through pasteurization—the heating process that kills harmful bacteria and other germs. 
• Consuming raw milk and its products can expose you to dangerous germs that can cause food poisoning, severe illness, and even death. 
• Children under 5 years, adults over 65, pregnant people, and people with weakened immune systems are most at risk for harmful effects from consuming raw milk. 

On February 3, New Mexico health officials warned against consuming raw milk products following the death of a newborn from Listeria infection. Authorities said the baby’s infection was likely linked to the mother’s consumption of raw milk during pregnancy. 

Then on March 15, the Food and Drug Administration announced it was investigating a multistate outbreak of E. coli infection in California, Florida, and Texas, linked to raw cheddar cheese from the Raw Farm brand. As of April 3, the FDA and the Centers for Disease Control and Prevention have reported nine cases of illness, more than half of them in children under 5 years. Three people were hospitalized, and one developed hemolytic uremic syndrome, a condition that can cause life-threatening kidney failure.

Raw milk can carry dangerous germs that may lead to severe illnesses and even death. Studies have linked the increased sale of raw milk products to an increase in disease outbreaks. Despite these risks, raw milk consumption has grown in popularity in the U.S., promoted by influencers and high-profile politicians.

Read on to learn what raw milk is, its risks, and why pasteurization matters. 

What is raw milk?

Raw milk is animal milk that has not gone through pasteurization—the process that kills harmful bacteria, viruses (like bird flu), and other germs. Developed by Louis Pasteur in the 1860s, pasteurization involves heating milk to a very high temperature to kill harmful germs without significantly affecting its nutritional value.

Raw milk isn’t just consumed on its own. It’s also used to make a range of dairy products, including certain cheeses (like queso fresco), yogurt, and butter. In some cases—especially with fresh, soft cheeses—people may not realize a product was made with unpasteurized milk.

What happens if you consume raw milk or raw milk products?

Because raw milk is not pasteurized, it can contain harmful bacteria such as Brucella, Campylobacter, E. coli, Listeria, and Salmonella. These can cause food poisoning and severe illness. 

According to the American Medical Association, common symptoms include diarrhea, vomiting, and stomach cramps. The CDC notes that infections can also lead to severe conditions such as Guillain-Barré and hemolytic uremic syndrome, which can result in stroke, paralysis, kidney failure, or death.

Those most at risk include: 

• Children under 5 years
• Adults over 65 
• Pregnant people 
• People with weakened immune systems 

“If you look at the statistics for outbreaks for people consuming raw dairy, whether it’s milk or cheese…a very high percentage of the people who get very sick and hospitalized tend to be children,” John Lucey, professor of food science and director of the Center for Dairy Research at the University of Wisconsin-Madison, tells Public Good News.

He adds that infections like Listeria can be especially serious for pregnant people, potentially leading to stillbirth or infant loss.

Raw milk may also affect how your body responds to antibiotics. “A lot of raw milk contains high levels of antibiotic-resistant bacteria because a lot of the cows are pumped with antibiotics,” Dr. Supriya Rao, a gastroenterologist, partner at Integrated Gastroenterology Consultants, and assistant professor at Tufts University School of Medicine, explains. “So bacteria is making it through. They’re already a highly resistant strain, and so that can lead to infections, and if you have an infection, it’s very difficult to treat if you’re already limited [in] the types of antibiotics you can use.”

Why is pasteurization so important?

Milk can be exposed to bacteria from soil, feed, manure, and infections in cows, such as mastitis. Even with careful farming practices, contamination risks remain.

“The farm has places that contain pathogens, that’s their environment, and so the farmer is always trying to reduce the risk of contamination by keeping the animals as healthy as possible,” Lucey adds. “It’s just a constant; they have to be very vigilant, but that means that it’s not foolproof.”

Pasteurization, which has been studied for over 150 years, Lucey adds, makes milk safer to consume by killing harmful pathogens. “This process is an important safeguard for the milk,” he says. “In raw milk production, they don’t have that additional safeguard.” 

“Before pasteurization was introduced in the U.S. and around the world, consumption of milk was a major source of food contamination or foodborne illnesses,” Lucey explains. “Now, if you look at milk and dairy products, less than 1 percent of all the foodborne outbreaks are related to any dairy product, whether it’s raw or pasteurized…That’s an amazing change, [and] that change was due to pasteurization.” 

What about raw milk products like cheese?

Raw milk products, including cheese, also carry risks—as shown by the recent outbreak linked to raw cheddar. Rao notes that while both milk and cheese can be risky, “the milk [has] higher risk because oftentimes pus and blood and other things present in the milk. [Meanwhile,] the cheese gets processed a bit, so the likelihood of it harboring that is less than of milk itself.” 

It also can depend on the type of cheese. The FDA allows raw milk cheeses to be sold if they are aged for at least 60 days, a process intended to reduce bacterial levels. However, this does not guarantee that all pathogens are eliminated. Some cheeses, particularly soft or high-moisture varieties (like cottage and mozzarella), may carry higher risk.

Why are people consuming raw milk?

Some influencers and public figures, including Health and Human Services Secretary Robert F. Kennedy Jr., have promoted raw milk as part of broader “natural health” trends.

Raw milk is often portrayed as more “natural” or less processed than pasteurized milk. Others believe it has added health benefits, such as improving digestion or preventing allergies—claims that circulate widely online but have been consistently debunked. There’s also a growing interest in buying food directly from farms or local producers, which can make raw milk feel like a more wholesome or trustworthy option.

Are there any benefits to drinking raw milk over pasteurized milk?

Public health experts say those perceived benefits aren’t supported by strong scientific evidence. According to the FDA, pasteurization does not significantly change the nutritional value of milk—meaning raw milk doesn’t offer a meaningful nutritional advantage.

What is well established, experts say, is the risk of consuming raw milk products. “The risk of dangerous illness far outweighs any alleged benefit,” says Rao.

For more information, talk to your health care provider.

This article first appeared on Public Good News and is republished here under a Creative Commons Attribution-NoDerivatives 4.0 International License.