Summary
Science Friday host Rachel Feltman interviews infectious disease specialist Dr. Celine Gounder and Cornell dairy microbiologist Dr. Nicole Martin about the risks of drinking raw milk. Dr. Martin explains that pasteurization is a brief 162-degree, 15-second heat treatment that eliminates dangerous pathogens with minimal impact on milk's nutritional profile. She details how pathogens like salmonella, listeria, campylobacter, and E. coli naturally contaminate raw milk from soil, water, manure, and subclinically infected cows. Dr. Gounder discusses the H5N1 bird flu threat in dairy herds and how pasteurization effectively kills the virus. Both experts emphasize that there is no scientific evidence supporting health benefits of raw over pasteurized milk, and that the flavor differences people prefer can be achieved through single-farm pasteurized products.
Key Points
- Pasteurization is 162 degrees Fahrenheit for 15 seconds, with minimal impact on milk's nutritional composition
- Campylobacter is the most common pathogen causing outbreaks from raw milk in the US
- Listeria has a mortality rate of 15-20% and is particularly dangerous for pregnant women, children, and immunocompromised
- Cows can shed bacteria into milk while appearing completely healthy (subclinical disease)
- There is no way to use your senses to determine if harmful bacteria are present in raw milk
- Pasteurization effectively kills H5N1 bird flu virus; fragments of dead virus found in pasteurized retail milk confirm it was present
- Raw milk sales increased 65% year over year according to Nielsen IQ data
- Flavor differences attributed to raw milk can be achieved with single-farm pasteurized products
Key Moments
Pasteurization is 162 degrees for 15 seconds with minimal nutritional impact
Cornell dairy microbiologist Dr. Nicole Martin explains that pasteurization is a very brief heat treatment at 162 degrees Fahrenheit for 15 seconds, with very minimal impact on milk's nutritional constituents. There is no scientific evidence that raw milk is nutritionally superior.
"There's really not. So I hear this a lot from various folks, and there's a lot of belief systems to that idea that raw milk is in some way healthier than, nutritionally healthier than pasteurized milk. But the reality is this is a very mild heat treatment."
Campylobacter, E. coli, and listeria pathogens naturally found in raw milk
Dr. Martin details the range of pathogens naturally found in raw milk, from campylobacter causing gastrointestinal illness to listeria with a 15-20% mortality rate, emphasizing that you cannot visually inspect milk for these dangers.
"Then on the other end of that spectrum, we have a pathogen like listeria, which has a mortality rate of 15 to 20%. So folks who get ill with that pathogen, a lot of them die."
Pasteurization kills H5N1 bird flu in milk
Dr. Gounder explains that pasteurization effectively kills H5N1 bird flu virus in milk, with dead virus fragments found in pasteurized retail milk confirming the virus was present but neutralized by heat treatment.
"People who drink raw milk risk not only getting H5N1 bird flu infection, but also E. coli, salmonella, campylobacter, and listeria bacterial infections."
Flavor differences can be achieved with pasteurized single-farm milk
Dr. Martin explains that the flavor people attribute to raw milk comes from single-farm sourcing and higher fat content, not from skipping pasteurization. You can get the same flavor profile from a pasteurized single-farm product without the disease risk.
"Again, I just want to come back to the idea that if that's the value proposition for a consumer, that they like that unique flavor from a certain farm or they like the higher fat level. You can get all of those things in a pasteurized product and not have the risk of the foodborne disease."
