Pasteurized milk has been heated to kill bacteria that can cause severe illness. (Photo by John Wozniak, LSU AgCenter)

News Release Distributed 05/12/15

BATON ROUGE, La. – Unpasteurized raw milk can harbor several bacteria that can cause severe illness, particularly in young children, the elderly and immune-compromised individuals, said an LSU AgCenter food safety specialist.

Consuming unpasteurized milk creates a greater likelihood of illness, said Wenqing Xu.

Unpasteurized milk has a greater chance to harbor food-borne pathogens, Xu said. These can include campylobacter, listeria, salmonella and E. coli I57:H7 – all of which can cause illness.

“Contamination of raw milk can occur from a variety of microorganisms from a variety of sources,” she said. The risk can occur at any stage of handling.

Illness from any of these pathogens takes a certain dose-response level – the amount of the pathogen required to cause symptoms, said LSU AgCenter dairy science professor Bruce Jenny.

“Unpasteurized milk has a high risk,” Xu said. “Symptoms may vary and may include diarrhea, vomiting and fever. In addition, listeria can cause miscarriage in pregnant women.”

Symptoms can range from minor to severe, depending on the individual and the level of the pathogen present, Jenny said.

Besides milk itself, products made from contaminated milk, such as cheeses and butter, are still unhealthy. “Contamination won’t disappear,” Xu said.

“Our concern is people think raw milk is better, healthier,” she said. But the data show no significant difference in health benefits.

“Unpasteurized milk is not a safe product,” Jenny said. “It has inherent hazards.”