Ynte Schukken, professor of epidemiology and herd health at Cornell's College of Veterinary Medicine in Ithaca, N.Y., and co-author Alejandra Latorre, a graduate student, produced a comprehensive map showing which populations were most at risk when buying from various sources.
The researchers analyzed risk across various purchasing methods including buying from a farm's on-site store, directly from its bulk tank or from a third-party retailer.
"Raw milk from retailers proved most dangerous by far. But when it comes to milk, the safest purchasing decision you can make is to buy it pasteurized," Schukken said in a statement.
"Listeria is one of the most virulent and deadly food borne pathogens. Our study demonstrates the relative risk various populations face when ingesting raw milk, including farm workers, pregnant women, young babies and the elderly. Compared to intermediate-aged adults, these last three groups were particularly susceptible."
Despite its dangers, 28 states permit the sale of raw milk. Raw milk enthusiasts claim health benefits from nutritious compounds supposedly destroyed by pasteurization, Schukken explained.
"These claims are not backed by scientific evidence, and several studies have shown them to be myths," Schukken said. "Pasteurization helped revolutionize health, effectively ending diseases such as tuberculosis and Q fever. Bypassing this safety measure could have serious consequences for public health, dramatically increasing bacterial infection and outbreaks."
The findings were published in the Journal of Food Production.