The detection of bird flu virus particles in the commercial milk supply has rekindled public concern over the long-standing debate on milk pasteurization.
Raw milk sales, which refer to milk that has not been heat-treated to eliminate harmful bacteria, have surged recently after the Department of Agriculture reported in March that dairy cattle herds were affected by highly pathogenic avian influenza.
As per the market research firm NIQ, weekly sales of raw cow’s milk have jumped by 21% since March 25 and 65% compared to the same period last year.
Pasteurization, developed by French scientist Louis Pasteur in the 1860s, involves heating liquids, including milk, to kill harmful bacteria like E. coli, camplyobacter, and salmonella. The United States mandated pasteurization laws in 1924, thus establishing it as a century-old standard in the milk industry.
However, in recent years, there has been growing skepticism about pasteurization, as noted by leaders in the raw milk industry. This skepticism has been compounded by doubts about public health agencies promoting the process, especially since the onset of the COVID-19 pandemic and, more recently, the bird flu outbreak.
“COVID was the best thing that ever happened to raw milk,” Mark McAffee, president of the Raw Milk Institute in California, commented. California is among the 14 states where raw milk sales in grocery stores are permitted and the 21 states where it can be sold directly by farmers.
McAffee, who has almost 25 years of experience in raw milk farming since taking over his family’s farm in the 1990s, believes that it is possible to produce safe raw milk by rigorous testing before shipping and maintaining proper handling practices like rapid chilling to create a desirable product.
Is avian flu in raw milk?
The Food and Drug Administration (FDA) has asserted that pasteurization plays a key role in preventing bird flu from contaminating the commercial milk supply, supported by the disposal of milk from sick cows.
“The pasteurization process has served public health well for more than 100 years,” the FDA stated in its press release on May 10. “Even if the virus is detected in raw milk, pasteurization generally eliminates pathogens to a level that is safe for consumer health.”
As of May 10, the FDA continues to test raw milk samples to determine the level of virus shedding by infected cows. Despite ongoing tests, both the FDA and the Centers for Disease Control and Prevention (CDC) strongly discourage the consumption of raw milk products.
Anna Catharina Berge, a Swedish veterinarian and epidemiologist specializing in raw milk production, explained that the risk of transmitting bird flu to humans through milk is low because avian flu viruses typically spread through close contact and respiratory droplets, not food.
“In the case of avian influenza, these viruses have never been linked to oral infections. Their transmission is always respiratory or through direct contact,” Berge stated. “There has never been a recorded risk of transmission through food for any types of avian influenza identified.”
Kerry Kaylegian, an associate research professor in the Food Science Department at Penn State University, mentioned that her work involves educating Pennsylvania farmers about the dangers of selling raw milk, even though it is legal in the state. She emphasized that while we still have much to learn about the virus, raw milk consumption remains risky.
“We do not fully understand if people can get infected through milk. Much of the concern around bird flu is precautionary, but raw milk always carries the risk of other pathogens,” she noted.
According to the FDA, milk was responsible for 25% of all disease outbreaks due to contaminated food and water in 1938. Today, milk and fluid milk products account for less than 1% of such outbreaks.
Conditions on the farm
Even before the bird flu scare, much of the raw milk debate centered around the cleanliness of dairy farms, with advocates highlighting the strict standards for safe conditions required by law throughout the production process.
McAffee argued that pasteurization disincentivizes industrial farmers from keeping bacteria and viruses out of raw milk, as they rely on the heating process to eliminate these threats. He pointed to economic factors as the reason why.
“Industrial farmers are paid so little for their milk that standards under the Pasteurized Milk Ordinance and FDA regulations allow anything to get in, knowing it will be pasteurized,” McAffee said. “Raw milk farms, on the other hand, must ensure pathogen-free, clean, healthy cows, monitoring everything, and as a result, they get paid ten times more for their milk.”
When asked about the potential drawbacks of pasteurization, Kaylegian stated her experience does not support McAffee’s claims, noting that some dairy producers pay premiums for higher-quality milk regardless of pasteurization.
“Every farmer should want to treat their animals humanely and maintain clean barns,” Kaylegian said. “Healthy animals produce the cleanest and highest quality milk.”
Skepticism of the American regulatory agencies
Berge and her European colleagues have conducted studies finding several benefits to raw milk consumption, such as reduced allergies, asthma, eczema, and respiratory infections.
Raw milk advocates argue that pasteurization alters the whey protein content of milk, but the FDA maintains that the heating process has only limited effects on these properties.
When questioned about why European scientists and regulatory agencies are more open to debating raw milk than their U.S. counterparts, Berge attributed it to differences in food culture.
“Europe has a diverse and historical food culture, and preserving this heritage is important. Governments cannot strip away our cultural identity by enforcing sterile food consumption,” Berge said.
Berge further claimed that U.S. regulatory agencies “are influenced by Big Pharma and food industries,” making them more susceptible to industry pressure than those in other countries.
“The dairy industry realized that pasteurizing milk makes it easier to transport, handle, sell, and maintain a longer shelf-life,” Berge noted. “Therefore, they have no interest in supporting studies that show pasteurized milk can cause allergies and that raw milk can be produced safely.”
In Europe, citizens generally trust government agencies more, whereas there “is a lot more distrust” in the U.S., according to Berge.
