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Raw milk may transmit bird flu virus

Recent research reveals a concerning connection between raw milk and the H5N1 avian influenza virus, commonly known as bird flu

This discovery raises significant questions about the safety of consuming raw milk, particularly during periods of heightened avian influenza outbreaks.

Flu virus in raw milk

In a recent study, scientists investigated the impact of H5N1-contaminated raw milk on mice. The results were alarming, with mice exhibiting signs of illness shortly after consumption. 

High levels of the virus were detected in their respiratory organs and other parts of their bodies – even in the mammary glands of female mice not actively lactating.

“Our data indicate that HPAI A[H5N1] virus in untreated milk can infect susceptible animals that consume it,” concluded a team led by virologist Yoshihiro Kawaoka of the University of Wisconsin–Madison.

These findings suggest that consuming raw milk contaminated with H5N1 could lead to infection in mammals, including humans. While the risk of transmission to humans remains low, the potential consequences are severe enough to warrant caution.

Killing the flu virus in raw milk

Fortunately, pasteurization – a process involving heating milk to high temperatures – effectively eliminates the H5N1 virus. This makes pasteurized milk safe for consumption, even during avian influenza outbreaks.

The study also revealed that refrigeration alone does not guarantee the elimination of the virus. In fact, the virus levels in refrigerated, contaminated milk declined slowly over five weeks, indicating a prolonged period of potential infectivity.

The researchers explored the effects of pasteurization by heating the infected milk and found that virus levels were significantly reduced, although not always entirely eliminated. 

While the study’s conditions did not precisely replicate industrial pasteurization processes, the results underscore the critical role of pasteurization in ensuring milk safety.

Broader risks of raw milk

The H5N1 virus is not the only concern associated with raw milk. According to data from the U.S. Centers for Disease Control and Prevention (CDC), raw milk has a history of causing significant health issues.

Between 1998 and 2018, raw milk consumption led to over 2,600 illnesses, 228 hospitalizations, and three deaths. These incidents were linked to various pathogens commonly found in unpasteurized dairy products, such as Salmonella, E. coli, and Listeria.

This extensive record of health problems underscores the broader risks of consuming raw milk. Unlike pasteurized milk, which undergoes heat treatment to kill harmful bacteria, raw milk can harbor dangerous microorganisms that pose serious health threats.

The evidence from the CDC highlights the importance of choosing pasteurized milk to prevent these risks and ensure safer consumption of dairy products. This awareness is crucial for protecting public health and preventing future outbreaks.

Misconceptions about raw milk

Many raw milk enthusiasts tout its supposed superior nutritional benefits and claim it can alleviate lactose intolerance and allergies. However, these assertions lack strong scientific support.

Nutritional comparison

The nutritional differences between raw and pasteurized milk are minimal. Both contain essential nutrients such as calcium, protein, and vitamins B and D.

Pasteurization slightly reduces some heat-sensitive vitamins, like vitamin C, but milk is not a major source of these nutrients. The process primarily aims to eliminate harmful pathogens and viruses without significantly altering the nutritional content of raw milk.

Lactose intolerance and allergies

Advocates often claim that raw milk can help with lactose intolerance and allergies. The idea is that raw milk contains natural enzymes that aid in digestion and reduce allergic reactions. However, scientific studies do not support these claims.

Lactose intolerance results from the body’s inability to produce lactase, the enzyme needed to digest lactose, which pasteurization does not affect. Similarly, milk allergies are reactions to proteins in milk, which remain unchanged regardless of pasteurization.

Recommendations and precautions

“Don’t drink raw milk – that’s the message,” said Kawaoka. Given the potential dangers, health experts strongly advise against consuming raw milk, especially during avian influenza outbreaks. Opting for pasteurized milk significantly reduces the risk of exposure to harmful pathogens, including the H5N1 virus.

The recent findings serve as a reminder of the importance of pasteurization in ensuring the safety of our food supply. While raw milk may have its proponents, the potential risks outweigh any perceived benefits.

In conclusion, the presence of the H5N1 virus in unpasteurized milk underscores the importance of adhering to safe food practices. Choosing pasteurized milk is a simple yet effective way to protect yourself and your loved ones from potential harm. 

As always, it’s crucial to stay informed about food safety guidelines and make informed decisions about the products you consume.

The study is published in the journal New England Journal of Medicine.


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