Despite an ongoing outbreak of bird flu in dairy cows, the popularity of raw milk has only increased. Proponents claim that raw milk has superior health benefits over pasteurized milk. However, there is little evidence to support these claims and the risk of serious illness is much higher.
Mississippi State University food scientists Juan Silva and Joel Komakech and nutritionist Mandy Conrad explain the difference between pasteurized and raw milk, addressing common misconceptions about the health risks and supposed benefits of consuming unpasteurized milk. These questions are more important than ever because cattle can shed viral material in their milk. Not only can pathogens get into milk, but at least three farm workers are reported to have contracted the H5N1 virus, the virus that causes bird flu, in 2024. Farm workers can become ill from handling infected animals or their byproducts, such as raw milk.
What is pasteurization? Does it destroy nutrients?
Pasteurization is a process of heating beverages and foods to high temperatures – more than 145 degrees Fahrenheit (62.78 degrees Celsius) – to kill harmful microorganisms, such as bacteria, viruses and parasites. This reduces the overall number of microorganisms in the product and also inactivates enzymes that can contribute to spoilage.
The taste, nutritional value and quality of pasteurized products are not significantly affected by the process.
Although pasteurization may result in some nutrient loss, the changes are generally minimal and outweigh the benefits. Pasteurization generally causes minor denaturation of proteins and has little effect on fats and carbohydrates. Although water-soluble vitamins such as vitamin C and some B vitamins, which are not usually abundant in milk except vitamin B2, can be partially degraded during pasteurization, fat-soluble vitamins (A, D, E and K, which are amounts found in milk) are more heat stable and suffer minimal loss.
Thus, the nutritional losses in milk due to pasteurization are generally small compared to the significant benefits of reducing foodborne illness and spoilage.
Is raw milk healthier than pasteurized milk?
Studies have compared the benefits of raw milk to pasteurized milk and have found little evidence that raw milk is superior to pasteurized milk. The perceived benefits of raw milk are outweighed by its health risks.
First, raw milk does not improve lactose intolerance.
Raw milk also does not contain more vitamins than pasteurized milk. Milk is not a good source of vitamin C or other heat-sensitive vitamins, and pasteurization does little to reduce vitamin B2 or riboflavin, which is not as sensitive to heat. Additionally, vitamin D is added to pasteurized milk to increase your body’s ability to absorb calcium in milk.
Fortified milk replaces nutrients that can be lost during the pasteurization process. Vitamin D is added to milk to improve the absorption of the calcium in the milk. No food is perfect, so it’s okay for milk to lack certain nutrients as these can be obtained from other foods.
Some people believe that probiotics – foods or supplements that contain live bacteria that are beneficial to health – are more commonly found in unpasteurized milk and products made from raw milk. However, raw milk generally does not contain probiotics and contains significantly more harmful bacteria. Probiotics are added to many dairy products, such as yogurt, after pasteurization.
Furthermore, a 2011 review of the available research on the health benefits of raw milk found that many of these studies were conducted with poor methods, meaning their results should be interpreted with caution.
What are the health risks of consuming raw milk?
The health risks of consuming raw, unpasteurized milk come from the harmful microorganisms that may be present.
Raw milk has been linked to hundreds of outbreaks of foodborne illness. Between 1998 and 2018, 202 outbreaks resulted in 2,645 illnesses and 228 hospitalizations. More recently, from 2022 to 2023, there were 18 outbreaks and recalls linked to raw milk. In 2024, a number of outbreaks and recalls have already occurred related to pathogens in raw milk. In all cases, pathogens in the raw milk that cause human illness were directly responsible for these diseases.
Some diseases caused by the pathogens in raw milk can have serious long-term consequences, including paralysis, kidney failure and death.
Researchers found that areas where raw milk was legally sold in the US between 1998 and 2018 had more than three times as many outbreaks as areas where raw milk sales were illegal. Areas where raw milk was allowed to be sold in stores experienced almost four times more outbreaks than areas where sales were only allowed on farms.
Is it safe to eat food made from raw milk?
Many, if not all, dairy products made from unpasteurized milk are not safe to eat. A number of products can be made from raw milk, including soft cheeses such as brie and camembert; Mexican-style soft cheeses, such as queso fresco, panela, asadero and queso Blanco; yoghurt and puddings; and ice cream or frozen yogurt. Pathogens in raw milk can survive the processes involved in making these types of dairy products and are therefore unsafe for consumption.
Only products that undergo a process to inhibit or kill harmful microorganisms can be safe enough to be made from unpasteurized milk. However, the potential for cross-contamination of raw and cooked food and the survival of pathogens due to inadequate processing are high when products are made with raw milk.
Can Pasteurized Milk Still Make You Sick?
The few reported outbreaks linked to pasteurized milk can be traced to contamination after pasteurization. When handled properly, pasteurized milk is a very safe product.
The US government is requiring farmers to destroy milk from flocks infected with bird flu. Since June 2024, twelve states have reported flocks positive for H1N5, the virus that causes bird flu.
There is currently no evidence that consuming pasteurized milk from infected cows causes disease in humans. Based on the available evidence, the Food and Drug Administration currently states that pasteurization can destroy or inactivate heat-sensitive viruses such as H5N1 in milk.
However, consuming raw milk may pose a risk of transmitting diseases to humans.
Can you get immunity against H5N1 by drinking raw milk?
Some people believe that drinking raw milk can boost their immune system. However, there is no scientific evidence that drinking raw milk can improve immunity against diseases.
Vaccines train your body to protect itself against future infections without actually getting sick from that infection. They do this by exposing your immune system to very small amounts of dead or significantly weakened pathogens.
Raw milk contains live H5N1 virus, which means it can still infect you and make you sick. Instead of contributing to your immunity, raw milk exposes you to the virus in full force, which can lead to serious illness. Any protective antibodies that may be present in raw milk are likely to be broken down in stomach acid.
In addition, people who contract bird flu from raw milk run the risk of transmitting the disease to other people or animals by allowing the virus to adapt and improve its spread between people. This increases the risk of more widespread disease outbreaks.
This article is republished from The Conversation, an independent nonprofit organization providing facts and analysis to help you understand our complex world.
It was written by: Juan Silva, Mississippi State University; Joel Komakech, Mississippi State Universityand Mandy Conrad, Mississippi State University.
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The authors do not work for, consult with, own shares in, or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.