A Doctor's Guide to the Raw Milk Debate

There is a growing sentiment in some corners of the wellness world that raw, unpasteurized milk is somehow more natural, more nutritious, and therefore better than the pasteurized milk most of us have grown up drinking. Farmers' market booths, social media influencers, and even some politicians have championed raw milk as health food. The appeal is not irrational on its face — less-processed foods often are more nutritious, and skepticism about how industrialized parts of the food system have become is not always misplaced.

But raw milk is a case where that assumption runs into a wall of evidence. Raw milk is one of the riskiest foods a person can consume: it carries serious and sometimes life-threatening risks. The case for pasteurization rests on more than a century of evidence that it saves lives without meaningfully altering milk's nutritional value.

What Is Raw Milk, and Why Is It Risky?

The udder, milking equipment, animal feces, and the farm environment are all potential sources of dangerous bacteria that can contaminate raw milk and cause food poisoning. Even healthy-looking animals from well-managed farms can shed pathogens in their milk without any visible signs of illness.

The bacteria raw milk can harbor include:

• Escherichia coli O157:H7 — produces a toxin that can cause hemolytic uremic syndrome (HUS) in young children, damaging kidneys and resulting in hospitalization and even death.

• Campylobacter — the most common bacterial cause of diarrheal illness in many countries; can trigger reactive arthritis and Guillain-Barré syndrome.

• Salmonella — causes severe diarrhea, fever, and abdominal cramping; can be fatal in young children and immunocompromised individuals.

• Listeria monocytogenes — particularly dangerous during pregnancy, causing miscarriage, stillbirth, and life-threatening newborn infections.

This is not a comprehensive or theoretical list. These pathogens cause real outbreaks, real hospitalizations, and real deaths.

The Outbreak Record Is Significant

The widespread adoption of pasteurization in the 20th century is a great public health achievement. It effectively eliminated milk as a significant vector for infections including tuberculosis, typhoid, diphtheria, and scarlet fever, diseases that killed hundreds of thousands of children annually before the practice became standard.

From 1998 to 2018, the CDC identified 202 outbreaks linked to raw milk or raw milk products in the United States. These outbreaks caused 2,645 illnesses, 228 hospitalizations, and 3 deaths. This is almost certainly an undercount: outbreak surveillance only captures illnesses that investigators can link to a shared source as part of a multi-case cluster. Sporadic, single-case illnesses — which are far harder to trace back to a specific batch of unpasteurized milk — do not show up in these figures, meaning the true burden is likely higher.

Three deaths across two recent decades might sound on its own, like a low bar to clear. But mortality alone understates the harm: a meaningful share of the 228 hospitalizations in this period involved children needing dialysis or a kidney transplant after E. coli-associated HUS — outcomes that permanently reshape a life without ever appearing in a death count.

Raw milk accounts for a tiny fraction of total U.S. dairy consumption, less than 1% according to the FDA, yet it is responsible for the majority of dairy-related illness outbreaks. A 2017 analysis in Emerging Infectious Diseases found that, per unit of product consumed, unpasteurized dairy was associated with 840 times more illnesses and 45 times more hospitalizations than pasteurized dairy, a comparison that adjusts for raw milk's much smaller market share, so it reflects risk per consumer rather than simply the fact that fewer people drink it. A 2012 analysis in Emerging Infectious Diseases similarly found that states permitting raw milk sales had significantly higher rates of raw milk-associated outbreaks than states where such sales were prohibited.

Children are especially vulnerable to severe dehydration and invasive bacterial infections. In outbreak after outbreak, a disproportionate share of the sickest patients is under age five. Children's immune systems are still developing, their kidneys are more vulnerable to toxin damage, and they are less able to fight off the systemic spread of infection. When a child develops HUS from E. coli O157:H7 in raw milk, the consequences can include dialysis, kidney transplant, or death.

What Pasteurization Is, and How It Works

Pasteurization was developed in the 1860s by French scientist Louis Pasteur, who demonstrated that heating beverages killed the microorganisms responsible for spoilage and disease. The application of this principle to milk began in earnest in the late 19th century and became widespread in the United States and Europe by the mid-20th century.

Modern pasteurization is a straightforward and highly controlled process: milk is heated to a specific temperature for a specific amount of time. Nothing is added to the milk during this process. The most commonly used method today is High-Temperature Short-Time (HTST) pasteurization, in which milk is heated to 72°C (161.6°F) for at least 15 seconds, then rapidly cooled. For comparison, water boils at 100°C (212°F), so standard pasteurization does not come close to boiling the milk. Another method, Ultra-High Temperature (UHT), heats milk to 135–150°C (275–302°F) for 1–2 seconds — above boiling — producing shelf-stable milk that requires no refrigeration until opened. This can be useful when refrigeration is unreliable, such as for emergency food reserves.

Each method is calibrated to achieve a 5-log reduction (a 99.999% kill rate) of the most heat-resistant pathogens likely to be found in milk, particularly Coxiella burnetii, the cause of Q fever, which serves as the pasteurization benchmark. All the bacteria listed above are considerably less heat-resistant than C. burnetii, meaning pasteurization eliminates them as well.

The process is also tightly monitored: commercial pasteurization equipment has flow-diversion valves that automatically reroute milk back through heating if the correct temperature is not reached.

The Nutrition Question: Does Pasteurization Diminish Milk's Value?

This is where the raw milk debate most frequently runs into trouble with the evidence. Advocates claim that pasteurization destroys beneficial enzymes, reduces vitamin content, denatures proteins, and harms beneficial bacteria. The scientific literature, accumulated over decades, paints a far more nuanced and reassuring picture. In general, the higher the temperature used, the greater the risk of affecting nutrients — but for the typical HTST method, the effect on nutritional value is minimal.

Proteins

Milk proteins — primarily casein and whey proteins — are largely unaffected by pasteurization, especially HTST. Casein, which makes up about 80% of milk protein, is highly heat-stable and remains virtually unchanged. Some minor denaturation of whey proteins (primarily β-lactoglobulin) does occur, but this does not reduce their nutritional value — denatured proteins are digested just as efficiently as native ones. Studies comparing the amino acid composition of pasteurized and raw milk have found it to be essentially identical.

Fat and Fat-Soluble Vitamins

Milk fat is unaffected by pasteurization temperatures. The fat-soluble vitamins A, D, E, and K are similarly stable under pasteurization conditions, with studies comparing pasteurized and raw milk finding no meaningful decreases in these nutrients.

Water-Soluble Vitamins and Minerals

Here there is a small, measurable effect. Pasteurization causes modest reductions in some heat-sensitive water-soluble vitamins, particularly vitamin C and thiamine (B1), though milk is not a significant dietary source of either. A glass of milk contributes only a few milligrams of vitamin C; oranges, peppers, and broccoli are the vitamin C-rich foods in a typical diet. The CDC and FDA have both concluded that these minor losses are nutritionally inconsequential for anyone eating a reasonably varied diet. Milk's small folate content may also be reduced slightly by standard HTST pasteurization.

Riboflavin (vitamin B2), which does meaningfully contribute to the diet, shows a small reduction with standard HTST pasteurization, though pasteurized milk retains enough B2 to remain a good dietary source of it. The concentration and bioavailability of calcium is the same in raw and pasteurized milk.

Enzymes

Raw milk enthusiasts frequently cite the destruction of enzymes, particularly lactase, lipase, and phosphatase, as a major reason to prefer unpasteurized milk. But these bovine enzymes are inactivated in the GI tract and have no special role in human digestion; the notion that raw milk's own enzymes help a person digest it is not supported by physiological evidence.

Lactase, specifically, is produced by the cells lining your own small intestine. If you are lactose intolerant, it is because your body produces insufficient lactase, and consuming raw milk's lactase, which is destroyed in your stomach before it can do anything, does not address that deficit.

Beneficial Bacteria

Some advocates argue that raw milk contains beneficial probiotic bacteria destroyed by pasteurization. It is true that raw milk contains a diverse microbial community, but it is not a curated one. It is whatever bacteria happens to be present in the udder and milking environment, which can and often does include pathogens. The “beneficial” organisms in raw milk are not present in standardized therapeutic concentrations, are not necessarily the strains with documented probiotic effects, and cannot be assumed safe simply because they are natural. Fermented dairy products like yogurt and kefir, made from pasteurized milk and then inoculated with specific, well-studied bacterial strains, are a far more reliable, evidence-based way to consume beneficial bacteria.

What About the “Farm Effect” on Allergies and Asthma?

One piece of evidence raw milk advocates point to is real and worth engaging directly. European cohort studies, including the PARSIFAL study and the GABRIELA study, found that children raised on farms, who were often also exposed to raw milk, had lower rates of asthma and allergic sensitization than children raised elsewhere. This research is legitimate, and it has motivated genuine scientific interest in what is now called the “farm effect.”

It is worth being precise about what this research does and does not show. These are observational studies of a broad rural upbringing, including exposure to livestock, barn dust, and a diverse environmental microbiome, not controlled trials isolating raw milk as the active variable. Children raised on farms differ from children who are not in many ways that could plausibly affect immune development, and the researchers behind this work have not concluded that unpasteurized milk itself is the protective factor. No major pediatric or allergy organization recommends giving children raw milk to prevent asthma. If a specific protective component is eventually isolated, the public-health path forward is to identify and deliver it safely, not to expose children to a product that also reliably carries E. coli, Salmonella, and Listeria risk on the chance that part of it might help.

The Bottom Line on Nutrition

The scientific consensus, from the FDA, the CDC, the American Academy of Pediatrics, the World Health Organization, and major nutrition research bodies, is that pasteurized milk is nutritionally equivalent to raw milk for all practical purposes. A 2011 review in the Journal of Food Protection examined the existing evidence and concluded that the health benefits of pasteurized milk far outweigh any benefits, if they exist at all, of raw milk. No major nutritional authority recommends raw milk over pasteurized milk.

Who Bears the Real Risk?

It is worth being clear about who is most likely to be harmed by raw milk consumption:

• Infants and young children, whose immune systems cannot mount an adequate response to invasive pathogens.

• Pregnant women, for whom Listeria infection can cause miscarriage or death.

• Older adults, whose immune responses decline with age.

• People with HIV/AIDS, cancer, diabetes, or other conditions that impair immunity.

• People taking immunosuppressants after organ transplants or for autoimmune conditions.

Outbreak investigations consistently show this in practice: hospitalized patients skew disproportionately young, even in households where the adults who chose to drink raw milk experienced mild symptoms or none at all, a pattern that reflects how much more severely a developing immune system responds to the same pathogen exposure.

The Regulatory Picture

In the United States, the FDA prohibits the interstate sale of raw milk for human consumption. Individual states may permit in-state sales, and as of 2024, roughly 30 states allow some form of raw milk sale, either in stores or directly from farms.

One nuance worth noting: the federal ban applies to raw fluid milk sold for direct consumption. Raw milk cheese aged 60 days or longer is treated differently under FDA rules and can legally be sold across state lines, on the premise that the aging process reduces pathogen loads. Some public health researchers have questioned whether a 60-day aging period reliably eliminates risk from more resistant pathogens, and this standard remains a point of ongoing scientific discussion rather than settled science.  Earlier this year in the US there was an outbreak of E. coli infections from consumption of contaminated raw cheese that was aged 12 months prior to sale of it, resulting in nine ill people, three of whom were hospitalized and one of whom developed hemolytic uremic syndrome. 

In many other developed countries, including Canada, Australia, and most of the European Union, the sale of raw drinking milk is either prohibited or very tightly restricted.

Raw Milk Debate Conclusion: Progress Should Not Be Forgotten

There is something understandable about the desire to return to less-processed, more natural foods. But nostalgia is not a guide to food safety, and “natural” is not a synonym for “safe.” Raw milk is a product that has been repeatedly linked to serious illness, and the claim that it offers nutritional benefits sufficient to justify that risk is not supported by the evidence.

The clearest way to see this debate is as a question of asymmetry. The potential upside, marginally higher levels of a couple of vitamins your diet almost certainly supplies from other sources, or an unproven protective effect against allergies that have not been isolated to milk itself, is small and uncertain. The potential downside, a bacterial infection that can cause kidney failure, miscarriage, or death, particularly in a child, a pregnant woman, or someone immunocompromised, is severe and sometimes irreversible. When the upside is marginal and the downside is catastrophic, even a low probability of harm is a bad trade. That asymmetry, more than any single statistic, is the case for pasteurization.

Even high-quality raw milk cannot be guaranteed pathogen-free, given that healthy animals shed pathogens asymptomatically and consumers have no reliable way to verify farm practices. The most vulnerable populations — children, pregnant people, elderly people, and immunocompromised people — especially should not consume raw milk or products made from unpasteurized milk, including cheese, butter, yogurt, pudding, or ice cream, from any species, including cows, sheep, and goats.

This post reflects the current scientific consensus, established by the CDC, FDA, WHO, and peer-reviewed nutritional research. For specific medical or dietary advice, consult a qualified healthcare provider.

References

• Alfvén, T., Braun-Fahrländer, C., Brunekreef, B., et al. (2006). Allergic Diseases and Atopic Sensitization in Children Related to Farming and Anthroposophic Lifestyle — the PARSIFAL Study. Allergy.

• CDC Investigation Update: E. coli Outbreak, March 2026

• CDC Listeria Annual Summary, 2014.

• Costard, S., Espejo, L., Groenendaal, H., & Zagmutt, F.J. (2017). Outbreak-Related Disease Burden Associated With Consumption of Unpasteurized Cow's Milk and Cheese, United States, 2009–2014. Emerging Infectious Diseases.

• de Klerk, J.N., & Robinson, P.A. (2022). Drivers and Hazards of Consumption of Unpasteurised Bovine Milk and Milk Products in High-Income Countries. PeerJ.

• Koski, L., Kisselburgh, H., Landsman, L., et al. (2022). Foodborne Illness Outbreaks Linked to Unpasteurised Milk and Relationship to Changes in State Laws — United States, 1998–2018. Epidemiology and Infection.

• Lejeune, J.T., & Rajala-Schultz, P.J. (2009). Food Safety: Unpasteurized Milk: A Continued Public Health Threat. Clinical Infectious Diseases.

• Loss, G., Apprich, S., Waser, M., et al. (2011). The Protective Effect of Farm Milk Consumption on Childhood Asthma and Atopy: The GABRIELA Study. Journal of Allergy and Clinical Immunology.

• Lucey, J.A. (2015). Raw milk consumption: risks and benefits. Nutrition and Food Science, 50(4), 189–193.

• MacDonald, L.E., Brett, J., Kelton, D., Majowicz, S.E., Snedeker, K., & Sargeant, J.M. (2011). A systematic review and meta-analysis of the effects of pasteurization on milk vitamins, and evidence for raw milk consumption and other health-related outcomes. Journal of Food Protection, 74(11), 1814–1832.

• Mungai EA, Behravesh C, Gould L. Increased Outbreaks Associated with Nonpasteurized Milk, United States, 2007–2012. Emerg Infect Dis. 2015;21(1):119-122. 

• Pink Book, 14th edition, 2021. CDC. cdc.gov/pinkbook

• Raw Milk Misconceptions and the Danger of Raw Milk Consumption. FDA.

• Red Book: Report of the Committee on Infectious Diseases, 2024–2027. American Academy of Pediatrics (AAP). aap.org

• Sebastianski, M., Bridger, N.A., Featherstone, R.M., & Robinson, J.L. (2022). Disease Outbreaks Linked to Pasteurized and Unpasteurized Dairy Products in Canada and the United States: A Systematic Review. Canadian Journal of Public Health.

• Sonnier, J.L., Karns, J.S., Lombard, J.E., et al. (2018). Prevalence of Salmonella enterica, Listeria monocytogenes, and Pathogenic E. coli in Bulk Tank Milk and Milk Filters From US Dairy Operations in the National Animal Health Monitoring System Dairy 2014 Study. Journal of Dairy Science.

• Weinstein, E., Lamba, K., Bond, C., et al. (2025). Outbreak of Salmonella Typhimurium Infections Linked to Commercially Distributed Raw Milk — California and Four Other States, September 2023–March 2024. MMWR.

• Williams, E.N., Van Doren, J.M., Leonard, C.L., & Datta, A.R. (2023). Prevalence of Listeria monocytogenes, Salmonella spp., Shiga Toxin-Producing E. coli, and Campylobacter spp. in Raw Milk in the United States Between 2000 and 2019: A Systematic Review and Meta-Analysis. Journal of Food Protection.