Nutrition Fact Check: Raw Milk

In recent years, the popularity of consuming unpasteurized or raw milk has grown, developing into a nationwide trend despite the well-documented risks of foodborne illness. ^{[1] [1]} Oliver SP, Boor KJ, Murphy SC, Murinda SE. Food safety hazards associated with consumption of raw milk. Foodborne Pathog Dis. Sep 2009;6(7):793-806. doi:10.1089/fpd.2009.0302 Supporters and producers of raw milk claim that it can help reduce conditions such as allergies, autism, inflammatory bowel disease and lactose intolerance. ^{[2] [2]} Braun-Fahrländer C, von Mutius E. Can farm milk consumption prevent allergic diseases? Clin Exp Allergy. Jan 2011;41(1):29-35. doi:10.1111/j.1365-2222.2010.03665.x, ^{[3] [3]} Riedler J, Braun-Fahrländer C, Eder W, et al. Exposure to farming in early life and development of asthma and allergy: a cross-sectional survey. Lancet. Oct 6 2001;358(9288):1129-33. doi:10.1016/s0140-6736(01)06252-3, ^{[4] [4]} Mummah S, Oelrich B, Hope J, Vu Q, Gardner CD. Effect of raw milk on lactose intolerance: a randomized controlled pilot study. Ann Fam Med. Mar-Apr 2014;12(2):134-41. At the same time, this trend has prompted considerable public discussion regarding the true balance of potential benefits and health risks associated with consuming unpasteurized milk. ^{[5] [5]} Melini F, Melini V, Luziatelli F, Ruzzi M. Raw and Heat-Treated Milk: From Public Health Risks to Nutritional Quality. Beverages. 2017;3(4):54. Lando et al. (2022) analyzed nationally representative data from 2016 and 2019 to characterize U.S. adults who consume unpasteurized milk and to estimate consumption frequency. Overall, 4.4% of adults reported drinking raw milk at least once in the previous year. Notably, nearly one-quarter (23.2%) of those who drank raw milk in the past year reported weekly or more frequent intake. ^{[6] [6]} Lando AM, Bazaco MC, Parker CC, Ferguson M. Characteristics of U.S. Consumers Reporting Past Year Intake of Raw (Unpasteurized) Milk: Results from the 2016 Food Safety Survey and 2019 Food Safety and Nutrition Survey. J Food Prot. Jul 1 2022;85(7):1036-1043. doi:10.4315/jfp-21-407

Raw milk refers to milk that has not undergone pasteurization, a process that heats milk to a specific temperature and then cools it quickly. ^{[7] [7]} Lejeune JT, Rajala-Schultz PJ. Food safety: unpasteurized milk: a continued public health threat. Clin Infect Dis. Jan 1 2009;48(1):93-100. doi:10.1086/595007 The key purpose of pasteurization is to eliminate harmful microorganisms. This includes the elimination of disease-causing microorganisms; destroying most spoilage microbes; and deactivating enzymes that can shorten shelf life. Because raw milk has not undergone pasteurization, it can contain harmful bacteria, and consuming it can lead to symptoms including nausea, vomiting, diarrhea, fever, abdominal pain, and headaches. In some cases, it can cause severe or life-threatening illnesses. Certain groups, such as children under 5 years of age, adults 65 and older, individuals with compromised immune systems and pregnant people, face a higher risk of severe illness or death if they become infected with enteric pathogens. ^{[8] [8]} Mungai EA, Behravesh CB, Gould LH. Increased outbreaks associated with nonpasteurized milk, United States, 2007-2012. Emerg Infect Dis. Jan 2015;21(1):119-22. doi:10.3201/eid2101.140447, ^{[9] [9]} Costard S, Espejo L, Groenendaal H, Zagmutt FJ. Outbreak-Related Disease Burden Associated with Consumption of Unpasteurized Cow's Milk and Cheese, United States, 2009-2014. Emerg Infect Dis. Jun 2017;23(6):957-964. doi:10.3201/eid2306.151603

Before pasteurization became common in the late 1800s, milk from animals was a leading source of foodborne disease. ^{[10] [10]} Steele JH. History, trends, and extent of pasteurization. J Am Vet Med Assoc. Jul 15 2000;217(2):175-8. doi:10.2460/javma.2000.217.175 Once its value as a public health intervention was recognized, pasteurization became mandatory in several regions of Canada and the United States during the early 20th century and has been required nationwide in Canada since 1991. ^{[10] [10]} Steele JH. History, trends, and extent of pasteurization. J Am Vet Med Assoc. Jul 15 2000;217(2):175-8. doi:10.2460/javma.2000.217.175, ^{[11] [11]} Raw or unpasteurized milk (Health Canada) (2024). In 1987, the U.S. Food and Drug Administration (FDA) banned the interstate sale of raw milk intended for direct consumer use. Despite this federal restriction, many states permit the sale of these products within their borders, and outbreaks of illnesses linked to consuming unpasteurized dairy products continue to be reported. ^{[12] [12]} Gould LH, Mungai E, Behravesh CB. Outbreaks attributed to cheese: differences between outbreaks caused by unpasteurized and pasteurized dairy products, United States, 1998-2011. Foodborne Pathog Dis. Jul 2014;11(7):545-51. doi:10.1089/fpd.2013.1650, ^{[13] [13]} CDC study: increase in raw milk food poisoning outbreaks. (Food Poison. Bull) (2015.). A foodborne disease outbreak occurs when at least two cases of a similar illness results from ingestion of a common food. ^{[8] [8]} Mungai EA, Behravesh CB, Gould LH. Increased outbreaks associated with nonpasteurized milk, United States, 2007-2012. Emerg Infect Dis. Jan 2015;21(1):119-22. doi:10.3201/eid2101.140447

Pasteurization Process

Established Established pasteurization parameters are specifically intended to inactivate Mycobacterium tuberculosis and Coxiella burnetiid. ^{[14] [14]} Codex Alimentarius. Standard CAC-RCP57-2004: Code on Hygienic Practice for Milk and Milk Products. 2004 (2004.)., ^{[15] [15]} Public Health Service and Food and Drug Admin. 2003. Grade A Pasteurized Milk Ordinance (2019). Pasteurization methods are generally categorized by the temperature and duration of heat. High-temperature, short-time (HTST) pasteurization methods are often called 'low pasteurization' and typically heat milk to 162°F (72°C) for 15 seconds. Low-temperature, long-time (LTLT) pasteurization, on the other hand, involves heating milk to 145°F (63°C) for 30 minutes or 154°F (68°C) for 10 minutes. ^{[5] [5]} Melini F, Melini V, Luziatelli F, Ruzzi M. Raw and Heat-Treated Milk: From Public Health Risks to Nutritional Quality. Beverages. 2017;3(4):54., ^{[14] [14]} Codex Alimentarius. Standard CAC-RCP57-2004: Code on Hygienic Practice for Milk and Milk Products. 2004 (2004.). Safety precautions do not end with pasteurization. Quickly cooling the milk after heating, maintaining sanitation when handling and storing it in a sealed container at 40°F (4°C) or lower are all key steps in keeping milk safe.

Nutrient Composition of Raw and Pasteurized Milk

The Center for Disease Control and Prevention (CDC) and the FDA report that pasteurized milk provides comparable nutrients to raw milk but without the associated safety risks. ^{[16] [16]} "Raw Milk Misconceptions and the Danger of Raw Milk Consumption." U.S. Food and Drug Administration, May 3, 2024. https://www.fda.gov/food/buy-store-serve-safe-food/raw-milk-misconceptions-and-danger-raw-milk-consumption., ^{[17] [17]} "Raw Milk." Centers for Disease Control and Prevention, January 31, 2025. https://www.cdc.gov/food-safety/foods/raw-milk. Research from single studies and meta-analyses consistently show no significant nutritional advantage of raw milk over pasteurized milk. ^{[18] [18]} Rabbani A, Ayyash M, D'Costa CDC, Chen G, Xu Y, Kamal-Eldin A. Effect of Heat Pasteurization and Sterilization on Milk Safety, Composition, Sensory Properties, and Nutritional Quality. Foods. Apr 14 2025;14(8)doi:10.3390/foods14081342, ^{[19] [19]} Wang Y, Xiao R, Liu S, et al. The Impact of Thermal Treatment Intensity on Proteins, Fatty Acids, Macro/Micro-Nutrients, Flavor, and Heating Markers of Milk-A Comprehensive Review. Int J Mol Sci. Aug 8 2024;25(16)doi:10.3390/ijms25168670, ^{[20] [20]} Macdonald LE, Brett J, Kelton D, Majowicz SE, Snedeker K, Sargeant JM. 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. J Food Prot. Nov 2011;74(11):1814-32. doi:10.4315/0362-028x.Jfp-10-269 Pasteurization does not significantly alter milk protein quality. Although minor denaturation of whey proteins (<7%) may occur, this has no measurable effect on their nutritional value. ^{[21] [21]} Lucey JA. Raw Milk Consumption: Risks and Benefits. Nutr Today. Jul 2015;50(4):189-193. doi:10.1097/nt.0000000000000108 Pasteurization does not significantly affect mineral content, as minerals are largely heat-stable. Small losses (≤10%) may occur for certain vitamins, including vitamin C, E, B1, B6, B12 and folate; ^{[19] [19]} Wang Y, Xiao R, Liu S, et al. The Impact of Thermal Treatment Intensity on Proteins, Fatty Acids, Macro/Micro-Nutrients, Flavor, and Heating Markers of Milk-A Comprehensive Review. Int J Mol Sci. Aug 8 2024;25(16)doi:10.3390/ijms25168670, ^{[20] [20]} Macdonald LE, Brett J, Kelton D, Majowicz SE, Snedeker K, Sargeant JM. 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. J Food Prot. Nov 2011;74(11):1814-32. doi:10.4315/0362-028x.Jfp-10-269 however, this has little impact on total dietary intakes, as most of these vitamins, besides B12, are present in small amounts even before pasteurization. Riboflavin (B2), despite being largely heat stable, has been shown to be lower in pasteurized milk. ^{[20] [20]} Macdonald LE, Brett J, Kelton D, Majowicz SE, Snedeker K, Sargeant JM. 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. J Food Prot. Nov 2011;74(11):1814-32. doi:10.4315/0362-028x.Jfp-10-269 Despite the statistically significant but small reduction, riboflavin content of milk remains relatively high compared to many foods. Given the modest nutritional changes, many experts and regulatory bodies conclude that the safety benefits of pasteurization generally outweigh the downsides.

Associated Risks and Health Impacts of Raw Milk

Risks Associated with Raw Milk Consumption

By the early 20th century, raw milk was recognized as a major source of infectious diseases, including diphtheria, typhoid, tuberculosis and brucellosis. By 1938, it accounted for approximately 25% of foodborne and waterborne outbreaks in the United States, primarily due to contamination from infected animals and unsanitary handling practices. ^{[15] [15]} Public Health Service and Food and Drug Admin. 2003. Grade A Pasteurized Milk Ordinance (2019).

While overall dairy-related illnesses have declined since 1938, outbreaks in the past two decades have primarily involved Salmonella enterica, Listeria monocytogenes, Campylobacter jejuni, and E. coli O157:H7. ^{[22] [22]} Institute of Medicine (US) and National Research Council (US) Committee on the Review of the Use of Scientific Criteria and Performance Standards for Safe Food. Scientific Criteria to Ensure Safe Food. Washington (DC): National Academies Press (US); 2003. Available from: https://www.ncbi.nlm.nih.gov/books/NBK221565/ doi: 10.17226/10690, ^{[23] [23]} Sebastianski M, Bridger NA, Featherstone RM, Robinson JL. Disease outbreaks linked to pasteurized and unpasteurized dairy products in Canada and the United States: a systematic review. Canadian Journal of Public Health. 2022 Aug;113(4):569-78. These pathogens can contaminate milk from healthy cows, often via manure or un-sanitized equipment. Prevalence of pathogens in bulk tank milk ranges from 0.9% to 12.6% and is influenced by farm management, hygiene, herd health, season, region and sampling methods. ^{[10] [10]} Steele JH. History, trends, and extent of pasteurization. J Am Vet Med Assoc. Jul 15 2000;217(2):175-8. doi:10.2460/javma.2000.217.175, ^{[24] [24]} Oliver SP, Jayarao BM, Almeida RA. Foodborne pathogens in milk and the dairy farm environment: food safety and public health implications. Foodborne Pathog Dis. Summer 2005;2(2):115-29. doi:10.1089/fpd.2005.2.115

Between 2000 and 2006, 40 outbreaks linked to raw milk consumption were reported in the U.S., resulting in approximately 600 illnesses, primarily caused by Campylobacter (33 outbreaks) and E. coli O157:H7 (six outbreaks). ^{[25] [25]} Centers for Disease Control and Prevention. 2008d. Outbreak Surveillance, Annual listing of Foodborne Disease Outbreaks, United States: 2000-2006. Available at http://www.cdc.gov/foodborneoutbreaks/outbreak_data.htm. Accessed on November 28, 2008., ^{[26] [26]} Center for Science in the Public Interest. 2008. Outbreak alert database. CSPI, Washington, D.C Available at: http://www.cspinet.org/foodsafety/outbreak/pathogen.php Accessed November 28, 2008 Notable pediatric cases included severe hemolytic urea syndrome (HUS) following consumption from cow-leasing programs in Washington (2005) ^{[27] [27]} Escherichia coli O157:H7 infection associated with drinking raw milk --- Washington and Oregon, November--December 2005. (MMWR) 165-167. (2007.). and California (2006) ^{[28] [28]} Escherichia coli 0157:H7 infections in children associated with raw milk and raw colostrum from cows --- California, 2006 (MMWR) 625-628. (2008. )., prompting hospitalization and legal action. The largest Campylobacter outbreak occurred in Wisconsin in 2001 (75 cases), ^{[29] [29]} Outbreak of Campylobacter jejuni infections associated with drinking unpasteurized milk procured through a cow-leasing program - Wisconsin, 2001. (MMWR) 548-549. (2002.). and a multi-state Salmonella outbreak (62 cases) led the implicated Ohio dairy to relinquish its license. ^{[30] [1]} Multi-state outbreak of Salmonella Serotype Typhimurium infections associated with drinking unpasteurized milk --- Illinois, Indiana, Ohio, & Tennessee, 2002—2003. (MMWR July 4, 2003.) 612-615. (2003.). In 2007–2008, raw milk outbreaks continued, including Salmonella in Pennsylvania (29 cases) ^{[31] [31]} Salmonella Typhimurium infection associated with raw milk and cheese consumption --- Pennsylvania, 2007. (MMWR November 9, 2007) 1161 (2007.).; Campylobacter in Kansas, Utah, and California (16–26 cases, one case with Guillain-Barré Syndrome); and E. coli O157:H7 in Connecticut and Missouri, with several pediatric HUS cases reported. ^{[32] [32]} Campylobacteriosis outbreak associated with unpasteurized milk - Reno County and Butler County, August–December 2007. (Kansas Department of Health and Environment.) (2007.)., ^{[33] [33]} Unpasteurized Milk-Associated Diseases in Utah. (Report to the Natural Resources, Agriculture & Environment Interim Committee and the Health & Human Services Interim Committees.) (2008.)., ^{[34] [34]} California Department of Public Health - CDPH. Campylobacteriosis among persons consuming unpasteurig unpasteurized milk from a cow leasing program, Del Norte County, May-June 2008. Infectious Diseases Branch, Division of Communicable Disease Control, Center for Infectious Diseases. 2008. Accessed 11/25/2025.

Since 2000, raw milk cheese has also been linked to several outbreaks. Notable events include a 2007 Campylobacter outbreak in Kansas (67 cases) ^{[35] [35]} Campylobacter jejuni infection associated with unpasteurized milk and cheese--Kansas, 2007. MMWR Morb Mortal Wkly Rep. Jan 2 2009;57(51):1377-9., Salmonella outbreaks in Illinois (85 cases, 2006–2007) ^{[36] [36]} Outbreak of multidrug-resistant Salmonella enterica serotype Newport infections associated with consumption of unpasteurized Mexican-style aged cheese--Illinois, March 2006-April 2007. MMWR Morb Mortal Wkly Rep. Apr 25 2008;57(16):432-5., and a 2017 outbreak of Listeria monocytogenes in four states (8 cases). ^{[37] [37]} "2017 Outbreak of Listeria Infections Linked to Soft Raw Milk Cheese Made by Vulto Creamery." Centers for Disease Control and Prevention, May 3, 2017. https://archive.cdc.gov/#/details?url=https://www.cdc.gov/listeria/outbreaks/soft-cheese-03-17/index.html. Additionally, 35 cases of Mycobacterium bovis were reported in New York City, primarily linked to imported fresh cheese. ^{[38] [38]} Human tuberculosis caused by Mycobacterium bovis - New York City, 2001-2004. (Centers for Disease Control and Prevention.) 605-608 (2005).

According to Koski et al 2022, from 2013–2018, 75 outbreaks and 675 illnesses were linked to unpasteurized milk in the U.S., with nearly half affecting children and adolescents. Most outbreaks occurred in states permitting sales. Jurisdictions allowing retail sales experienced significantly more outbreaks than those prohibiting or restricting sales to on-farm sales only. These results indicate that greater legal availability of unpasteurized milk is associated with increased outbreak risk. ^{[39] [39]} Koski L, Kisselburgh H, Landsman L, et al. Foodborne illness outbreaks linked to unpasteurised milk and relationship to changes in state laws - United States, 1998-2018. Epidemiol Infect. Oct 25 2022;150:e183. doi:10.1017/s0950268822001649

In October 2023, an outbreak of 171 Salmonella Typhimurium cases was linked to raw milk, primarily affecting children under 18. Whole-genome sequencing confirmed the outbreak strain in raw milk, aged cheese and environmental samples. The farm that produced this milk voluntarily recalled products within a week. This outbreak highlights the potential for commercially distributed raw dairy to cause widespread illness and underscores the importance of public awareness of associated risks, especially vulnerable populations. ^{[40] [40]} Weinstein E, Lamba K, Bond C, et al. Outbreak of Salmonella Typhimurium Infections Linked to Commercially Distributed Raw Milk - California and Four Other States, September 2023-March 2024. MMWR Morb Mortal Wkly Rep. Jul 24 2025;74(27):433-438. doi:10.15585/mmwr.mm7427a1

In November 2025, Illinois Department of Public Health identified an outbreak of eleven cases of Campylobacter infection that appear to be linked to consumption of raw milk from a common source. ^{[41] [41]} IDPH Issues Reminder About Potential Hazards of Consuming Raw Milk. (Ilinois Department of Public Health.) (2025.).

While raw milk consumption is associated with a higher number of outbreaks, pasteurized milk is not exempt from causing foodborne illness. However, between 2009 and 2014, unpasteurized dairy products were found to cause 840 times more illnesses and 45 times more hospitalizations than pasteurized products. ^{[41] [41]} IDPH Issues Reminder About Potential Hazards of Consuming Raw Milk. (Ilinois Department of Public Health.) (2025.). From 2009-2015, 80% of foodborne disease outbreaks caused by dairy were linked to unpasteurized dairy. ^{[42] [42]} Surveillance for Foodborne Disease Outbreaks — United States, 2009–2015. (MMWR Surveill Summ ) 1-11. (2018.). The higher number of reported raw milk outbreaks may be partly due to detection bias. ^{[43] [43]} Berge AC, Baars T. Raw milk producers with high levels of hygiene and safety. Epidemiol Infect. Jan 31 2020;148:e14. doi:10.1017/s0950268820000060 Raw milk use is often easier to recognize within a small consumer group, whereas linking illness to pasteurized milk can be more difficult, as it is more widely consumed and may not immediately be considered as a culprit. ^{[43] [43]} Berge AC, Baars T. Raw milk producers with high levels of hygiene and safety. Epidemiol Infect. Jan 31 2020;148:e14. doi:10.1017/s0950268820000060 Despite this, raw milk still presents a significant risk, with some surveys of bulk tank milk and milk filters finding Salmonella contamination in 18% of dairy operations in the U.S. ^{[44] [44]} Sonnier JL, Karns JS, Lombard JE, et al. Prevalence of Salmonella enterica, Listeria monocytogenes, and pathogenic Escherichia coli in bulk tank milk and milk filters from US dairy operations in the National Animal Health Monitoring System Dairy 2014 study. J Dairy Sci. Mar 2018;101(3):1943-1956. doi:10.3168/jds.2017-13546 As farm management, hygiene, herd health, season and region can influence the prevalence of pathogens in bulk tank milk awaiting pasteurization, these same factors influence the safety of raw milk, highlighting the critical importance of high standards of safe handling practices in the production of milk.

Health Claims About Raw Milk Consumption

Although several health benefits are commonly claimed by proponents of raw milk, available scientific evidence is sparse, largely observational and confounded by environmental and lifestyle factors. These claims generally fall into two broad categories: digestive health and allergy and immune-related outcomes.

Digestive Health

According to the FDA, raw milk does not treat lactose intolerance. ^{[16] [16]} "Raw Milk Misconceptions and the Danger of Raw Milk Consumption." U.S. Food and Drug Administration, May 3, 2024. https://www.fda.gov/food/buy-store-serve-safe-food/raw-milk-misconceptions-and-danger-raw-milk-consumption. Lactose, a disaccharide naturally present in milk at approximately 4.8% in bovine milk, ^{[16] [16]} "Raw Milk Misconceptions and the Danger of Raw Milk Consumption." U.S. Food and Drug Administration, May 3, 2024. https://www.fda.gov/food/buy-store-serve-safe-food/raw-milk-misconceptions-and-danger-raw-milk-consumption. requires the enzyme lactase (β-galactosidase) for digestion. Individuals with lactose intolerance lack sufficient lactase and consumption of any milk, raw or pasteurized, can trigger symptoms. Milk does not naturally contain lactase.

A randomized trial of 16 adults indicated that raw milk did not improve lactose malabsorption or lessen lactose-intolerance symptoms compared with pasteurized milk in adults with confirmed lactose malabsorption. ^{[4] [4]} Mummah S, Oelrich B, Hope J, Vu Q, Gardner CD. Effect of raw milk on lactose intolerance: a randomized controlled pilot study. Ann Fam Med. Mar-Apr 2014;12(2):134-41. These findings do not substantiate common anecdotal claims that raw milk alleviates lactose-intolerance symptoms.

Claims that raw milk is tolerated because it contains lactase from probiotic bacteria are unfounded, as raw milk does not harbor significant populations of probiotic organisms. Some lactic acid bacteria are considered probiotics, but key strains like Bifidobacteria and Lactobacillus acidophilus occur at very low levels in raw bovine milk. Bifidobacteria in raw milk may indicate fecal contamination and incidental presence through contamination does not meet the requirements for effective probiotic use in commercial products. ^{[5] [5]} Melini F, Melini V, Luziatelli F, Ruzzi M. Raw and Heat-Treated Milk: From Public Health Risks to Nutritional Quality. Beverages. 2017;3(4):54., ^{[21] [21]} Lucey JA. Raw Milk Consumption: Risks and Benefits. Nutr Today. Jul 2015;50(4):189-193. doi:10.1097/nt.0000000000000108

A recent study examined fecal samples of 24 adults before and after a 12-week on-site farm program consisting of cooking classes and consuming a diet rich in fresh, local produce and unpasteurized dairy. ^{[45] [45]} Butler MI, Bastiaanssen TFS, Long-Smith C, et al. Recipe for a Healthy Gut: Intake of Unpasteurised Milk Is Associated with Increased Lactobacillus Abundance in the Human Gut Microbiome. Nutrients. May 19 2020;12(5)doi:10.3390/nu12051468 There was a significant increase in Lactobacillus abundance in stool samples after the 12-week intervention, which the authors associated with higher intake of unpasteurized dairy. ^{[45] [45]} Butler MI, Bastiaanssen TFS, Long-Smith C, et al. Recipe for a Healthy Gut: Intake of Unpasteurised Milk Is Associated with Increased Lactobacillus Abundance in the Human Gut Microbiome. Nutrients. May 19 2020;12(5)doi:10.3390/nu12051468 However, the small sample size, lack of a control group and numerous dietary and environmental changes inherent to the farm setting, limit causal interpretation. The study further relied on a food frequency questionnaire to measure intake, and the intensive cooking classes may have improved participant reporting accuracy. Moreover, the food frequency questionnaire does not capture differences in food quality; for instance, fresh seasonal vegetables from the farm can differ nutritionally and microbiologically from canned or mass-produced options participants may have consumed previously, which could influence the gut microbiome independently of raw milk. These findings should therefore be considered preliminary. Importantly, any potential microbiome effects of unpasteurized dairy must be weighed against the well-established public health risks associated with raw milk consumption.

Allergy and Immune-Related Outcomes

Evidence from Brick et al (2019) showed that children who consume raw farm milk have lower rates of asthma, allergies and respiratory infections. ^{[46] [46]} Brick T, Hettinga K, Kirchner B, Pfaffl MW, Ege MJ. The Beneficial Effect of Farm Milk Consumption on Asthma, Allergies, and Infections: From Meta-Analysis of Evidence to Clinical Trial. J Allergy Clin Immunol Pract. Mar 2020;8(3):878-889.e3. doi:10.1016/j.jaip.2019.11.017 These findings were hypothesized to be related to the beneficial effects of some bioactive components that are lost during pasteurization. However, this meta-analysis was based on observational studies, thus limited by range of exposure, confounding factors and information bias. Because raw milk carries infection risks, the authors emphasize that it cannot be recommended as is. Instead, they describe the development of the Milk Against Respiratory Tract Infections and Asthma (MARTHA) clinical trial, which plans on testing whether safe, minimally processed milk that preserves these protective components can offer similar health benefits without the dangers of raw milk.

Several epidemiological studies suggest that early-life exposure to farm environments, including the consumption of unpasteurized milk, is associated with lower rates of asthma, allergies and atopic sensitization in children. ^{[47] [47]} Loss G, Depner M, Ulfman LH, et al. Consumption of unprocessed cow's milk protects infants from common respiratory infections. J Allergy Clin Immunol. Jan 2015;135(1):56-62. doi:10.1016/j.jaci.2014.08.044, ^{[48] [48]} Depner M, Ege MJ, Genuneit J, et al. Atopic sensitization in the first year of life. J Allergy Clin Immunol. Mar 2013;131(3):781-8. doi:10.1016/j.jaci.2012.11.048, ^{[49] [49]} Loss G, Apprich S, Waser M, et al. The protective effect of farm milk consumption on childhood asthma and atopy: the GABRIELA study. J Allergy Clin Immunol. Oct 2011;128(4):766-773.e4. doi:10.1016/j.jaci.2011.07.048, ^{[50] [50]} Perkin MR, Strachan DP. Which aspects of the farming lifestyle explain the inverse association with childhood allergy? J Allergy Clin Immunol. Jun 2006;117(6):1374-81. doi:10.1016/j.jaci.2006.03.008, ^{[51] [51]} Waser M, Michels KB, Bieli C, et al. Inverse association of farm milk consumption with asthma and allergy in rural and suburban populations across Europe. Clin Exp Allergy. May 2007;37(5):661-70. doi:10.1111/j.1365-2222.2006.02640.x Raw milk consumption in particular has repeatedly been linked to protective effects, especially when introduced during infancy or even prenatally. However, these findings are largely observational, often rely on self-reported milk handling practices and do not outweigh the well-documented microbiological risks of consuming raw milk. Further, the CDC does not recommend introducing any cow's milk to infants until 12 months of age. ^{[52] [52]} "Cow's Milk and Milk Alternatives." Infant and Toddler Nutrition, March 20, 2025. https://www.cdc.gov/infant-toddler-nutrition/foods-and-drinks/cows-milk-and-milk-alternatives.html. Consequently, despite potential associations with reduced allergic disease, public health agencies continue to advise against the consumption of raw milk.

The Prevention of Allergy Risk Factors for Sensitization in Children Related to Farming and Anthroposophic Lifestyle (PARSIFAL) study reported an inverse association between farm milk consumption and asthma or allergy but did not distinguish between raw or pasteurized milk. ^{[51] [51]} Waser M, Michels KB, Bieli C, et al. Inverse association of farm milk consumption with asthma and allergy in rural and suburban populations across Europe. Clin Exp Allergy. May 2007;37(5):661-70. doi:10.1111/j.1365-2222.2006.02640.x Approximately half of the farm milk was boiled, and the study could not verify raw milk status. The authors cautioned that raw milk may contain pathogens such as Salmonella and should not be recommended as a preventive measure.

Studies also indicate that raw and pasteurized milk have similar allergenic potential. Animal and human studies demonstrate that pasteurization causes minimal changes to casein and limited whey protein denaturation, resulting in comparable allergic responses. In a clinical study of five children with confirmed cow's milk allergy, consumption of raw, pasteurized and homogenized/pasteurized milk all triggered significant and similar allergic reactions, indicating that pasteurization does not reduce milk allergenicity. ^{[53] [53]} Høst A, Samuelsson EG. Allergic reactions to raw, pasteurized, and homogenized/pasteurized cow milk: a comparison. A double-blind placebo-controlled study in milk allergic children. Allergy. Feb 1988;43(2):113-8. doi:10.1111/j.1398-9995.1988.tb00404.x, ^{[54] [54]} Poulsen OM, Hau J, Kollerup J. Effect of homogenization and pasteurization on the allergenicity of bovine milk analysed by a murine anaphylactic shock model. Clin Allergy. Sep 1987;17(5):449-58. doi:10.1111/j.1365-2222.1987.tb02039.x, ^{[55] [55]} McLaughlan P, Anderson KJ, Widdowson EM, Coombs RR. Effect of heat on the anaphylactic-sensitising capacity of cows' milk, gots' milk, and various infant formulae fed to guinea-pigs. Arch Dis Child. Mar 1981;56(3):165-71. doi:10.1136/adc.56.3.165

Likewise, proposed immune-related differences, such as those involving immunoglobulins, also lack evidence. Bovine milk contains low levels of immunoglobulins (0.6–1.0 mg/mL), which are physiologically negligible in humans when consumed directly. ^{[56] [56]} Hurley WL. Immunoglobulins in mammary secretions. vol Volume 1. Proteins. Part A. In P F Fox and P L H McSweeney (ed), Advanced Dairy Chemistry. Kluwer Academic/Plenum Publishers; 2003:422-447., ^{[57] [57]} Fox PF. Milk proteins: general and historical aspects. InAdvanced dairy chemistry—1 proteins: Part a/part B 2003 (pp. 1-48). Boston, MA: Springer US. Immunoglobulin G (IgG) comprises 85–90% of milk immunoglobulins and is largely heat-stable; LTLT pasteurization (145°F/63°C, 30 min) does not alter IgG levels, while HTST (162°F/72°C, 15 s) causes only ~1% denaturation. ^{[58] [58]} Mainer G, Sanchez L, Ena JM, Calvo M. Kinetic and thermodynamic parameters for heat denaturation of bovine milk IgG, IgA and IgM. Journal of Food Science. 1997 Sep;62(5):1034-8. To date, no controlled studies demonstrate improved immune outcomes from consuming these components from raw milk.

Recommendations from National and International Organizations

Nearly all major national and international health organizations strongly recommend consuming only pasteurized milk and dairy products. These organizations include the American Medical Association, American Academy of Pediatrics, American Veterinary Medical Association, International Association for Food Protection, National Environmental Health Association, American Public Health Association and the U.S. Food and Drug Administration. ^{[16] [16]} "Raw Milk Misconceptions and the Danger of Raw Milk Consumption." U.S. Food and Drug Administration, May 3, 2024. https://www.fda.gov/food/buy-store-serve-safe-food/raw-milk-misconceptions-and-danger-raw-milk-consumption., ^{[59] [59]} Berg, Sara. "Raw Milk: Questions Patients May Have and How to Answer." American Medical Association, December 30, 2024. https://www.ama-assn.org/public-health/prevention-wellness/raw-milk-questions-patients-may-have-and-how-answer., ^{[60] [60]} Committee on Infectious Diseases, Committee on Nutrition, Brady MT, Byington CL, Davies HD, Edwards KM, Glode MP, Jackson MA, Keyserling HL, Maldonado YA, Murray DL. Consumption of raw or unpasteurized milk and milk products by pregnant women and children. Pediatrics. 2014 Jan 1;133(1):175-9., ^{[61] [61]} "Raw Milk." American Veterinary Medical Association. n.d. https://www.avma.org/resources-tools/avma-policies/raw-milk., ^{[62] [62]} Schmidt RH, Davidson PM. Milk Pasteurization and the Consumption of Raw Milk: International Association for Food Protection (IAFP); n.d., ^{[63] [63]} "Policy Statement: Sale or Distribution of Raw Milk." National Environmental Health Association, July 2017. https://www.neha.org/Images/resources/NEHA_Policy_Statement_Raw_Milk_0.pdf., ^{[64] [64]} "Compulsory Pasteurization of All Non-Human-Derived Animal Milk Products Intended for Human Consumption." American Public Health Association, November 1, 2016. https://www.apha.org/policy-and-advocacy/public-health-policy-briefs/policy-database/2016/12/21/pasteurization-of-animal-milk. In 2012, the U.S. federal government rejected a petition seeking nationwide legalization of raw milk sales, citing scientific evidence supporting the public-health benefits of pasteurization. ^{[65] [65]} W, S. "Legalize Raw Milk Sales on a Federal Level." National Archives and Records Administration, September 23, 2011. https://petitions.obamawhitehouse.archives.gov/petition/legalize-raw-milk-sales-federal-level/.

Conclusion

Although raw milk is often promoted for its perceived nutritional, immunological or probiotic advantages, there are no controlled human studies to substantiate these claims. Pasteurization does not meaningfully alter the bioavailability of key nutrients, nor does it increase the allergenicity of milk proteins. Likewise, bacteria present in raw milk are not probiotic and frequently originate from the farm environment, infected udder tissues or fecal contamination rather than from human-associated beneficial strains. Evidence indicates raw milk continues to pose well-documented microbiological risks, with repeated outbreaks involving E. coli O157:H7, Campylobacter, Salmonella and Listeria, often resulting in severe illness particularly among children. Given the absence of proven health benefits and the persistence of preventable pathogen exposure, pasteurized milk remains the safer and more reliable option for public consumption.

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