Since the domestication of cattle, , cow’s milk, a source of healthy fats, has been harnessed as an integral part of the human diet. Moreso, milk has shaped our gut health and the ability to digest foods around the world. However, prior to the introduction of pasteurization, these health benefits were also accompanied by significant risk. Historically speaking, milk consumption was often associated with , and it was not until the 1860s that began to change.

Pasteurization, the process of heat sterilizing food items to kill disease-causing microbes and slow spoilage, was widely adopted by public health organizations and food handlers by the 20th century. It is arguably one of the greatest public health triumphs to date as its implementation has significantly reduced the transmission of foodborne illness.

In spite of this public health and microbiological feat, the popularity of raw (unpasteurized) milk consumption has resurged and is an ongoing public health concern in the United States. According to , from 1998-2018, the U.S. Centers for Disease Control and Prevention (CDC) reported “more than 200 illness outbreaks traced to raw milk, which sickened more than 2,600 people and hospitalized more than 225." Still, raw milk consumption has been linked to false claims that make speculative assertions about its health benefits while downplaying the associated health risks. Here, we dive into the raw milk debate at the microbial level, exploring the risks, proposed benefits and overall impact on the human body.

Raw Milk Contaminants

Common Bacterial Pathogens in Raw Milk

Raw (unpasteurized) milk can harbor a variety of  Campylobacter jejuni and Listeria monocytogenes account for almost around the world. Mycobacterium bovis, Brucella and Salmonella are also common sources of raw milk contamination. These bacterial pathogens can cause serious illnesses, such as tuberculosis, brucellosis, listeriosis and typhoid fever. Bovine tuberculosis infection can lead to a persistent cough, chest pain, fever, night sweats, weight loss, fatigue and can become life-threatening without treatment. Brucellosis causes undulating fevers, chills, joint and muscle pain, headaches and profound fatigue. Infections can last weeks or even months and may relapse if not adequately treated. Meanwhile, Listeriosis poses a particular risk to pregnant individuals, newborns, the elderly and those with weakened immune systems. Symptoms include fever, muscle aches, nausea and diarrhea. Severe complications, such as meningitis or sepsis, can occur in vulnerable populations. Similarly, typhoid fever leads to sustained high fever, abdominal pain, headache and fatigue. Left untreated, typhoid fever can result in serious intestinal complications.

Raw Milk and Avian Flu

In February 2024, a strain of highly pathogenic avian influenza, H5N1 clade 2.3.4.4b was detected in dairy cows for the first time. While the incidence was first reported in Texas. —in one study, approximately 20% of pasteurized milk samples contained viral particle remnants. While no reports of raw milk-to-human transmission have been reported at the time of this writing, studies have shown that .

Amid a growing interest in the wider distribution and sale of raw milk in the U.S., the above findings about potential pathogens raise new concerns. While it remains unknown whether people can contract avian flu from raw milk, humans are susceptible to the disease, and there have been cases of humans contracting avian influenza after working with sick dairy cows. Fortunately, making pasteurized milk still the safest form of milk for consumption.

Sources of Raw Milk Contamination

It is important to note that raw milk contamination can and does occur even when the milk comes from healthy animals and is handled with care. This contamination risk has existed as long as humans have consumed animal milk. Common contamination can occur at the udder, via direct transmission from blood of cow into the milk (systemic infection), fecal contamination during milking or through dirty equipment. Populations at highest risk of serious health complications from raw milk contamination include elderly persons, children under 5 years old and pregnant women. Additionally, immunocompromised populations, or persons without a fully intact immune response, are at extreme risk of contracting milk-borne diseases from raw milk ingestion.

Raw Milk Can Be Sold Legally but Must Meet Strict Hygiene and Safety Standards

Raw milk can still be legally sold in different countries, but it must meet very stringent regulatory requirements. For example, the European Union mandates that raw milk for sale must meet several hygiene and safety standards. These stringent regulations, which address equipment cleanliness, animal health and proper milk storage and handling, help to reduce incidence of disease outbreaks but cannot completely ablate the risk of severe disease. This is due, in part, to factors (both intrinsic and extrinsic) that make testing raw milk batches difficult (e.g., bacteria spores not evenly distributed in milk samples, low inoculum levels at timing of sampling and insufficient daily monitoring of raw milk).

The specific hygiene rules ( and ) for food of animal origin, which are highlighted below, were established on April, 9, 2004 by the European Parliament and the Council of the European Union.

• Milking Hygiene: Equipment and facilities must be clean and inspected.
• Animal Health: Animals must be free from brucellosis and tuberculosis.
• Bacterial Standards: Raw milk must meet limits on total bacterial count and somatic cell count.
• Cooling Requirements: Milk must be cooled to ≤ 6°C (41°F) immediately after milking and maintained at that temp.
• Labeling: Often required to state "Raw milk—boil before consumption" or similar warning.
• Traceability: Farmers and sellers must be able to trace milk back to the source herd.

Debunking Purported Health Benefits of Raw Milk

Despite known health risks, and the fact that pasteurization offers an extremely safe and effective way to avoid them, raw milk advocates cite an array of false health benefits associated with consuming untreated dairy products, including the proposal that raw milk possesses superior nutrients, beneficial enzymes and vitamins; possesses the potential to reduce the risk of allergy and asthma in children; and undergoes reduced processing. As a result of this circulated misinformation, raw milk popularity has seen a resurgence in the U.S. However, several of these claims have been “demystified” or outright refuted by .

Vitamins and Nutrients

• Claim: Raw milk retains beneficial enzymes and vitamins.
• Public Health Take-Away: Pasteurization slightly reduces some nutrients, but, overall, milk remains highly nutritious; key nutrients like calcium and protein are unaffected.

Raw milk advocates have raised concerns about the impact of pasteurization on the nutritional content of milk. One  addressed the claim that pasteurization strips milk of its vitamins and other nutrients. Scientists conducted a systematic review and meta-analysis of 40 other studies evaluating the impact of pasteurization on vitamin content (A, B1, B2, B6, B12, C, E and folate) and found that some vitamin levels were modestly diminished. However, the effect of pasteurization on the nutritive value of milk was nominal, as many of these vitamins are naturally found at relatively low levels in milk to begin with and are primarily maintained through consumption of other food groups. Additionally, repeat testing has demonstrated that  and are not altered during the pasteurization process, further debunking this claim.

Probiotics

• Claim: Raw milk has natural probiotics good for gut health.
• Public Health Take-Away: Pasteurization does kill natural bacteria, but it also eliminates harmful pathogens; probiotics can be added safely through fermented dairy (e.g., yogurt).

Mitigating Allergies and Asthma

• Claim: Raw milk is better tolerated by lactose-intolerant people.
• Public Health Take-Away: There is no conclusive evidence to support this claim: many lactose-intolerant people react to both raw and pasteurized milk. Lactose-free milk is a safer option.
• Claim: Raw milk may reduce the risk of allergies and asthma in children.
• Public Health Take-Away: Some observational studies suggest links, but findings are not strong enough for health policy; raw milk carries infection risks.

Consuming raw milk does not in itself cure or treat asthma or allergies, as these conditions have complex underlying causes. However, consumption of farm milk (milk sold directly to consumers from small farms) does appear to coincide with reduced incidence of asthma and allergies in farm workers and rural farmland communities. In a commonly mis-cited study by , also known as the PARSIFAL study, scientists found an inverse association of farm milk consumption, not raw milk consumption, with asthma and allergy incidence. In reality, about half of the farm milk consumed during the study was boiled. The study’s authors explicitly stated in their conclusion that “raw milk may contain pathogens such as Salmonella or EHEC [Enterohemorrhagic E. coli], and its consumption may therefore imply serious health risk...consumption of raw farm milk cannot be recommended as a preventive measure.” It is still unclear exactly why farmland communities seem to have lower levels of allergies and reduced asthma; this can be investigated further both in the context of early environmental exposure to an array of microbes throughout childhood development and in raw milk consumption.

Natural vs. Processed

• Claim: ​⿒‹â¿’‹â€‹â€‹â¿’‹â¿’‹More “natural” and less processed.
• Public Health Take-Away: Pasteurization is a basic safety step, not heavy processing; it prevents serious diseases like listeriosis and salmonellosis.
• Claim: Industrial dairy practices are unsafe/unhealthy.
• Public Health Take-Away: Food safety systems ensure milk is tested, monitored and pasteurized to prevent outbreaks. Raw milk can vary widely in quality.

Pasteurization, named after the French scientist Louis Pasteur, who developed the procedure in the 1860s, has significantly reduced the transmission of milk-borne diseases and, ultimately, saved many lives by clearing harmful microbes from food and beverages. Pasteurization is a physical process. No chemical preservatives, additives or treatments are used during pasteurization. The only input is heat, followed by rapid cooling. Specifically, it involves heating milk to a high temperature (145-280°F) for a set amount of time (30 minutes-2 seconds), depending on the , to kill potentially harmful bacteria. Today, food regulatory review, which implements pasteurization for dairy products to be sold in different countries, including the U.S., significantly reduces milk-associated illness. On the other hand, the consumption of raw milk leaves consumers at a higher risk of contracting preventable foodborne illness. Dairy product consumption accounts for about 1% of reported foodborne illness in the U.S., and approximately . Thus, the drinking pasteurized milk to mitigate the risk of contracting known diseases.

Anecdotal evidence about proported health benefits (e.g., energy, immunity, etc.) is not scientifically validated; such benefits may be placebo effect or unrelated to raw milk consumption.

The Raw Milk Take Home Message

Raw milk consumption is broadly understood to pose a significant public health risk as it introduces the consumer to harmful and potentially life threatening bacterial and viral pathogens. This fundamental risk far outweighs any alleged health benefits, many of which are only anecdotally supported and not backed by scientific evidence. In fact, some raw milk health claims are outright misleading, not true or taken out of context, and can put people in danger. 바카라 is clear that the implementation of milk pasteurization has been a critical tool in keeping us safe from harmful microbes while utilizing helpful microbes to better our gut health. The manipulation of microbes on and in our food sources, including milk, has allowed us to harness a positive relationship with the microbial world to benefit human health.

While we understand these facts to be true and based on scientific evidence, the current debate on raw milk, fueled by the spread of misinformation, makes it clear that we need to better communicate the value of food regulation and pasteurization to the public. If we cannot communicate this foundational scientific understanding clearly and succinctly, we risk losing the key aspect for successful implementation of public health safety in food regulatory oversight: trust.

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