Raw Milk: Do Its Benefits Outweigh the Dangers?

Raw milk is often seen as a natural alternative to pasteurized milk. While it may contain more antimicrobials, the health claims surrounding it are not well-supported by evidence. The potential risks, such as severe infections from harmful bacteria, cannot be overlooked. Milk is a nutritious food that provides essential protein, vitamins, minerals, and fatty acids. Before pasteurization became common in the early to mid-1900s, all milk was consumed raw. Today, as people seek natural, locally sourced foods, the consumption of raw milk is on the rise.

What is Raw Milk?

Raw milk is milk that has not been pasteurized or homogenized. It primarily comes from cows but can also be sourced from goats, sheep, buffalo, or even camels. This type of milk can be used to make various products, including cheese, yogurt, and ice cream. Interestingly, only about 1% of Americans regularly drink raw milk.

The Pasteurization Process

Pasteurization is a process that involves heating milk to kill harmful bacteria, yeasts, and molds. This process also extends the product's shelf life. The most common method in the U.S. today is High Temperature Short Time (HTST) pasteurization, which heats milk to at least 161°F for 15 seconds. Another method, used globally, heats raw milk to 145°F (63°C) for 30 minutes. Ultra-heat treatment (UHT) heats milk to 275°F (135°C) for a few seconds, allowing it to be consumed in some European countries.

The HTST method keeps milk fresh for 2–3 weeks, while UHT extends the shelf life up to 9 months. Pasteurized milk is often homogenized, a process that applies extreme pressure to disperse fatty acids evenly, enhancing appearance and taste.

Summary

Raw milk has not been pasteurized or homogenized. Pasteurization heats milk to kill bacteria and increases shelf life.

Common Claims About the Benefits of Raw Milk

Advocates of raw milk argue that it is a complete, natural food containing more amino acids, antimicrobials, vitamins, minerals, and fatty acids than its pasteurized counterpart. They also claim it is a better choice for individuals with lactose intolerance, asthma, and autoimmune and allergic conditions.

Pasteurization was introduced in response to a bovine tuberculosis epidemic in the early 1900s, which resulted in an estimated 65,000 deaths over 25 years due to contaminated dairy. Bovine tuberculosis can easily be transmitted to humans and remains a concern in areas where unpasteurized milk is consumed. Some raw milk proponents argue that the harmful bacteria eliminated by pasteurization are no longer a threat and that pasteurization is unnecessary. They also claim that the heating process during pasteurization diminishes the overall nutrition and health benefits of milk. However, most of these claims lack scientific backing.

Claim 1: Pasteurized Milk Has Fewer Nutrients

Pasteurizing milk does not significantly reduce its vitamin, carbohydrate, mineral, or fat content. An extensive meta-analysis of 40 studies found only minor losses of the water-soluble vitamins B1, B6, B9, B12, and C. Given the already low levels of these nutrients in milk, these losses are insignificant. Additionally, these vitamins are abundant in many fruits, vegetables, and whole grains, making it easy to compensate for any losses in your diet.

Levels of fat-soluble vitamins A, D, E, and K also minimally decrease during pasteurization. Milk is high in calcium and phosphorus, both essential for healthy bones, cell function, muscle health, and metabolism. These minerals are heat-stable, with one cup of pasteurized milk providing 23% of the Daily Value (DV) for calcium and nearly 20% of the DV for phosphorus.

Claim 2: Pasteurizing Milk Reduces Fatty Acids

Studies have shown no significant differences in the fatty acid profiles of raw and pasteurized milk. In fact, pasteurization may enhance the digestibility of fatty acids. One study collected 12 samples of cow's milk from a single dairy factory, dividing them into raw, pasteurized, and UHT-treated groups. Comparisons revealed no significant differences in major nutrients or fatty acids among the three groups.

Claim 3: Pasteurizing Milk Destroys Proteins

One cup (245 grams) of pasteurized milk contains 8.26 grams of protein. Approximately 80% of milk protein is casein, while the remaining 20% is whey. These proteins can aid in muscle growth and improve insulin resistance. Pasteurization does not reduce casein levels, as this protein is heat-stable. While whey protein is more susceptible to heat damage, pasteurization appears to have minimal impact on its digestibility and nutritional composition.

A 2008 study involving 25 healthy individuals who consumed raw, pasteurized, or UHT milk for a week found that the proteins from pasteurized milk had the same biological activity in the body as those from raw milk. Interestingly, milk exposed to ultra-high temperatures (275°F or 135°C for a few seconds) increased protein nitrogen uptake by about 8%, indicating better utilization by the body.

Claim 4: Raw Milk Protects Against Allergies and Asthma

A milk protein allergy affects 2–3% of children in developed countries during their first year of life, with 80–90% of cases resolving spontaneously by age 6. Raw milk contains components that may influence immune function. A 2020 meta-analysis linked raw milk consumption in children to a lower rate of asthma and allergic rhinitis (hay fever). Ongoing research is exploring the protective effects of “microbiologically safe,” minimally processed milk compared to pasteurized milk.

A study involving 983 infants in Europe found that raw milk consumption reduced the risk of respiratory infections and fever by 30%. However, it is crucial to note that these studies indicate an associated risk reduction rather than a direct correlation. Increased exposure to microbes in farming environments may also contribute to a reduced risk of asthma and allergies, potentially explaining some of these findings.

Claim 5: Raw Milk is Better for People with Lactose Intolerance

Lactose is a sugar found in milk, digested by the enzyme lactase produced in the small intestine. Some individuals do not produce enough lactase, leading to undigested lactose fermenting in the bowel, causing bloating, cramps, and diarrhea. Both raw and pasteurized milk contain similar amounts of lactose. However, raw milk contains the lactase-producing bacteria Lactobacillus, which is destroyed during pasteurization. This could theoretically improve lactose digestion for raw milk drinkers.

In a blind study, 16 adults with self-reported lactose intolerance consumed raw, pasteurized, or soy milk over three 8-day periods, separated by one-week washout periods. No differences were found in digestive symptoms between raw and pasteurized milk.

Claim 6: Raw Milk Contains More Antimicrobials

Milk is rich in antimicrobials, including lactoferrin, immunoglobulin, lysozyme, lactoperoxidase, bacteriocins, oligosaccharides, and xanthine oxidase, which help control harmful microbes and delay spoilage. However, their activity decreases when milk is refrigerated, regardless of whether it is raw or pasteurized. Pasteurization reduces lactoperoxidase activity by about 30%, but other antimicrobials remain mostly unchanged.

Summary

Claims that raw milk is more nutritious than pasteurized milk and a better choice for those with lactose intolerance, asthma, and autoimmune and allergic conditions have been shown to have little or no truth to them.

What Are the Dangers of Drinking Raw Milk?

Due to its neutral pH and high nutritional and water content, milk is an ideal breeding ground for bacteria. Milk originates from a sterile environment within the animal, but contamination can occur from the moment the animal is milked. Contaminants can come from the udder, skin, feces, milking equipment, handling, and storage. These contaminants are often invisible and may not be detectable until they proliferate.

Most harmful bacteria are eliminated during pasteurization. Those that survive typically do so in a damaged, non-viable form. Studies indicate that raw milk contains significantly higher levels of harmful bacteria than pasteurized milk. Keeping milk refrigerated helps suppress bacterial growth, regardless of whether it is raw or pasteurized.

Bacteria and Symptoms

Harmful bacteria that may be present in milk include Campylobacter, Salmonella, Escherichia coli (E. coli), Coxiella burnetti, Cryptosporidium, Yersinia enterocolitica, Staph aureus, and Listeria monocytogenes. Symptoms of infection are similar to those of other foodborne illnesses and may include vomiting, diarrhea, dehydration, headaches, abdominal pain, nausea, and fever. These bacteria can also lead to severe conditions such as Guillain-Barre syndrome, hemolytic uremic syndrome, miscarriage, reactive arthritis, chronic inflammatory conditions, and, in rare cases, death.

Who is Most at Risk?

Any person consuming milk that contains harmful bacteria is at risk. However, the risk is higher for pregnant individuals, children, older adults, and those with weakened immune systems. More than half of all disease outbreaks associated with raw milk have involved at least one child under age 5.

Severity of Raw Milk Outbreaks

A foodborne outbreak occurs when two or more reports of illness arise from consuming a common food. Between 1993 and 2006, 60% of the 4,413 reports of dairy-related illnesses (121 outbreaks) in the United States were linked to raw dairy products, including milk and cheese. Among milk-only outbreaks, 82% were from raw milk, compared to 18% from pasteurized milk.

During this period, two deaths from raw dairy and one from pasteurized dairy were reported, with three additional deaths since then. Those infected by raw milk were 13 times more likely to require hospitalization than those consuming pasteurized milk. Given that only 3–4% of the U.S. population drinks raw milk, the rates of related outbreaks, hospitalizations, and deaths are alarmingly high. More recent data indicates that raw milk or cheese causes 840 times more illnesses and 45 times more hospitalizations than pasteurized dairy.

Currently, many countries, including Australia, Canada, and Scotland, ban raw milk for human consumption. It is prohibited in 20 U.S. states, while others restrict its sales. Additionally, raw milk cannot be sold across state lines. However, the number of outbreaks is increasing, particularly in states that have legalized its sale.

Summary

Raw milk can harbor harmful bacteria that may lead to serious illness, especially in pregnant individuals, children, older adults, and those with compromised immune systems. Infections from raw milk are more frequent and severe than those caused by pasteurized sources.