Is Raw or Pasteurized Milk Better For Your Health?

Medically reviewed by Melissa Nieves, LNDMedically reviewed by Melissa Nieves, LND

Though milk consumption is declining, it continues to be an important source of calories and nutrients for millions of people worldwide.

Commercially sold milk is pasteurized or heat-treated to make it safe for consumption. However, some people prefer purchasing unpasteurized or raw milk, claiming it's better for health. Raw milk may offer some potential benefits, but it also has more health risks than pasteurized milk.

What Is Pasteurization?

Pasteurization is a process that uses heat to kill potentially harmful organisms found in milk.

French scientist Louis Pasteur first developed the pasteurization process in 1864, and pasteurized milk became commonplace in the United States in the early 1900s.

In the United States, the pasteurization process of milk usually involves heating chilled, raw milk between steel plates until it reaches 161 degrees Fahrenheit (72 degrees Celcius). The milk is held at that temperature for at least 15 seconds and then quickly cooled back to its original temperature of 39 degrees Fahrenheit (4 degrees Celcius).

This heating process kills microorganisms that are harmful to human health, including those that cause diseases like listeriosis, typhoid fever, Q fever, diphtheria, and brucellosis.

With the exception of products labeled as "raw," all milk sold in the U.S. is pasteurized.

Benefits of Pasteurized Milk

Pasteurization makes milk safer to drink. The heating process kills harmful organisms commonly found in raw milk, such as Salmonella, Listeria, and Staphylococcus species. These microorganisms cause disease in humans and cause milk to spoil faster.

Choosing pasteurized milk over raw milk can help prevent disease. According to the U.S. Food and Drug Administration (FDA), for every two billion servings of pasteurized milk or milk products consumed in the U.S., only one person will get sick.

Most milk in the U.S. is pasteurized using the 15-second method mentioned above, which is known as high temperature, short time (HTST) pasteurization. Another type of pasteurization is ultra-pasteurization (UP). This method involves heating milk to at least 280 degrees for at least two seconds.

UP is effective for killing pathogenic microorganisms and extending the shelf life of milk. However, this process is associated with negative flavor and color changes in milk. This higher-heat process is also linked to the formation of potentially harmful compounds called heterocyclic aromatic amines (HAAs), some of which are classified as carcinogens, substances that may increase cancer risk.

Nutritional Differences

There is no significant nutritional difference between raw and pasteurized milk.

The pasteurization process does result in small losses of certain nutrients, such as B12, vitamin E, vitamin C, folate, and riboflavin. However, these changes aren't considered significant and are unlikely to make a difference in health.

For example, raw milk is higher in vitamin C, a nutrient that acts as a powerful antioxidant in the body. However, dairy products aren't considered a primary source of vitamin C in the diet. While raw milk does contain a small amount of this nutrient, it's much lower than what's found in vitamin C-rich foods like fruits and vegetables.

Both raw and pasteurized milk are good sources of several essential nutrients, including protein, B vitamins, selenium, and calcium.

Potential Benefits of Raw Milk

Studies suggest that consuming raw milk may benefit several aspects of health.

For example, research shows that people who grow up drinking raw milk tend to be less likely to develop certain health conditions, such as asthma, allergies, and atopy, a genetic tendency to develop allergic diseases.

Scientists think this may be because people who grow up drinking raw milk are exposed to pathogens from a young age, which may build up their immune systems and protect them from developing immune-related conditions later in life.

One study involving 983 infants from rural areas of five European countries found that, compared to pasteurized milk, infants who consumed raw milk during the first year of life were about 30% less likely to develop respiratory tract infections and fever at 12 months of age. The infants fed raw milk were also less likely to develop rhinitis (congestion and stuffy nose) and ear infections. The study also found that the children who drank raw milk had lower levels of the inflammatory marker C-reactive protein (CRP).

The most significant benefits of raw milk consumption are associated with consumption early in life. This means starting to drink raw milk later in life may not offer the same benefits.

Research comparing the consumption of raw versus pasteurized milk is limited, so it's unclear if drinking raw milk over pasteurized milk offers other benefits.

Risks of Raw Milk

There are several risks associated with drinking raw milk. However, it's important to note that most cases of contamination of raw milk are associated with unsafe processing, storage, and transport conditions, not the milk itself.

Consuming raw milk that has been contaminated with pathogenic microorganisms such as Salmonella, E. coli, Campylobacter, Yersinia, Listeria, and S. aureus can cause severe symptoms, including diarrhea, vomiting, and stomach pain.

Certain groups are at a higher risk of developing a serious illness from these microorganisms, including:

• Children under the age of five

• Older adults

• People with weakened immune systems

• Pregnant people
  

From 1998-2018, there were 202 outbreaks related to drinking raw milk, which caused 2,645 illnesses and 228 hospitalizations. Ingesting certain microorganisms in raw milk, like Campylobacter species and E. Coli O157:H7, may trigger the development of serious diseases, such as Guillain-Barrés syndrome (an autoimmune disease) and hemolytic uremic syndrome (a blood disorder), both of which can be life-threatening.

Some experts argue not all raw milk is dangerous and that using safe methods to produce raw milk can significantly reduce the risk of contamination with potentially harmful microorganisms. However, the FDA still recommends drinking pasteurized milk due to raw milk's potential for higher contamination risk.

Pasteurized milk can still be contaminated with harmful microorganisms like Listeria, but the risk is much greater when drinking raw milk.

Every U.S. state has different laws regarding the sale of raw milk. For example, in New York, farmers are allowed to sell raw milk to consumers as long as they've obtained proper permits, while in New Jersey, the sale of raw milk is banned. Check your state's Department of Agriculture website for more information.

Shelf Life and Storage

Raw milk has a shorter shelf life than pasteurized milk. This is because the microorganisms in raw milk cause it to spoil faster.

The shelf-life of pasteurized milk can range from 12-21 days when stored at temperatures under 45 degrees. An ultra-pasteurized milk has a shelf-life between 30-90 days.

Though it's unclear how long raw milk can last under ideal storage temperatures, most raw milk suppliers suggest a shelf life of 7-14 days.

Keep pasteurized and raw milk refrigerated at all times to prevent spoilage.

Other Factors To Consider

Whether you're drinking raw or pasteurized milk, the nutritional composition and health benefits of the milk are impacted by several factors, including what the cows eat.

For example, studies show that milk from cows that consume grass-based diets is higher in beneficial fatty acids, such as conjugated linoleic acid and omega-3 fatty acids, compared to cows fed grain-based diets.

Organic and grass-fed milk has also been shown to contain higher levels of certain antioxidants, such as vitamin E and beta-carotene, which have anti-inflammatory and cellular-protective properties.

Is Raw or Pasteurized Better for Health?

Raw and pasteurized milk are nutritious and provide essential nutrients such as calcium, protein, and selenium. However, major health organizations, including the FDA, recommend consuming only pasteurized dairy products.

Raw milk has an increased risk of contamination with potentially harmful microorganisms, like Listeria, which can cause fever, headaches, flu-like symptoms, and even seizures. Listeria exposure is especially dangerous for pregnant people, as it can affect the health of the fetus.

A Quick Review

Most milk and dairy products in the U.S. are pasteurized, or heat-treated, to destroy certain harmful microorganisms found in raw milk. However, some people believe unpasteurized or raw milk is better for health.

Raw milk has a much higher risk of contamination from harmful bacteria than pasteurized milk, outweighing any potential benefit. There is also little nutritional difference between raw and pasteurized milk.

Health organizations recommend drinking pasteurized milk only and avoiding raw milk products to reduce your risk of contracting a foodborne illness.

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