The debate over raw milk vs pasteurized milk has been heating up in recent years, with passionate advocates on both sides. Raw milk enthusiasts often praise it as a “natural” superfood, while health experts raise concerns about its safety—including the risk of contamination by harmful bacteria and even viruses like bird flu. As a registered dietitian, I’m frequently asked about the nutritional value, purported health benefits, and risks of raw milk. In this guide, we’ll dive into the scientific evidence behind raw milk vs pasteurized milk—exploring their differences, nutritional profiles, health claims, and safety concerns—so you can make an informed decision about what’s in your glass.

raw milk vs pasteurized milk

Raw milk vs pasteurized milk: what’s the difference?

What is raw milk?

Raw milk is milk obtained directly from animals, such as cows, goats, or sheep, that is consumed without undergoing any heat treatment or processing. It contains all its natural components, including proteins, fats, carbohydrates, vitamins, minerals, and naturally occurring bacteria and enzymes. Supporters often highlight its perceived “natural” and “wholesome” qualities, marketing it as a purer alternative to pasteurized milk.

However, while raw milk’s lack of processing may seem like a benefit to some, it actually makes it vulnerable to harmful bacteria that can pose serious health risks. These pathogens can originate from multiple sources, including direct contact with animal feces, contamination from the cow’s udder or teats, unsanitary milking equipment, or environmental factors like dust, soil, or contaminated water. Without heat treatment to eliminate these microorganisms, raw milk remains untreated, allowing dangerous pathogens like Salmonella, E. coli, Listeria monocytogenes, and Campylobacter to survive and thrive.

raw milk vs pasteurized milk

What is pasteurized milk?

Pasteurized milk is raw milk that has been heat-treated to destroy dangerous bacteria while maintaining its nutritional integrity. While all milk—raw or pasteurized—can become contaminated during milking or handling, pasteurization eliminates these pathogens, making the milk significantly safer to consume.

Pasteurization was first introduced in the 19th century as a public health measure to reduce the incidence of foodborne illnesses. The process involves heating milk to a specific temperature for a short time to kill harmful microorganisms without compromising its nutritional value. Since then, it has become a global standard for ensuring milk safety, drastically reducing the risks associated with contamination while preserving essential nutrients like protein, calcium, and vitamins.

How do you pasteurize milk?

Pasteurization is the process of heating raw milk to a specific temperature for a set duration to eliminate harmful bacteria. Invented in the 19th century by French scientist Louis Pasteur, it was first used for wine and beer to prevent spoilage. Pasteur’s discovery that heat could destroy harmful microorganisms without altering taste or nutrition quickly expanded to milk, tackling deadly diseases like tuberculosis and brucellosis, once commonly spread through raw dairy.

In fact, before World War II, raw milk was a significant public health risk, with about 25% of all foodborne illnesses in the U.S. linked to dairy. However, the post-war boom in technology and infrastructure made pasteurization more accessible and widely adopted, transforming milk from a potential hazard to a staple of safe nutrition in American households.

Today, the most common pasteurization method is High-Temperature, Short-Time (HTST). By heating milk to 161°F (72°C) for just 15 seconds and then rapidly cooling it, this method wipes out harmful bacteria like E. coli, Salmonella, and Listeria, as well as viruses, including the H5N1 avian influenza virus (aka bird flu), while preserving the good stuff—protein, calcium, etc.

Considered one of the greatest public health achievements of all time, pasteurization didn’t just save lives—it made dairy a trustworthy source of nutrition for generations. Other methods, like Ultra-High Temperature (UHT), are also used, especially for shelf-stable milk products.

Nutritional comparison: is raw milk healthier than pasteurized milk?

There’s a common belief that raw milk is more nutritious than pasteurized milk, with claims that pasteurization ‘destroys’ essential nutrients. Let’s take a closer look at the nutritional profiles of raw milk vs pasteurized milk to separate fact from myth.

Raw milk nutrition facts

Per cup (8 oz) of whole raw milk:

  • Calories: 150
  • Protein: 8g
  • Fat: 8g
  • Carbohydrates: 12g
  • Calcium: 300mg
  • Vitamin A: 5% DV
  • Vitamin D: Naturally variable

Pasteurized milk nutrition facts

Per cup (8 oz) of whole pasteurized milk:

  • Calories: 150
  • Protein: 8g
  • Fat: 8g
  • Carbohydrates: 12g
  • Calcium: 300mg
  • Vitamin A: 5% DV
  • Vitamin D: 15% DV (fortified)

As you can see, pasteurization has minimal impact on milk’s nutritional content. Calcium levels are unaffected, and the macronutrient content—protein, fat, carbohydrates, and calories—also remains unchanged, ensuring that milk continues to provide its core nutritional benefits.

A meta-analysis of 40 studies found minor losses in some heat-sensitive vitamins, such as B vitamins, vitamin C, and folate, during pasteurization. However, milk isn’t a significant source of vitamin C or folate to begin with, and we typically get these nutrients from other dietary sources. No one’s drinking milk for the vitamin C, and the B vitamins remain present in amounts that still make pasteurized milk a good source.

Additionally, in the U.S., pasteurized milk is typically fortified with vitamin D, making it a powerhouse for this essential nutrient—something raw milk lacks, as it contains only trace amounts of vitamin D.

raw milk vs pasteurized milk

Benefits of raw milk: separating myth from fact

The debate over raw milk vs pasteurized milk often sparks passionate arguments, with raw milk advocates touting numerous health benefits ranging from improved digestion to curing allergies. But how much of this is backed by science, and how much is rooted in myth?

Myth 1: raw milk cures lactose intolerance

Raw milk advocates often claim it’s easier to digest for people with lactose intolerance because it contains bacteria that produce lactase—the enzyme needed to digest lactose. However, the truth is that the amount of lactase-producing bacteria in raw milk is too low to produce enough lactase to alleviate lactose intolerance symptoms, and refrigeration further reduces their lactase-producing activity. All milk, whether raw or pasteurized, contains lactose and can trigger symptoms in individuals with lactose intolerance. Period.

A small pilot study helped debunk this myth, finding no difference between raw and pasteurized milk in reducing lactose malabsorption or symptoms like bloating, gas, and discomfort. Both caused similar levels of digestive distress.

For those with lactose intolerance, yogurt (pasteurized, of course) is a far better dairy option. During yogurt production, specific lactase-producing bacteria, such as Lactobacillus bulgaricus and Streptococcus thermophilus, are added to milk to initiate fermentation. These bacteria not only break down a significant portion of lactose during production but also continue to actively digest lactose in the small intestine. Research shows that these bacterial cultures survive stomach acidity, and their lactase activity within the small intestine efficiently hydrolyzes lactose, reducing symptoms such as bloating and gas. This dual mechanism makes yogurt a more reliable and well-tolerated choice for lactose-intolerant individuals compared to milk​.

Bottom Line: Raw milk doesn’t cure or alleviate lactose intolerance. It contains lactose just like pasteurized milk and can trigger the same digestive symptoms. If you’re lactose intolerant, opt for yogurt or kefir made with pasteurized milk—they contain beneficial bacteria that actively help break down lactose.

Myth 2: raw milk boosts the immune system

Raw milk advocates often argue that it boosts the immune system thanks to its natural immunoglobulins and antibodies. While it’s true that raw milk contains some immunoglobulins, like IgG, these are primarily designed to protect calves by targeting bovine-specific pathogens—not to supercharge human immunity. Plus, the harsh, acidic environment of the human stomach breaks down most of these proteins long before they can make any real impact on your immune system. So, while it sounds impressive, the science doesn’t back up this claim.

Regardless, pasteurization has minimal impact on IgG levels, meaning any potential immune-related benefits of raw milk are largely preserved in pasteurized milk—without the serious risk of foodborne illnesses like E. coli, Listeria, and Salmonella. Far from “boosting” the immune system, raw milk is more likely to pose a threat to it, especially for vulnerable groups like children, pregnant individuals, and the elderly, who are at higher risk of severe and even life-threatening infections from contaminated dairy.

Bottom Line: Raw milk doesn’t “boost” the immune system. While it does contain small amounts of immune-related proteins, these are unlikely to have a significant effect on human immunity. The risk of harmful pathogens, however, poses a serious threat, especially to vulnerable populations.

Myth 3: raw milk can cure allergies and asthma

Raw milk enthusiasts often claim it can cure or prevent allergies and asthma, pointing to studies that suggest lower rates of these conditions among those who consume raw or farm milk. But when you dig into the research behind these claims, the story becomes far less convincing.

Some European observational studies have found a connection between farm milk consumption and reduced rates of asthma and allergies. However, these findings come with a big asterisk: the “farm effect.” Kids raised on farms experience unique factors—regular exposure to animals, the outdoors, and diverse microbes—all of which independently lower the risk of asthma and allergies. Even when researchers try to control for these variables, it’s nearly impossible to tease out the specific role of raw milk.

Another wrinkle is that much of this research compares raw or farm milk to ultra-high-temperature (UHT) treated milk, which is common in Europe. UHT milk undergoes intense heat processing that significantly alters its proteins, making these studies irrelevant to the U.S., where pasteurization is far milder.

Adding to the confusion, some studies lump boiled farm milk and raw milk together as if they’re interchangeable. For instance, the widely cited PARSIFAL study reported that about half of the farm milk consumed by participants was boiled—a process far more intense than pasteurization. The study’s authors made it clear their results couldn’t differentiate between the effects of raw and pasteurized milk and explicitly warned against raw milk due to the serious risks of pathogens like Salmonella.

From a scientific standpoint, there’s no compelling mechanism to explain why raw milk would prevent allergies or asthma. Mild pasteurization minimally alters milk proteins, so pasteurized milk’s allergenic properties are not significantly different from raw milk. For those with a true milk allergy, raw milk offers no safe alternative—it contains the same allergens.

Some researchers have speculated that components of whey protein might have protective effects against asthma, but these proteins aren’t unique to raw milk. Pasteurization doesn’t destroy them, meaning any potential benefit would still be present in pasteurized milk.

Bottom Line: Although some epidemiological data from farm settings suggests a link between milk consumption and lower rates of allergies and asthma, other factors from farm life, like regular exposure to animals and diverse microbes, are far more likely responsible. There’s no direct evidence that raw milk itself plays any “protective” role in preventing these conditions.

Myth 4: raw milk provides probiotics

Some raw milk advocates love to call it a “natural source of probiotics,” but here’s the deal: this claim doesn’t hold water (or milk, for that matter). While raw milk does contain live bacteria, it doesn’t meet the scientific definition of probiotics—specific microorganisms that, in adequate amounts, provide proven health benefits. Simply put, raw milk isn’t the probiotic powerhouse it’s cracked up to be.

For starters, the bacteria in raw milk are a chaotic mix from all kinds of sources—udder surfaces, soil, milking equipment, and yes, even feces. This randomness means raw milk’s microbes are more of a microbial lottery than a well-defined health product. Beneficial lactic acid bacteria? Sure, they’re there, but in such small quantities that they don’t make a meaningful difference. And here’s the kicker: while Bifidobacteria are well-known as beneficial probiotic bacteria in the right context, their presence in raw milk isn’t a good thing. In this case, it more likely indicates fecal contamination—since these bacteria are typically found in the cow’s gastrointestinal tract—and therefore signals poor farm hygiene, not probiotic potential.

And then there’s the elephant in the room: safety. Probiotics are supposed to promote health, but raw milk comes with serious risks, including pathogens like E. coli and Salmonella. These can cause severe illnesses, particularly in vulnerable groups like children. If you’re looking for a safe and effective way to boost your gut health, pasteurized fermented products like yogurt or kefir with added live cultures are the way to go. Raw milk may seem like a charming nod to the past, but when it comes to probiotics, it’s more of a gamble than a health benefit.

Bottom Line: Raw milk is not a reliable source of probiotics. Its bacteria are unpredictable and can include harmful pathogens, making pasteurized fermented products like yogurt or kefir a safer and more effective choice.

raw milk vs pasteurized milk

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Health risks of raw milk consumption

The debate over raw milk vs pasteurized milk is heated, but the risks of raw milk are impossible to overlook. Advocates of raw milk often describe it as “natural” and “wholesome,” but there’s nothing wholesome about the serious safety risks it carries. Contamination can occur at any stage—during milking, storage, or handling—and without pasteurization, harmful microorganisms like Salmonella, E. coli, Listeria monocytogenes, and Campylobacter can thrive. Pasteurization is the critical safety step that eliminates these dangerous pathogens, and skipping it leaves raw milk wide open to contamination. From dangerous pathogens to serious illnesses, consuming raw milk comes with hazards that far outweigh its supposed benefits.

Raw milk risks: what the numbers don’t show

Proponents of raw milk often claim its health risks are overblown, pointing to the relatively small number of reported outbreaks compared to other foodborne illnesses. From 1998 to 2018, the CDC documented 202 outbreaks linked to raw milk, resulting in 2,645 illnesses and 228 hospitalizations. At first glance, these numbers might seem insignificant, especially when compared to more commonly consumed foods. But here’s the real story: these figures barely scratch the surface. The CDC stresses that most foodborne illnesses go unrecognized, and for every reported case, countless others are never diagnosed or recorded.

In reality, unpasteurized dairy products are far riskier than the numbers suggest. A study from the CDC estimates they are 840 times more likely to cause foodborne illness and 45 times more likely to result in hospitalization compared to pasteurized dairy. This disparity exists because illness surveillance is largely passive—it depends on people seeking medical care, receiving an accurate diagnosis, and having the case formally reported. As a result, the true scale of raw milk-related illnesses is likely much higher.

Unlike pasteurized milk, which undergoes heat treatment to kill harmful bacteria, raw milk skips this critical safety step, leaving it vulnerable to contamination. Pathogens like Salmonella, E. coli, Listeria monocytogenes, and Campylobacter thrive in raw milk and are notorious for causing severe health issues, from gut-wrenching food poisoning to life-threatening complications like kidney failure and death. These risks make raw milk a gamble that isn’t worth taking.

High-risk groups: should you avoid raw milk?

While raw milk poses risks for everyone, some groups face much higher stakes. Young children, pregnant women, the elderly, and those with compromised immune systems are particularly vulnerable to the pathogens lurking in unpasteurized milk. These bacteria, like Listeria and E. coli, don’t just cause an upset stomach—they can lead to life-threatening complications like kidney failure, meningitis, and miscarriage.

In one analysis, children under the age of 19 accounted for nearly half of the illnesses linked to raw milk between 2013 and 2018, highlighting just how much harm it can cause to the youngest among us. Pregnant women and their unborn babies are at extreme risk, as Listeria infections can result in miscarriage or stillbirth. For kids under five, even one exposure to contaminated milk can lead to long-term health issues. For these groups, the risks of raw milk aren’t just theoretical—they’re potentially life-altering.

The takeaway? Raw milk is a risky choice for everyone, and health experts recommend avoiding it entirely. But for high-risk groups—pregnant individuals, young children, the elderly, and those with weakened immune systems—it’s downright dangerous and should be off the menu, period.

Bird flu virus: raw milk concerns

Recent findings have raised serious concerns about the potential risks of bird flu in raw milk. In November 2024, California health officials identified genetic material from the H5N1 avian influenza virus in unpasteurized milk from a Fresno dairy farm, prompting recalls and halting its distribution. This discovery highlights how raw milk can be a vehicle for viral contamination, particularly during outbreaks affecting livestock.

Bird flu, or avian influenza, can find its way into raw milk through infected animals or contaminated farm environments. Although there have been no confirmed cases of humans contracting the virus from consuming raw milk, its detection in unpasteurized dairy products emphasizes the critical role of pasteurization. This process not only eliminates harmful bacteria but also neutralizes viruses like bird flu, making pasteurized milk the safest choice for consumers.

The recent detection of the virus in raw milk serves as an urgent reminder of why pasteurization is essential—not just to prevent bacterial illnesses but also to guard against evolving viral threats.

Raw milk regulations—is raw milk illegal?

The legality of raw milk in the United States is a complex patchwork, with each state setting its own rules. Some states ban raw milk sales outright, while others allow it under specific conditions like farm-direct sales or cow-share programs. A few states even permit retail sales in grocery stores. Federal law, however, prohibits the interstate sale or distribution of raw milk, reflecting nationwide concern over its safety.

Public health data makes one thing clear: states with fewer restrictions on raw milk experience significantly more foodborne outbreaks. From 2013 to 2018, states with legal raw milk sales reported three times as many outbreaks as those where sales were prohibited. Worse, states that allowed retail sales saw even higher rates of illness compared to states limiting sales to on-farm purchases.

The connection is undeniable: looser regulations lead to more illnesses. Each time restrictions are relaxed, more people get sick, underscoring the serious risks raw milk poses. While it may be legal in some states, public health experts, including the CDC and FDA, strongly advise against consuming raw milk. Keeping strict regulations in place is crucial to protecting communities and preventing avoidable illnesses.

raw milk vs pasteurized milk state regulations

Key takeaways: a dietitian’s perspective

While raw milk is often marketed as “natural,” it poses significant risks due to harmful pathogens that pasteurization effectively eliminates.

Pasteurized milk provides the same essential nutrients—calcium, protein, and fortified vitamin D—without the health gamble. Public health data shows that stricter regulations on raw milk reduce outbreaks and illnesses, reinforcing the importance of these protections.

The bottom line on the raw milk vs pasteurized milk debate: pasteurized milk is the safer, smarter choice for everyone. For added health benefits like probiotics, choose pasteurized options like yogurt or kefir instead of taking unnecessary risks with raw milk.