Raw milk is milk that has not been pasteurized, meaning it goes straight from the animal to the bottle without being heated to kill bacteria. While most milk sold in grocery stores is pasteurized, raw milk has gained popularity among people who believe it offers superior nutrition or health benefits. The reality is more nuanced: raw milk does contain certain nutrients and enzymes that pasteurization reduces, but it also carries well-documented risks from dangerous bacteria.
How Raw Milk Differs From Store-Bought Milk
The key difference is heat treatment. Pasteurization heats milk to a high enough temperature, for a long enough time, to kill disease-causing germs. Raw milk skips this step entirely. Most commercial milk is also homogenized, a mechanical process that breaks fat globules into smaller particles so the cream doesn’t separate and rise to the top. Raw milk is typically sold unhomogenized, which is why it often has a visible cream layer.
In taste and texture, many raw milk drinkers describe it as richer and more complex than pasteurized milk. That cream layer can be shaken back in or skimmed off. The flavor varies by season, breed of cow, and what the animals eat, something that industrial processing standardizes out of conventional milk.
What’s Actually in Raw Milk
Raw milk contains the same basic nutritional profile as pasteurized milk: protein, fat, calcium, and a range of vitamins. The question people ask is whether pasteurization destroys important nutrients. A systematic review and meta-analysis looking at this question found that pasteurization does reduce levels of several vitamins, including B1, B2, C, and folate. Vitamin B12 and vitamin E also decreased after heat treatment, while vitamin A actually increased. Vitamin B6 levels showed no significant change.
These reductions sound concerning, but context matters. Milk is not a major dietary source of vitamin C or folate for most people. The B-vitamin losses are real but modest in the context of an overall diet. You’d get far more vitamin C from a single orange than from any amount of milk, raw or otherwise.
Raw milk also contains active enzymes that pasteurization destroys. One that gets a lot of attention is lactoperoxidase, which has genuine antimicrobial properties. It works by catalyzing chemical reactions that interfere with bacterial metabolism, essentially slowing bacterial growth in the milk itself. This is part of the cow’s own defense system for protecting the milk supply. However, lactoperoxidase faces a significant limitation as a health supplement: it breaks down in the digestive system. Researchers have noted that oral consumption of lactoperoxidase is challenged by degradation in the gut, and suggest it may be more useful in topical applications like wound care than as something you drink.
The Allergy and Asthma Connection
One of the most frequently cited benefits of raw milk is a potential protective effect against allergies and asthma, particularly in children. This claim has some epidemiological support. The GABRIELA study, a large European study designed specifically to investigate the biological components of farm milk, found that reported consumption of raw milk in early life was inversely related to atopy (allergic sensitivity), hay fever, and asthma in school-aged children.
There’s an important caveat here. These studies looked at children growing up on farms, where raw milk consumption is just one of many environmental differences. Farm children are exposed to a wider range of microbes from birth, spend more time outdoors, and have different diets overall. Researchers haven’t been able to fully separate the effect of raw milk from the broader “farm effect” on immune development. The association is interesting, but it doesn’t prove that buying raw milk at a market will protect a suburban child from allergies.
Raw Milk and Lactose Intolerance
A popular claim holds that people who can’t tolerate pasteurized milk can drink raw milk without problems, supposedly because raw milk contains bacteria that help digest lactose. A randomized controlled trial put this directly to the test. Sixteen adults with confirmed lactose malabsorption drank raw milk, pasteurized milk, and soy milk in random order over separate eight-day periods, gradually increasing the dose.
The results were clear: symptom severity was not different between raw and pasteurized milk at the highest dose. Breath hydrogen levels, the standard measure of lactose maldigestion, were actually higher with raw milk than pasteurized on the first day. By day eight, the two were identical. In short, raw milk offered no advantage for people with lactose intolerance.
Bacterial Contamination Risks
The reason pasteurization was invented in the first place is that raw milk can harbor dangerous bacteria. A systematic review covering two decades of U.S. data (2000 to 2019) found that raw bulk tank milk samples tested positive for harmful pathogens at notable rates: Campylobacter in about 6% of samples, Listeria and Shiga toxin-producing E. coli each in about 4.3%, and Salmonella in about 3.6%. These aren’t obscure organisms. Campylobacter causes severe diarrheal illness. Listeria can be fatal for pregnant women, newborns, and people with weakened immune systems. Shiga toxin-producing E. coli can cause kidney failure, particularly in young children.
The cumulative toll is significant. Between 1998 and 2018, the CDC documented 202 outbreaks linked to raw milk consumption in the United States, resulting in 2,645 illnesses and 228 hospitalizations. Given that raw milk represents a tiny fraction of total milk consumption, these numbers reflect a disproportionately high risk per serving compared to pasteurized milk.
Bird Flu and Raw Milk
A newer concern emerged in 2024 when H5N1 avian influenza was first identified in U.S. dairy cattle in Texas. The virus spread to herds across at least 12 states, with the actual number of affected farms likely much higher. Pasteurization makes contaminated milk safe to drink, but raw milk from an infected herd would not have that safeguard.
The disease has proven transmissible from cows to humans. Early cases in dairy workers involved eye infections, but a subsequent case showed respiratory symptoms like coughing, which raised concern because respiratory transmission is what would allow the virus to spread between people. At the time of detection, human-to-human transmission had not been confirmed, but the situation added a new dimension to the raw milk safety debate that didn’t exist a few years ago.
Legal Status Varies by State
Raw milk sales are legal in some form in many U.S. states, but the rules vary widely. Some states allow retail sales in stores, others permit only on-farm sales, and some ban the sale of raw milk entirely. Federal law prohibits selling raw milk across state lines for direct human consumption. In countries like Canada, Australia, and Scotland, raw milk sales are banned outright. Where it is sold legally, raw milk typically carries a warning label.
If you choose to drink raw milk, the risk profile is not evenly distributed. Young children, pregnant women, older adults, and anyone with a compromised immune system face the greatest danger from the pathogens raw milk can carry. For healthy adults, the risk per glass is low in absolute terms, but it’s measurably higher than the near-zero risk from pasteurized milk. The nutritional differences, while real, are small enough that they don’t offset the safety tradeoff for most people.