Raw milk is milk that has not undergone pasteurization, the bacteria-killing heat treatment designed to reduce human pathogens and increase shelf life. Unpasteurized milk can contain potentially harmful and deadly pathogens, including listeria, salmonella, E. coli 0157:H7 and campylobacter.
Children, the elderly, pregnant women and people with weakened immune systems have the highest risk of contracting illness from these pathogens. According to the Centers for Disease Control, outbreaks associated with these pathogens are 2.2 times higher in states where raw milk sales are legal.
So why do people go so crazy for raw milk? They do so because of the supposed health benefits, which include improved immunity, allergy relief and gastrointestinal health.
One claim is that raw milk can improve digestive health and does not cause lactose intolerance. Yet research has failed to support the notion that there are levels of probiotics in raw milk to produce digestive benefits. Additionally, milk, whether raw or pasteurized, does not contain lactase, the enzyme needed to digest lactose, or levels of lactobacilli bacteria (like those in yogurt) that are able to produce that effect.
There is also no evidence to support the claim that raw milk can cure or treat allergies and asthma. The study that is often used to support this claim—the PARSIFAL study—focused on milk obtained directly from farms, but some of that milk was boiled. Additionally, pasteurization has little impact on the milk's protein structure, so people with milk allergies are unlikely to tolerate milk, whether it's raw or pasteurized.
As for whether raw is more nutritious, pasteurization does affect the vitamin content of milk, but not appreciably. Vitamin E in milk is naturally low anyway. Although B12 decreases somewhat, one 8-ounce glass of low-fat milk still provides half the recommended daily intake. Vitamin C decreases, but milk is not considered a primary source of C. Milk is, however, an important source of vitamin B2 (riboflavin), providing 45 percent of the recommended daily intake. Pasteurized stacks up evenly with raw here, because vitamin B2 is not affected by heat treatment, but rather by exposure to light.
So what's the verdict? Drink raw milk at your own risk. Although the perceived health benefits sound tempting, there is little evidence to back up the claims. You can get the same nutritional value by consuming pasteurized milk along with a variety of whole foods, but with a substantially reduced risk of a potentially serious infection.
Provided by Tufts University