Raw (unpasteurized) milk can contain harmful bacteria like Salmonella, E. coli, Listeria, Campylobacter, and Brucella, which may cause serious foodborne illnesses, while pasteurized milk is much safer because heat treatment kills these pathogens with little change in basic nutrition such as protein, calcium, and vitamins. Although some people believe raw milk is easier to digest or more “natural,” scientific evidence does not show clear health advantages, and the infection risk is significantly higher. Raw milk should be strictly avoided by pregnant women, children, older adults, and people with weak immune systems, and the only effective way to reduce risk is proper pasteurization rather than relying on storage or hygiene alone.