I've seen several bumper stickers recently espousing the virtues of drinking raw milk. Although selling unpasteurized milk is illegal in most states, you'll find a virtual counterculture that has rejected pasteurization if you search around the Internet. Depending on the website, there are claims that raw milk alleviates allergies, remedies digestive problems, and reduces susceptibility to asthma.
Many of these sources attempt to justify such views with evidence and logic that few clinicians, microbiologists, or public health practitioners would find compelling. In some ways, such views are akin to those voiced from the anti-vaccine movement: They tend to latch on to the occasional, single study with limited findings as scientific validation of their beliefs, while discounting a substantial scientific literature identifying the risks. The truth is that the practice of drinking unpasteurized milk threatens the health of anyone consuming it, especially children and pregnant women.
It's critically important to understand these views (to the extent possible) and not simply write off the people believing them as belonging to a lunatic fringe and call them dumb and stupid. There are raw-milk advocates who eventually come to realize the risks they are taking and change; isn't it better to understand that process and avoid alienating people who might ultimately do the same?
I am reminded of a BMJ Quality & Safety article about Ignaz Semmelweis and the birth of infection control. At the end there is a passage that discusses the inadvisability of trying to convince people of anything by using insults, public humiliation, and haranguing. In talking to (and about) those who advocate drinking raw milk, we should watch the rhetoric. There's a difference between communicating risk and alienating people. Good risk communication can be effective, whereas alienation probably reinforces the behavior in need of modification.
(image source: David Hartley)