What is it about raw milk that rouses such passions? A few minutes spent researching the subject on the Internet soon turns up all manner of individuals and organisations promoting the supposed health, nutritional and taste benefits of drinking milk fresh from the cow, while deriding the pasteurised version as a pale shadow of the real thing. The evidence for any dietary advantage in drinking raw milk appears at best anecdotal and at worst complete nonsense. As far as I can see, the way milk is processed will make virtually no difference to the health of anyone eating a reasonably balanced diet. Nevertheless, raw milk can be purchased and drunk in much of the developed world.
Most supporters of raw milk dismiss the risks of milk-borne infections as too small to worry about, but is this true? This week the European Food Safety Authority (EFSA) addressed the issue by publishing a full assessment of the public health risks associated with raw milk consumption. The EFSA expert panel concluded that untreated milk can carry a range of pathogens, notably Campylobacter, Salmonella and Shiga toxin-producing E. coli. They identified 27 disease outbreaks over a six-year period that were directly attributable to raw milk. Since there are likely to be many more unreported cases, the overall risk looks significant, though hard to quantify. There would be a justifiable demand for urgent action if any processed food product were responsible for that many disease outbreaks.
Until about 1890, all milk was consumed raw. Pasteurisation was introduced initially to help lengthen shelf life as milk was transported over longer distances to supply the populations of fast growing cities. But it soon became clear that the process was helping to reduce milk-borne disease too, especially tuberculosis and brucellosis. In the early part of the 20th century milk pasteurisation brought substantial public health benefits and was a significant factor in limiting the spread of disease. Today, TB and brucellosis are rare in dairy cattle and regular testing helps keep infected milk out of the food chain. Dairy hygiene and temperature control are also immeasurably better than they once were, all of which means that raw milk is far less hazardous than it was a hundred years ago. But as the EFSA experts point out, a risk remains and the only sure way to eliminate it is to heat treat milk.
Personally I am of the opinion that if people want to drink raw milk, they should be allowed to do so. But they also need to be fully aware of the risks. There will always be a possibility that raw milk might contain microbial pathogens – no matter how hygienic the dairy – at least until someone redesigns the dairy cow so that its udders are no longer in close proximity to its anus.