Our current HHS secretary has been pushing the narrative that raw unpasteurized milk is good for your health, and the FDA is wrong to overregulate it they way it does (what he calls “aggressive suppression”). He is objectively wrong, but this has resurfaced the public misinformation fight over raw milk.
I last wrote about the topic six years ago, focusing on the question of risk of bacterial infection from raw vs pasteurized milk. The quick version is, pasteurization (which is simply heating milk to kill bacteria) works, it reduces the risk of infection from milk, it is an effective public health measure, and it does not significantly degrade the nutritional value of milk.
A 2017 study concluded: “Unpasteurized dairy products thus cause 840 (95% CrI 611–1,158) times more illnesses and 45 (95% CrI 34–59) times more hospitalizations than pasteurized products. As consumption of unpasteurized dairy products grows, illnesses will increase steadily; a doubling in the consumption of unpasteurized milk or cheese could increase outbreak-related illnesses by 96%.”
This data has not changed. The CDC reports: “During 2009–2021, a total of 143 enteric disease outbreaks that were confirmed or suspected to be associated with consumption of raw milk were reported to CDC.”
Since this is based on reporting this is likely an underestimate. In 2017 it was estimated that 3.2% of the US population consumes raw milk. This has increased to 4.4% more recently. Proponents cite the overall low numbers of outbreaks, but this of course misses the point – if regulations decrease and raw milk consumption increases, outbreak numbers would increase as well. Also, having greater numbers of pathogens passing through cows to humans increases the probability of a zoonotic spillover event from this source.
It’s a lot of risk with no benefit. Previously I have focused on the risk part of this equation, while noting the lack of nutritional benefits. But proponents also claim another benefit claim that I have not previously discussed, that it reduces lactose intolerance. Two putative mechanisms are cited, that raw milk contains bacteria that produce enzymes that help digest lactose, or that the raw milk is itself easier to digest. Neither of these claims, however, is true.
There is no evidence that drinking raw milk is less likely to cause symptoms of lactose intolerance than drinking pasteurized milk. There appears to be only one actual study of the question, which found no difference. Raw milk also contains the same amount of lactose as pasteurized milk.
Raw milk does contain one thing in much larger amounts that pasteurize milk – bacteria. Some of those bacteria are lactobacilli, which can produce beta-galactosidase which does digest lactose. But they do so in insignificant amounts which have no effect on milk digestion. Raw milk, therefore, is not a probiotic.
Even the evidence for the effects of probiotics on symptoms of lactose intolerance is fairly weak, but on the whole there is likely an effect. However, this effect is strongly dose dependent, and you need a high colony count to see it. Again this supports the conclusion that the extremely low counts (of lactobacilli – most bacteria in raw milk are not probiotic but are environmental or pathogenic) in raw milk are unlikely to have any effect on lactose intolerance.
Another claim of benefit touted by raw milk proponents is that it reduces the risk of asthma, allergies in general, or milk allergies specifically. None of these claims are established either. There is no significant protein difference between raw and pasteurized milk and no observed difference in the likelihood of having an allergic reaction.
There is a 2007 study showing an association with the consumption of farm milk and reduced asthma and allergy risk. However, this was not a study of raw milk, it was a study of farm milk, which is often boiled (a form of pasteurization). There is already an established link between living on a farm and lower risk of asthma and allergies, which does likely result from exposure to allergens at a young age. However this has never been established for raw milk.
In the end we have ample evidence for significant risk of harm from consuming raw milk or dairy products, and no significant evidence for any benefit. The FDA is therefore correct to regulate raw milk products in order to reduce the risk of food-borne infections and zoonotic spillover.
