Mar 10 2016

A Raw Milk Fiasco

raw-milkLegislators in West Virginia passed a law legalizing the drinking of raw milk (but not the sale or distribution). Some of them drank raw milk to celebrate, and later came down sick with stomach symptoms.

This is one of those perfectly ironic stories that the internet loves. However, the lawmakers in question are denying that the milk is to blame. Instead they blame a stomach virus that has been going around their capital. A definitive answer is not yet available.

While the story is funny, it is irrelevant to the real question – is raw milk safe, and are there any health benefits beyond pasteurized milk? The answer to both questions is no.

Risks of Raw Milk

Safety, of course, is relative, but there is no question that drinking raw milk entails greater health risk than drinking pasteurized milk. Milk is an excellent culture medium, meaning that there are pathogenic bacteria, parasites and viruses that can grow well in raw milk. The CDC lists the most common:

bacteria (e.g., Brucella,Campylobacter, Listeria, Mycobacterium bovis (a cause of tuberculosis),Salmonella, Shiga toxin-producing Escherichia coli [e.g., E. coli O157], Shigella, Yersinia), parasites (e.g., Giardia), and viruses (e.g., norovirus).

Pasteurization was developed as a method of killing off any infectious contaminants in milk, and the process works.

Raw milk enthusiasts will often cite anecdotal evidence of people who drank raw milk without illness. This is misleading, as anecdotes often are. Drinking raw milk is not a guarantee of getting sick, it’s just a risk. The probability of getting an infection from raw milk is much higher than pasteurized milk. There are also frequent outbreaks of foodborne illness linked to raw milk, including serious illness and death.

Proponents argue that good farmer practice can reduce this risk, and it can, but not to zero. Keeping cows healthy and clean, keeping equipment sterile, and good practices during milking and storage are all important and they do help. However, even the best practices with a completely healthy cow does not eliminate the risk of contamination.

By far the most effective method of eliminating infectious contaminants is pasteurization.

Raw Milk is Not Healthier

Raw milk advocates are committing the appeal to nature fallacy, with a knee-jerk emotional reaction against “processed” foods. As with any anti-science or unscientific ideological group, they distort and cherry pick the scientific evidence to make their case.

One claim is that heating milk degrades vitamins. This claim can be filed under true but misleading. A systematic review of studies addressing this claim found that some vitamin levels were mildly decreased in pasteurized milk, however, milk is not a significant source of these vitamins in the first place, so the effect on nutrition is negligible.

Another claim is that heating degrades certain milk enzymes. This is also true but irrelevant. We don’t need milk enzymes anyway. We make our own digestive enzymes. Milk enzymes are just another source of protein and it doesn’t matter if they are degraded and not functioning as enzymes – that would happen once they hit our stomach acid anyway.

Moving on from misleading to just making stuff up, some raw milk advocates claim that raw milk prevent asthma, allergies, and even cancer. There is no compelling evidence for any of these claims. Existing studies are small and of poor methodological rigor. There is preliminary evidence for reduced asthma in children growing up on farms, but it is not possible to isolate drinking raw milk as the important factor in this. There are many other factors involved in living on a farm.

Yet another claim is that pasteurization oxidizes the milk fat, which makes it unhealthy. Oxidation can occur in milk, but it has a variety of causes, which include:

  1. Equipment surfaces improperly cleaned.
  2. Minerals in the water supply.
  3. Acid water and copper tubing.
  4. Use of chlorine sanitizers.
  5. Stored forages low in vitamin E.
  6. Feeding high levels of vegetable fats, i.e. soybeans, cottonseeds.

Oxidation can degrade the flavor of dairy products, especially high fat products like butter and ice cream. For this reason there are many steps that can be taken to reduce oxidation, including homogenization of the milk.

Pasteurization actually has a small and complex effect on oxidation. Heating can actually increase antioxidant activity and degrade the oxidizing effect of copper, depending on temperature. At certain temperatures pasteurization can slightly increase oxidation. Overall the effect is insignificant. Further, oxidation is something that is carefully managed in milk production because of the effect on taste.

Finally, raw milk advocates extol the virtues of beneficial bacteria in milk – the probiotic argument. Probiotics are a separate complex topic, but the quick bottom line is that the bacteria in your gut form a complex ecosystem. Getting extra bacteria in your food does not alter that ecosystem. You don’t need, nor do you benefit from bacteria in milk. If, despite the lack of evidence, you want to eat probiotics, then you can buy products that have had specific beneficial bacteria added. You don’t need to take the chance of whatever bacteria happen to be in your raw milk.


Advocating for the consumption of raw milk is an ideological unscientific position. Consuming raw milk entails greater risk without any proven health benefit. You can get all the nutritional benefits from milk by consuming pasteurized milk products.

Arguments put forward for raw milk all involve a significant distortion of the scientific evidence, much like the anti-vaccine movement or any science-denial movement.


29 responses so far

29 thoughts on “A Raw Milk Fiasco”

  1. Michael Finfer, MD says:

    Why did the raw milk have nothing to do with the illnesses? Because correlation does not equal causation!

    Years ago, in a different environment, we had 14 cases of Salmonella associated with a sandwich platter supplied by a drug rep. The owner of the restaurant viewed this as an affront because he did not think that 14 cases was enough to pin it on him.

    And, yes, the drug rep was one of the 14 cases.

  2. carassius says:

    I’m a federal veterinarian. Many diseases potentially spread via raw milk, one of which is bovine tuberculosis (Mycobacterium bovis as referenced above). The USDA, state animal health agencies, and dairy managers (of all size dairies, many of which are organic nowadays) do everything they can to eradicate these diseases. You don’t really hear much about people getting ill with cattle TB nowadays, at least in the USA, but it is still here and veterinarians are still dealing with it frequently.

    Cattle traced out of this dairy are all over the USA now and the USDA is busy tracing and testing herds large and small. Thank goodness there haven’t been any confirmed cases of human disease (not sure about exposure) from this that i’m aware of. If you’re drinking raw milk or raw milk products I sincerely hope you have good health insurance and aren’t forcing it on the young, old, pregnant, or immunocompromised.

  3. Kawarthajon says:

    Good article! What gets me with a lot of these issues, is the misconception that people are getting unhealthier because of all the “toxins” and that we need “natural” products like these to be healthy. Meanwhile, life expectancy is continuing to rise (at least in wealthy countries), even in the face of obesity and other negative health trends. People do not put enough focus on the important factors in your health – sleep, exercise, vaccines and hygiene. Obviously, eating healthy foods is a keystone to being healthy, but drinking raw milk is not the answer. I wonder if some of these trends, like anti-vaccine campaigns and raw milk advocates, as well as people turning to naturopath “doctors” instead of real doctors, will actually begin to have a negative impact on life expectancy?

    As an aside, here’s a sad story:

  4. carassius says:

    Oh…one more thing. Of the bacterial agents listed in the article I would add Coxiella burnetii, or Q Fever. I believe this bacteria is the agent upon which the current pasteurization standard of 161 deg F for 15 sec is based.

    A couple of the other bacteria listed are coliform and/or are generally based on sanitation (poop on the outside of the teat) BUT one of the cows can potentially have an infected quarter (one of the four teats) which is “spitting” out bacterially contaminated milk to include Staph and Strep and others. Even the most holistic, granola, cow-loving raw milk distributor could easily miss this for a time and sell contaminated milk.

    If you drink raw milk in any other developing country especially including the middle east you should consider yourself absolutely insane (IMHO).

  5. RC says:

    About the only raw milk positive I can see is that its significantly easier to make cheese from raw milk than it is from typically processed milks – ultrapasteurized milk doesn’t set right, and homogenized milk does some weird things -although supposedly its beneficial if you’re trying to make traditionally goat/sheep cheeses with cows milk.

    Anyways – that’s such a small concern.

  6. petrossa says:

    in france raw milk products are staple diet . Strangely enough the number of raw milk induced diseases isn’t higher than elsewhere. One would expect to see a real cluster of related infections, but no. Same for raw eggs.
    In most restaurants you can order a tartare maison, which means raw minced beef meat topped up with a raw egg.

    Having eaten many such products, as many compatriots one can only conclude that USA extreme hygiene only leads to less resistant population.

    Which probably is supported by the huge number of Americans going abroad suffering from intestinal troubles.

  7. mumadadd says:

    “extreme hygiene only leads to less resistant population.”

    This is possibly the reasoning behind the claim that raw milk prevents asthma — hygiene hypothesis.

  8. MikeB says:

    “Drinking raw milk is not a guarantee of getting sick, it’s just a risk.”

    Very wise line.

    I’m in 99% agreement with this. We have a cow here, and I rarely drink the milk (it’s udderly fattening), but when I do drink it I absolutely love it, totally aware of the increased risk, under no illusions that it’s “better” health-wise. It’s. Just. Yummy. A glass of super-cold fresh milk, separated into cream layers–there’s nothing like it.

    There is no way to home-pasteurize milk without it tasting scorched, which is a pity.

    We use our raw milk to make hard cheeses (aged at least 60 days) and when we make yogurt and cottage cheese we absolutely pasteurize it to control the culturing: the scorched taste doesn’t bother in these cases, for some reason.

    The Raw Milk Religion makes us home farmers look bad. I am absolutely against people giving raw milk to their children, and all raw milk products need to be prominently labeled for risks.

    In the twelve years we’ve had a cow, we’ve never gotten sick. But I don’t tempt fate that much either.

  9. MikeB says:

    I should add: it’s the cream portion of milk that gets “scorchy” when you heat it to 185 degrees. Yogurt is skimmed to begin with so the scorchiness is reduced.

  10. petrossa says:

    asthma in any case is not related to air pollution so some other mechanism must be at play

  11. My parents are apparently part of an illegal milk ring. They live in suburbs, every Saturday they drive downtown, park near (but not too near) to an uninhabited semi truck. They leave a wad of cash in a cash box up front, then go to rear to get an unmarked paper grocery bag filled with their unpasteurized milk order. The bottles inside are quite prominently labeled as “not for human consumption”. They then sneak off, whistling casually, and then high tail it out of there. It’s real cloak-and-dagger shit.

  12. RC says:

    MikeB – you only need to go to about 165 to pasteurize milk (for 15 seconds) (or 145 for 30 minutes, which seems like a drag)

  13. MikeB says:

    RC, thanks. It’s a thoughtless typo. I have noticed, though, that yogurt pasteurized at a higher temp. tends to set better, but that just might be the cow, too. I’m amazed at the different properties of milk from different breeds of cow. And, yes, heating is a drag on a stove top.

  14. zorrobandito says:

    We both just contracted food poisoning early this week, source unknown. Quite probably from perfectly normal eggs( but unpasteurized), which we soft-boiled as usual.

    This was such a totally miserable experience that I would do virtually ANYTHING to avoid having it happen again. You have no idea. The intestinal pain is beyond belief. Short, OK, but not short enough. It’s two days later and I still cannot even think of eating.

    People, you don’t want to take chances with this thing. I know raw milk is yummy, I’ve had it myself right from the cow, but it’s not that yummy.

  15. banyan says:

    I make yogurt with normal, store-bought, pasteurized milk. When I look for tips on making my yogurt better, a lot of people recommend starting with raw milk. This doesn’t make sense to me, because the first thing you do when making yogurt is heat it to 180 degrees, which should pasteurize it. That way you control exactly what bacteria will be in there.

    Is there any reason that starting with raw milk would result in better yogurt?

  16. Willy says:

    Coincidentally, I tasted my first raw milk last week. I’ve been looking for it casually for some time so as to use it to make an aged cheddar. My understanding is that long aging eliminates the risk and some cheese sites recommend raw milk for aged cheeses like Cheddar, Gouda, etc. Anyway, I may not have the taste buds some folks do, but I didn’t see a big difference in the taste of the milk itself, certainly not enough to make it worth the risk. I don’t plan on drinking raw milk due to its risks, but it was fun to try it. I also used to to make some yogurt, but that process involves heating milk to 180F, so it ends up pasteurized. The yogurt was fine but not much different, if at all, from yogurt made with store-bought, pasteurized milk.

    banyan: I’m guessing that maybe “double” pasteurizing might alter more milk proteins than single pasteurizing, but I couldn’t really tell any difference. All cheese makers say ultra-pasteurized is bad for cheese making. Have you tried yogurt with ultra-pasteurized? I do know that low/no fat milks make a less “solid” yogurt, though my home made is always runnier than store-bought because I don’t add powdered milk or stuff like xanthan gum.

  17. MikeB says:

    The reason I start out with raw milk to make yogurt is–well, I have a cow, which gives raw milk, which has to be heated (pasteurized) before it is cultured.

    But, yes, I’ve used store-bought milk, too, which makes fine yogurt.

  18. MikeB says:

    Oh–and using raw milk allows a cultured creamy layer of creamy cream to rise to the top of your yogurt. Store-bought milk being homogenized does not give that delectable effect.

  19. etatro says:

    Ever since I was about 24 and developed a taste for soy and almond milk, I’ve found cow milk to be gross. I can’t quite describe it, but the texture in my mouth, and going down my throat makes me gag, and the smell in my nose after drinking it reminds me of all the unpleasant whiffs of mostly empty milk cartons during my childhood. When I see people drink it, it grosses me out, “you’re drinking the mammary secretions of a hoofed animal that stands around in feces with all day, then has robotic arms attached to its breasts to pump out these secretions.”

    I just imagine a cow head sticking out of cage, and a thought bubble from the cow remembering greener pastures.

    I’m not at all a vegetarian, greenpeacy, crunchy granola type; but for some reason, the very concept of cow milk just freaks me out.

  20. etatro says:

    On rereading, I should tone that down, the concept of cow milk gives me slight heeby jeebies. I don’t go lose control and go nuts in the dairy aisle.

  21. mumadadd says:


    “I’m not at all a vegetarian, greenpeacy, crunchy granola type; but for some reason, the very concept of cow milk just freaks me out.”

    Me too when I really think about it, which isn’t often.

  22. mumadadd says:

    That wasn’t meant to sound dismissive, by the way. When I think about the fact that the meat I eat is a former sentient being I get a similar feeling, but I just sort of shove it to one side.

  23. BillyJoe7 says:

    “I just imagine a cow head sticking out of cage, and a thought bubble from the cow remembering greener pastures”

    Since when are cows kept in cages???
    In any case, you could always get yourself a goat and milk it yourself! 😀

  24. Willy says:

    I recognize the down sides, but I still love milk and a nice medium rare ribeye., not to mention a nice lamb chop or BBQ’d chicken thigh. To ignore our past is to be wrong. Were it not for humans, cows and other domesticated critters would likely be extinct.

    We just put down one of our two cats (they were sisters). The vet called while the cat was still under anesthesia and told us she wouldn’t likely live but another week or two. It was an easy choice. Why make a cat suffer? Our cat had a GREAT life! I AM NOT defending industrial cattle production, but animals do not fear death. I think people who do not recognize our omnivorous past and who condemn meat-eaters are naive at best.

    I LOVE cow’s milk products (sheep and goats too). Gimme some good old Parmesan, Cheddar, Gouda! I make my own yogurt and a few other cheeses. Thanks to the creatures who provide my milk products and my meat! Alas, we are higher on the food chain than you are.

  25. Lukas Xavier says:


    Having eaten many such products, as many compatriots one can only conclude that USA extreme hygiene only leads to less resistant population.

    I would think that when eating e.g. raw beef, hygiene standards would be higher than normal. Are there really no special requirements in France for meat intended for tartare?

  26. ccbowers says:

    “Is there any reason that starting with raw milk would result in better yogurt?”

    banyan. The main difference would be that raw milk is not homogenized (in addition to not pasteurized) so that the final product will separate. This is assuming that you actual heat to required temperature (above approx 180F/82C) to kill any bacteria and to denature more of the proteins, resulting in a thicker end-product. If you skipped this heating step, you will have a much thinner product and you will have other bacteria competing with your culture, which is not a good thing. Of course people will still do it to obtain a more “natural” product, but of course natural does not equal better.

  27. ccbowers says:

    “in france raw milk products are staple diet . Strangely enough the number of raw milk induced diseases isn’t higher than elsewhere… one can only conclude that USA extreme hygiene only leads to less resistant population.”

    Actually, this isn’t true. I can’t speak to your vague “elsewhere,” but the rate of foodborne illness attributed to unpasteurized dairy is significantly higher in France than the US as a whole. If you can access the 2001 study by De Buyser, et al. you’ll see some comparisons in rates between countries.

    Even in France, pasteurized milk is much more common than raw milk, and raw milk cheeses that are aged do not carry the same risk. So, while people tend to lump raw dairy products together, it is the raw milk itself, and young cheeses made from raw milk that are the highest risk

  28. flies says:

    Health aside, raw milk cheese is qualitatively different from pasteurized. I am 100% willing to expose myself to some risk to eat raclette, which is one of those young raw milk cheeses that you can’t import. It’s super delicious. Gimme gimme.

    I’m a computational biologist, and I’m wondering, idly, whether some sort of meta genomics or other data driven process could be used to obtain the ideal cultures to add to pasteurized milk to make the cheese taste right…

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