A streamlined stack of supplements designed to meet your most critical needs - Adapt Naturals is now live. Learn more

Dairy: Food of the Gods or Neolithic Agent of Disease?


Last updated on


One of the most contentious issues in the Paleo nutrition community is whether dairy products are health-promoting or disease-causing.

On one end of the spectrum you have Loren Cordain and his group, who claim that dairy is not fit for human consumption for two reasons: 1) because it’s a neolithic food and not part of our evolutionary heritage, and 2) because of proposed physiological mechanisms by which dairy causes harm when consumed. On the other end of the spectrum you’ve got folks like Kurt Harris, Stephan Guyenet, Chris Masterjohn and the Weston A. Price Foundation who have pointed out the many health benefits of dairy and are generally in favor of its consumption.

My answer to the question of whether dairy is healthy are harmful is, in short: it depends. But before we get into the factors I think the answer depends on, I want to briefly address why I don’t take the evidence against dairy very seriously at this point.

Paleo re-enactment isn’t the goal

I agree with Dr. Kurt Harris on this one.

We can look to the Paleo era to determine what was evolutionarily normal for humans, but it doesn’t follow that anything that falls outside of that norm is automatically harmful.

The argument that we shouldn’t eat dairy now because we didn’t eat it 2 million years ago – without supporting clinical evidence – is not convincing.

There’s also the inconvenient (for the anti-dairy set) matter of people like the Masai and Loetschental Swiss that Weston A. Price studied, who were free of modern, degenerative disease despite receiving a large percentage of calories from dairy products.

Human evidence is more convincing than proposed mechanisms

Cordain’s group has published and reviewed several papers proposing various physiological mechanisms by which dairy causes harm. One recent example is a paper by Melnik called Milk Signalling in the Pathogenesis of Type 2 Diabetes. The theory presented is that milk consumption beyond the weaning period may overstimulate pancreatic beta-cells and promote beta-cell apoptosis. Since proliferation and apoptosis of beta-cells are hallmarks of type 2 diabetes (T2DM), it follows that milk consumption must contribute to T2DM.

Or does it?

If that theory were true, we might expect to see increased rates of T2DM in people consuming dairy products. But in fact we see just the opposite.

This study looked at serum levels of trans-palmitoleic acid, a fatty acid found in milk, cheese, yogurt and butter, and correlated them with risk factors for diabetes. Here’s what they found:

At baseline, higher circulating levels of trans-palmitoleic acid were associated with healthier levels of blood cholesterol, inflammatory markers, insulin levels, and insulin sensitivity, after adjustment for other risk factors. During follow-up, individuals with higher circulating levels of trans-palmitoleic acid had a much lower risk of developing diabetes, with about a 60% lower risk among participants in the highest quintile (fifth) of trans-palmitoleic acid levels, compared to individuals in the lowest quintile.

Translation: people with the highest trans-palmitoleate levels had 1/3 the risk of developing diabetes over the three years volunteers were followed. Not only that, after adjusting for confounding factors trans-palmitoleate levels were associated with smaller waist circumfrence, lower triglycerides, higher HDL and lower C-reactive protein.

Since trans-palmitoleic acid is a fatty acid found in the – you guessed it – fat of milk, the study also supports the idea that full-fat, whole dairy products are beneficial. This directly contradicts the low-fat hysteria we’ve been brainwashed with for so many years. But I digress.

Stephan Guyenet blogged about this study and re-wrote the authors’ conclusion in more straightforward terms:

Our findings support eating as much butter as possible****. Don’t waste your money on low-fat cream, either (half-n-half). We’re sorry that public health authorities have spent 30 years telling you to eat low-fat dairy when most studies are actually more consistent with the idea that dairy fat reduces the risk obesity and chronic disease.

Since this was an observational study, it doesn’t prove that dairy fat reduces the risk of T2DM. But it does suggest that the converse isn’t true.

Another study found that people with the highest levels of milk fat biomarkers, suggesting they consumed the most dairy fat, were actually at lower risk of heart attack; for women, the risk was reduced by 26 percent, while for men risk was 9 percent lower.

Another study showed that people who ate the most full-fat dairy had a 69% lower risk of cardiovascular death than those who ate the least.

Finally, this literature review of 10 studies found that milk drinking is associated with a small but significant reduction in heart disease and stroke risk.

I could go on, but I think you get the point. Which is this: evidence of what happens when people actually consume dairy products is a lot more convincing to me than proposed mechanisms of how dairy may effect humans.

The problem with isolating certain effects of a nutrient or food, and then making predictions based on those effects, is that we might miss some other quality about that food that negates the proposed effect.

That’s a mouthful, so let me explain.

T. Colin Campbell is (in)famous for his research linking casein, a protein in dairy products, with cancer. He then made the huge and unsupportable leap to concluding that all animal proteins cause cancer and should be avoided. Most of you know the rest of that story.

However, what Campbell neglected to notice, or mention, is that whey, another protein found in dairy, has anti-cancer effects that completely cancel out the cancer-promoting effects of casein. Oops! This is why it’s so important to study whole foods, not just nutrients.

So let me finish this section by saying that I believe the weight of the evidence on dairy consumption suggests that it is not only not harmful, but quite beneficial.

Like what you’re reading? Get my free newsletter, recipes, eBooks, product recommendations, and more!

When dairy may not be beneficial

However, as in most things, there are exceptions. Many of you reading this are probably sensitive to dairy and don’t tolerate it well. I certainly have patients that this is true for, and it’s not at all uncommon.

What’s the deal? Why does it seem to benefit some, but cause problems for others? In my opinion the answer boils down to the health of the gut. If someone has compromised intestinal permeability, or “leaky gut”, it’s more likely that their immune system will respond to potentially allergenic components in milk such as alpha- and beta-casein, casomorphin and butyrophillin.

This is especially true for people who are gluten intolerant, because it has been shown that milk proteins commonly cross-react with gluten. Put another way, if you react to gluten, it’s more likely that you’ll also react to milk.

Along these same lines, people with small intestine bacterial overgrowth (SIBO) – which is one of the major causes of irritable bowel syndrome (IBS) – may be more likely to react to milk because the bacteria in their small intestine aggressively ferments lactose, the sugar in milk, causing gas, bloating and other G.I. symptoms.

Not all milk is created equal

Something that irritates me is that raw and pasteurized dairy is often discussed as if it’s the same thing. It’s not. Raw dairy is a whole food, and pasteurized dairy is a processed food.

While it’s true that some people (described above) react to the proteins in milk, most who are sensitive are reacting to the sugar in milk: lactose. The enzyme lactase must be present to hydrolyze lactose into its constituent compounds, glucose and galactose. Somewhere between 1% – 95% of people don’t produce lactase on their own, depending on race and ethnicity.

In a sign of nature’s wisdom, raw milk contains lactase, the enzyme needed to digest lactose. Pasteurization, however, kills lactase. So if you don’t produce your own lactase, you’ll have a hard time digesting pasteurized milk. But that doesn’t mean you can’t tolerate raw milk. I can’t tolerate pasteurized dairy myself, but I don’t seem to have any problems with raw dairy.

So the answer to the question I posed in the title of this article isn’t so simple, and it depends on several factors:

  • The status of your gut barrier
  • Whether or not you have SIBO or IBS
  • Whether or not you’re gluten intolerant
  • Whether you’re eating raw or pasteurized dairy

If you’re not sure where you stand with dairy, the best approach is to remove it for 30 days and then reintroduce and see what happens. Elimination/reintroduction is still the gold-standard for determining sensitivity to a particular food.

But if you tolerate it well, I haven’t seen any evidence in the literature that convinces me you shouldn’t be eating liberal amounts of full-fat dairy.

ADAPT Naturals logo

Better supplementation. Fewer supplements.

Close the nutrient gap to feel and perform your best. 

A daily stack of supplements designed to meet your most critical needs.

Chris Kresser in kitchen


Join the conversation

  1. Any references for the claim that raw milk contains lactase? http://www.fda.gov/Food/FoodSafety/Product-SpecificInformation/MilkSafety/ConsumerInformationAboutMilkSafety/ucm247991.htm says that raw milk contains no indigenous lactase and doesn’t have high enough levels of Streptococcus thermophilus or Lactobacillus bulgaricus to cause the levels of lactase secretion that are seen in fermented dairy. On westonaprice.org, all I could find was a document describing a survey of families who purchase raw milk that found that many of them reported fewer problems with raw milk than with pasteurized milk. With that said, I’m all for people experimenting to figure out what works for them — if someone is lactose-intolerant (I’m not), seeing if they do better on raw milk is worth a shot.

    The majority of the pro-raw milk literature that I can find online quickly veers off into arguments about farmers’ rights and pathogens. I haven’t had much luck finding scientific support for claims that vitamins and lactase are destroyed by pasteurization. Stated more succinctly, if I buy milk, why should I get it from Claravale or Organic Pastures instead of from Straus?

  2. You mention that raw milk and pasteurized milk are completely different, but shouldn’t we distinguish between the different methods of pasteurization as well? And in particular the temperature used?

    How do you feel about VAT pasteurized milk as opposed to UHT pasteurized (heating to 145°F vs 275°F)?

    I understand the argument in favor of raw milk for the purposes of drinking it directly. But I’m not sure I understand why raw milk is preferable to VAT pasteurized milk when making butter or cheese or any product that will be used for cooking anyways. Is the benefit only when they’re eaten without further cooking?

    Do you consider milk pasteurized at low temperatures to be more of a “processed” product than raw milk that’s been used for cooking purposes? Is it bad for our health to bake with milk based products (300°F) since we’ll essentially be pasteurizing the milk?

    Wouldn’t cooking have the same effect on enzymes and proteins as low heat pasteurization? What’s the advantage of raw milk products in those cases? Or is there a concern other than the effects of temperature?

    This is what confuses me the most about the raw milk debate :-/ Hoping you can share your thoughts on it.

    • All of Daniel’s questions are my questions as well! If we don’t have access to raw is good quality non-homogenized vat pasteurized milk still good for us? and if not, then how does cooking with milk, butter, cream not alter the product in a way that’s harmful?

  3. Thank you very much, Mr. Kresser, I am looking forward to your article! I am very interested in “how much IGF-1” is really left after fermentation (in absolute numbers) and if this leads to a significant raise in IGF-1 in the human body! This is a topic that really needs to be discussed as so many questions are still open!

  4. I would appreciate if the issue of dairy and IGF-1 would be further discussed. IGF-1 seems to be reduced by fermentation but how are the exact numbers? And is it really proven that it increases cancer risks? Also, a M. D. called Gary Steinman has conducted extensive research on how dairy promotes human twinning via increased IGF-1 levels which then lead to releasing more than one egg during ovulation. I would love to learn about the experts`point of view on this still there are so many conflicitng opinions!

    • I’ve seen a study, which I’ll discuss at some point later, that fermentation reduces IGF-1 fourfold. If you look at most human studies of people consuming dairy, rather than mechanistic studies, the evidence predominantly suggests health benefits.

      • Have you written a follow up article yet on your perspective on this? I have been listening to the food summit which is on right now and am quite annoyed how they are demonizing all dairy and meat. They should have called it the vegetarian summit. I don’t suppose they invited you to speak:)

        • I have exactly the same question! Would be great if Chris could write a follow-up piece on IGF-1! Thanks in advance Chris 😉

  5. Chris. I am a human doc and also a vet. About the raw milk, you must consider the risk of zoonoses carried by raw milk. Many countries, including mine (Brazil) has Brucelosis as a relatively common disease found on cattle. The Brucella bacteria causes mainly miscarriage problems in cattle, but it´s found on milk and can infect humans causing ooforitis and orchitis. Nasty long and multi-antibiotic therapy to kill the buggers, not to mention the reprodutive tract damage.


  6. When I eliminated dairy I also eliminated my cluster migraines. I eat no grains or legumes so my gut is super happy, but if I eat any dairy I get migraines and sinus problems. Is this common?

  7. Thank you for this: “Paleo re-enactment isn’t the goal.”

    When I first read the paleo diet, I kept wondering why we had elevated early humans so much. If transportation and communication can progress, certainly eating can as well.

  8. I’m not a big fan of scientific studies >> “Lies, Damned Lies, and Medical Science.”www.theatlantic.com/magazine/archive/2010/11/lies-damned-lies-and-medical-science/8269/

    Can we milk be both good and bad? I think so. Consider the following logic:

    Mother’s milk of all different mammals contains similar growth hormones. In humans and in cows, these hormones are identical. Both contain seventy amino acids in the identical sequence. This is the only known example in nature in which one identical hormone is shared by two species. In humans, this hormone is called insulin-like growth factor one (IGF-1). These growth hormones enhance growth and development. This is important for infants for obvious reasons. Adults consuming milk and other dairy products also absorb these growth hormones (IGF-1 survives stomach acidity in both babies and adults because it is buffered with casein and fat molecules). These growth hormones encourage normal cell growth in both infants and adults. Besides stimulating growth of normal cells, they also stimulate growth of cells that have been damaged or mutated. Over time, the number of damaged or mutated cells increases. Therefore, the more milk and dairy one consumes, the more mutated and damaged cells are available to catalyze and grow.

    Non-milk dairy products concentrate the load of growth hormones. It takes twelve pounds of milk to make one pound of ice cream and ten pounds of milk to produce one pound of hard cheese. Eating these foods only increases the delivery of growth hormones. By consuming dairy one’s body will grow – both the good (muscles) and the bad (cancerous cells).

  9. I grew up on a dairy farm, that said I grew up drinking raw milk straight from the bulk tank. Never had a problem with drinking milk as a kid and it was good stuff. It wasn’t until I was 16 and we stopped dairy farming and started buying pasterized milk that I noticed a reaction, of course at the time and I didn’t realize that and assumed it was growing pains. Looking back I now realize how lucky I was to be raised on a farm (we raised all of our own food (pig, chicken, duck, rabbit, cow, huge vegetable garden). I wish now that I’m an adult and looking to start a family of my own, that I still had that kind of access to raw milk (I’m sure I can buy it, but it’s not the same). My boyfriend has his own beef cattle that he raises to feed us and the neighbors and I have a garden, so we are gradually working towards raising a family in the lifestyle that we were both raised, but it isn’t easy, nor cheap, but it’s worth it in the end to have good health.

  10. My main concerns with milk are the possible effects on your immune system, primarily from the BCM7 resulting from A1 milk, and on your endocrine system, from the high levels of hormones in commercial milk.

    The effects from these might not be obvious for a long time, but if your pancreas is being damaged even though all your blood markers look good in the meantime, that obviously isn’t a good tradeoff.

    I clearly have milk sensitivities, and feel better when I don’t drink it. Raw butter seems to be OK, as long as I don’t eat too much of it too often.

  11. Thanks very much for this! I’ve been wondering about this for some time now. This article puts things into very clear perspective . Great job!

    Now if only I could find a good source of raw dairy here. Safeway is starting to sell organic raw cheese in their dairy section, but I’ve been told raw milk is illegal to sell retail here.

  12. Fantastic, well writtin, descriptive article. I totally agree, 100% with everything you wrote. Thanks for sharing, and I will pass this on!

  13. Studies demonstrating the beneficial effects of milk (or certain milk components) on raising the body’s glutathione level are too numerous to list here. Whey protein, and more specialized extracts, such as Immunocal, are often touted for their anti-cancer benefits, one of the main reasons apparently being the glutathione boosting power of such components. Health food stores stock a number of different colostrum products, such as that by Symbiotics, which makes “Colostrum Plus,” a delicious powder. Those manufacturers would no doubt take issue with Campbell’s lunacy. Lactoferrin is also a useful component of milk, particularly of colostrum. Numerous adjuvant cancer treatment protocols suggest the use of such substances. I note that the LEF and others are now touting a different extract, bioactive sweet whey extract (BSWE), in the treatment of psoriasis. Holy cow! Pardon me, I hear the milk calling me, it wants me to drink it…. 🙂

  14. Tim: I’m familiar with the A1/A2 issue, but I haven’t looked deeply enough into it to tell you anything you probably haven’t already learned from Woodford’s book.

  15. How do you feel about A1/A2 milk, per the book, The Devil in the Milk by Keith Woodford? A lot of evidence that A1 milk (most of what is in the US) can cause health problems, especially, as you say, when someone has a compromised gut.

  16. In order of reintroduction:

    – Ghee
    – Butter
    – Kefir or yogurt fermented for 24 hours
    – Cream
    – Hard cheese
    – Yogurt (commercial, fermented less than 24 hours)
    – Soft cheese
    – Milk

    All raw when possible. If you have to choose what to use organic pasteurized with, I’d say ghee and yogurt (since you’re heating it and killing the lactase anyways in both cases).

  17. Thank you, Chris.
    Do you recommend fermented milk products, home-made ghee, or raw butter for a reintroduction? I wonder if it’s important to make the ghee out of raw butter or if a grass-fed, organic butter would be fine.

  18. Wish more of these studies about gluten and dairy would have been around when I was growing up. Thank you for writing such a wonderful article with information that can help those that need to be diagnosed and confirmation for those of us that (finally) are.

  19. Nice write. For many people it seems tough for them to lose weight on dairy. but if they tolerate it why not. Or do like the Whole9 peeps do it for 30 days and if you feel better with or without, go that route.

    Thanks for your insight!