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The Definitive Guide to Dairy

I knew going in this was going to be a tricky one, because dairy, especially raw and/or fermented full-fat dairy, resides in a Primal gray area. The literature, the evolutionary reasoning, and the anecdotal reports all unanimously point to sugar [7], cereal grains [8] and legumes [9], processed foods [10], and industrial vegetable oils [11] as being net negatives on the human metabolic spectrum, but dairy is somewhat different. The other Neolithic foodstuffs we can rule out because the science condemning them is fairly concrete and they weren’t on the menu 20,000 years ago. Heck, they weren’t just off the menu; they were basically unrecognizable as food in the raw state. Dairy, on the other hand, is a relatively recent food chronologically, but it is most assuredly and obviously a viable nutritive source in its raw form. It’s full of highly bioavailable saturated fat [12], protein [13], and carbs [14] – in equal portions. You could conceivably survive on milk alone (I wouldn’t recommend it, but you could technically do it; try doing the same with honey or raw millet). Milk is baby fuel. It’s literally meant to spur growth and enable a growing body. Our bodies definitely recognize dairy as food, even foreign bovine dairy. But is it good nutrition?

I don’t know. I’m not sure anyone really does, in fact, which is why I place dairy firmly in Primal limbo. And so, this Definitive Guide to Dairy may come across as being a bit less than definitive, but that’s only because I’m being honest: we simply don’t know whether dairy is suitable for regular human consumption. Whether you include or exclude it from your diet, the decision must be borne from a review of the available literature (Cordain v. Weston Price, for example) with an assessment of the potential risks and benefits, followed by a personal assessment of dairy’s effect on your body (try it, then strictly eliminate it, and note the differences). If you’ve been eating dairy your entire life, your body doesn’t know anything else. In that case, you’ll want to fully drop it for at least a month to get an accurate assessment. Remember – pre-Primal, you probably “felt fine” eating grains and sugar every day. You may have to take the same approach if you really want to figure out what dairy does to you.

You could listen to Dr. Loren Cordain and other strict paleos who adamantly oppose all forms of it. They offer a number of reasons why dairy doesn’t belong in the human diet – mainly lactose intolerance and casein intolerance. Yet, the truth is,  lactose (a form of sugar) and casein (a form of protein) are both found in human breast milk, so each of us – and certainly every one of our ancestors – was not only able to tolerate but to thrive for some time during infancy depending on both of these “questionable” molecules. That’s the main thing that makes eliminating dairy a little less clear cut than eliminating grains and legumes. But let’s look a little closer at the intolerance issue.

Lactose Intolerance

The widespread presence of lactose intolerants, who still make up a majority of the world’s inhabitants, is somewhat compelling evidence that maybe dairy isn’t the ideal food many assume it to be. Worldwide, we see that most people aren’t adapted to lactose consumption after age four, when many of us lose the ability to properly digest lactose (actually gene expression [15] for the enzymes involved in lactose digestion are down-regulated). Nevertheless, it would appear that among many people, most of whom can trace ancestry back to herding cultures, some adaptation has taken place that allows them to continue to effectively digest lactose throughout their lives. I would never argue that a lactose intolerant person should drink milk; if it makes you feel like crap, don’t eat it! At the same time, though, if that same person were to complain about getting enough fat in his or her diet, and olive oil and coconut oil weren’t cutting it, I would suggest incorporating some cream, butter, or ghee. Little to (in the case of ghee) no lactose to speak of, and you’d be hard pressed to come up with a better all-purpose cooking fat. Lactose intolerance won’t kill you if you ignore it. It’s actually pretty impossible to ignore rumbling guts, explosive diarrhea, cramps, and bloating, so I doubt the truly lactose intolerant will miss it.

Casein Intolerance

Casein is the primary protein in dairy. It shares structural similarities with gluten [16], a highly problematic grain protein that can shred the intestinal lining [17] and lead to severe auto-immune issues. Bad, bad stuff, and a big reason why grains are so unhealthy [18]. (And if you’re still not convinced that grains are unhealthy read this [19] (PDF).) Now, paleo opponents of dairy say casein wreaks similar havoc on our guts, and it’s true that gluten intolerance goes hand-in-hand with casein intolerance. But is casein a primary cause of leaky gut, or does it slip in only after gluten has opened the floodgates? Once a floodgate is opened, any protein can enter and cause issues. And after all, casein is the primary protein in human breast milk…


Cordain thinks milk leads to cancer, citing a fairly impressive array of studies that seem to suggest a link between milk consumption and various types of the disease. He fingers betacellulin, one of milk’s epidermal growth factors, as the causal agent. In the fetus and suckling newborn, betacellulin helps with growth and tissue differentiation. It’s completely essential for growing infants. In adults, Cordain says it passes cleanly into the gut, completely intact and free to enter circulation, where it can bind to receptors and enhance cancer cell growth. What Cordain doesn’t mention is conjugated linoleic acid (CLA), which is also found in milk fat (especially raw, grass-fed milk, which is never included in any study) and has been shown to possess anti-cancer effects by inhibiting breast cancer cell growth [20] and reducing the activation of insulin-like growth factor receptors (the same receptors Cordain identifies as sensitive to betacellulin). The studies Cordain cites as support of the milk-cancer connection are interesting, but their messages are muddled. As Chris Masterjohn points out [21], milk proteins mostly appear harmful only when separated from their natural fat. Low fat and skim milk appear to have associations with certain cancers (like prostate), while whole milk appears protective (of colorectal cancer) or neutral. It would be nice to see researchers take a good, long look at full-fat, pastured dairy’s effects on cancer rates. Conventional milk consumption probably isn’t advisable, but the jury’s still out on whether raw, pastured, whole milk is also problematic. We need more data.

Insulin Response

Milk is highly insulinogenic, more than most carbohydrate sources. We’re all aware of the dangers of chronically elevated insulin levels, but that’s also what makes milk such a popular post-workout recovery drink. If you’re insulin sensitive following a tough strength training session, milk’s insulin response can be an effective way to shuttle in protein and glycogen. I don’t do it myself, because I like to fast post-workout [22] (and I don’t like the taste of regular milk) but some people swear by it. This is just speculation, but perhaps the potentially negative effects of milk are negated by the post-workout internal environment (starved muscles, depleted glycogen, insulin-sensitive tissue). Or perhaps those powerlifters are slowly but surely eroding their gut lining. To be on the safe side, maybe limit your milk drinking to immediately post-workout if you’re going to drink it at all.

There isn’t a whole lot of consensus on the subject. People with whom I normally agree on everything regarding nutrition have completely different takes on dairy. Some MDA forum goers report no ill effects, while others complain of joint pain and clogged sinuses from consuming even a single ounce of dairy. More than any other food, dairy seems to be entirely subjective. There is no “one size fits all” approach to it. To be on the safe side and to go “full Primal,” you would technically eliminate it completely, but that may be unnecessary for a relatively large number of people.

In a strange way, this entire blog is just a detailed, science-based map of my own personal journey augmented with anecdotes and experiments from others on similar, but slightly divergent, paths. Much of what I write is founded in science but based on my experiences, and this particular post is no different. When things are gray and murky and the science is unclear and far from definitive, I generally go with anecdote and personal, n=1 experimentation. Personally (and, in a way, this entire blog is just a detailed map of my own personal journey), regular dairy doesn’t generally agree with me. I don’t buy or drink milk. Having said that, I’m a big fan of heavy cream in my coffee and butter in my eggs (and on my steaks and vegetables). I like a nice thick yogurt sauce on lamb, and occasionally either Greek yogurt or fresh whipped cream with berries for dessert. I even have a bit of artisan cheese [23] once in a while. It works for me. I don’t get cramps or gas, and I don’t get leaky gut symptoms from casein alone (gluten is another thing altogether). I’d say, on average, I consume at least one dairy item each day (usually butter), but that’s not a hard and fast rule.

As I mentioned in my book, I think there’s a continuum, a cascading scale of suitability when it comes to dairy. It’s not all created equal.

Raw, fermented, full-fat dairy is probably best.

Tons of traditional, fairly disease-free groups lived with dairy (just as tons of traditional, fairly disease-free groups lived without it), and they all included some form of fermented or cultured product. Cultured butter, yogurt, kefir, clotted milk, cheese – these are traditional ways of increasing shelf life, improving digestibility, and incorporating beneficial probiotics into the gut. Fermentation [24] takes care of most of the lactose, and some posit [25] that it may even positively alter the structure, function, and safety of casein.

Raw, high-fat dairy is next.

Raw butter and cream are minimally processed sources of good saturated fat. They’re free of most lactose and casein, and let’s face it: butter and cream just make everything taste better. If it’s essentially just pure, raw animal fat from grass-fed animals, without offensive levels of milk proteins and sugars, what’s not to enjoy? Ghee is another good choice, and though it technically isn’t raw, it is pure animal fat without a trace of lactose or casein.

Then raw milk.

I don’t advise regular consumption of raw milk, mind you, but if you can tolerate it (no stomach upset, no bloating, no gas, no intestinal issues) an occasional glass is probably OK as a sensible vice [26]. Some farms will even supplement their raw milk with colostrum (the extra rich, “first run” milk that provides even more vitamins and nutrients), resulting in a lower-carb, higher-fat, higher-protein product. Look for that stuff if you’re thinking of buying raw milk.

Organic, hormone and antibiotic-free dairy (full fat, of course).

Bottom line: don’t consume non-organic dairy if you can help it. Avoid homogenized milk if you can, and try not to purchase pasteurized milk (organic or not) on a regular basis. If you’re out getting coffee or something, the regular half and half or heavy cream are fine, and Kerrygold makes a great pastured, pasteurized butter that’s available nationwide.

Other things to consider:

A2 Milk versus A1 Milk

Milk proteins are made up of different beta-caseins, which vary between cow breeds. There are two main categories of beta-casein: A1 and A2, each with different effects. A1 cows (Holsteins and Friesians) produce A1 beta-caseins, which release an opioid-like chemical upon digestion. This chemical, called beta-casomorphin-7 (BCM7), is a protein fragment that figures into the joint pains, digestive issues, and leaky gut symptoms that detractors typically blame on just casein. A2 cows (Jerseys and Gurnseys), on the other hand, produce A2 beta-casein, which has been vindicated. Raw, pastured milk tends to come from Jersey and Gurnsey cows; Holsteins and Friesians produce far more milk and so are used by conventional, factory dairy farmers. The Masai, for example, have A2 cattle.


Goat dairy is another option, with more fat (that’s never homogenized, even when pasteurized), less casein, less lactose, and fewer digestive issues. Structurally and nutritionally, goat milk is one of the closer corollaries to human breast milk, making it arguably more suitable for human consumption than cow’s milk.

In the end, is there a definitive stamp of Primal approval, or Primal disapproval? I just can’t go either way. Sometimes, the correct path is to admit that you simply don’t know. You can read all the blogs you want, pour over every comment, follow every link, and pontificate about every hunter-gatherer group on the planet, but if you don’t try things out for yourself – either by trying certain dairy products or by eliminating them and noting the effects – it’s all just speculation and hearsay. In the murky, milky world of dairy, it’s up to you to decide your ideal path.

Tell me about your experiences. Is dairy part of your Primal eating strategy? If so, what (butter, milk, yogurt, cheese, etc.) and how much?

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