If you’re truly interested in consuming the original Primal brain food, look no further than bone marrow: perhaps the first reliable source of large, fatty animal products our scrappy ancestors were able to procure. Yes, before we became spear-using cunning tacticians surrounding, stalking, and out-maneuvering large prehistoric ungulates, we feasted on the bones of fallen prey. Or, more accurately, we feasted on what lurked inside the bones (and the skulls, for that matter). Animal fat  and protein improved the quality of our diet by making digestion less energy intensive. Bone marrow, especially, was highly caloric and nutrient dense, allowing early human ancestors to divert metabolic resources away from the costly digestion of roughage and toward bigger, costlier brains. This spurred the increase in hominid brain size that we still enjoy today.
That was around two million years ago, when Homo habilis used rudimentary stone tools to strip and smash bones. He was small and relatively diminutive – too small to take down big game – but he could hoist a big smashing stone overhead once the apex predators had gone. And he could probably fend off the hyenas, the vultures, and any other scavengers dead set on sucking the marrow. In fact, we may have learned about the delicious, nourishing paste by watching vultures drop femurs from the sky  and pick out the marrow.
There’s clearly something special (nutritionally) about bone marrow. Animals go for the marrow, instinctively, for example. Wolves given access to full deer carcasses gravitated toward those bones with “high marrow yields,”  taking care to “destroy the epiphyses” where the marrow was most plentiful. When I toss my dog a big smorgasbord of raw bones, organs, and muscle meat, he heads straight for the marrow before anything else, every single time. It goes marrow, liver, heart, muscle meat. It’s interesting to see what the high-powered, raw senses of a nearly obligate carnivore chooses when determining which animal product is best to eat.
As for the nutritional content, consider this data  (PDF) on standard “African ruminant marrow”, courtesy of Loren Cordain. Three and a half ounces of the stuff contain 488 calories, 51 grams of fat  (mostly monounsaturated, as I understand), and 7 grams of protein  – extremely dense. I can understand why we were driven to come up with new methods of obtaining it. The way wild animals and traditional cultures prized it as much or more so than other fatty, rich cuts suggests that there’s more to marrow than just the fat.
As we all know, meat, especially fatty meat, contains more than just a lopsided macronutrient ratio. Meat, or any animal product, really, is the best, densest source of fat-soluble vitamins around. Liver, heart, brains, ribeye are all prize cuts for their taste, their nutrition, and the various bioavailable micronutrients that come loaded in every delicious bite. Plus, marrow isn’t just static stuff inside the bones. It fulfills a role. It fulfills many roles, actually. It’s made of osteoblasts (which form bone cells using minerals), adipocytes (fat cells), fibroblasts (which form connective tissue), and osteoclasts (which are responsible for bone resorption). I was unable to obtain detailed info regarding the mineral/vitamin content of bone marrow, but if it’s involved in bone and connective tissue formation/resorption, there are probably some choice components that make consumption particularly advantageous.
There’s another reason – a big reason, actually – why animals of all stripes are drawn toward bone marrow and why you should head down to the butcher for some bones: the taste. A subtle, creamy nuttiness, sometimes a bit sweet, always extremely rich, is not to be casually disregarded. The taste is incredible, either eaten straight up with a touch of sea salt or as part of a rich, hearty stew. Its high quality fuel imbued with vitamins and minerals, but it’s delicious fuel that’d be worth eating even if it were devoid of nutrition. Luckily for us, though (and counter to what we’re taught about nutrition), what appeals to our taste buds on a basic level usually also nourishes. Marrow may be a “sinful treat” for most, but it deserves to be a kitchen staple for Primal eaters.
Bones are cheap, and most people that buy them buy them for their dogs. You’ll even see marrow bones marked as “dog bones” in shops. Personally, I’m glad they’re an underappreciated food. If people think of them as dog food, they stay inexpensive. Dogs crave them, love them, but they can’t really spur demand and constrain supply. They alone can’t drive the prices up. So, for the time being, marrow bones, even the grass-fed stuff, remain highly affordable.
Look for broad bones with big thick tubes of marrow. The bones themselves are great fun for making stock afterwards, but you’re paying for the marrow, so make sure you pick some meaty ones. I’d skip Whole Foods. They charge about four bucks a pound for marrow bones, and they’re from conventional, grain-fed cows. If you’re buying grain-fed, you might as well buy them from a local grocer for a couple bucks or, better yet, from an Asian grocer for less than a dollar per pound. Grass-fed is best, of course, and the best way to get quality grass-fed bone marrow bones is from local or online farmers. Try Eat Wild  if your farmers’ market meat guy doesn’t carry any. A few of the bone-in cuts will also have a nice shot of marrow, so keep that in mind.
The simplest, best way to prepare marrow is to roast the bones upright at 350 degrees Fahrenheit for 15 minutes. Fat will leak out the bottom, and you want to eat it all, so use a pan, or at least catch the drippings with molded foil. When the marrow begins to slightly bubble, it’s ready to be eaten. Thicker bones may need a bit more time in the oven, or you could do what I do and eat it slightly pink. Buy from a trustworthy, reputable source and you’ll be fine. Use a narrow spoon or fork to scrape out the marrow (you can even use a dedicated marrow spoon , if you can find one) and top with a bit of coarse sea salt. Serve with a small parsley, shallot, and lemon juice salad to cut through the creaminess of the marrow.
Getting every last bit of marrow out can be hard for beginners. The interior of the bone isn’t smooth, but rather rutted and uneven. If your spoon or fork isn’t fulfilling its duty to your satisfaction, use a combination of applied suction and probing tongue. The suction will loosen any stubborn bits, allowing the tongue to snap ‘em right up. Another option entirely is to forgo the cutlery and apply suction directly to the loaded bone. It’s a tricky move, because you’ve got to strike a balance between warm enough to slide out and hot enough to burn your mouth, but if you’re able to master the preemptive slurp, nothing compares to a mouthful of gelatinous marrow.
If you haven’t tried it yet, get out there and buy some marrow bones. Beef is standard, but any other large mammals will work. And the next time you do a big bone-in roast, whether it’s beef, veal, random African ruminant, or lamb leg, treasure the bone. Don’t dump it into the stock pot right away. Instead, lay it out lovingly on a flat, sturdy surface. Slice it lengthwise if you’ve got the means; otherwise, take a sledgehammer or a big rock and reduce the bone to pieces. Pick the shards clean and suck them dry. Then, and only then, may you toss them in the stockpot (although seeing as how those shards went spelunking in your mouth, you may want to limit the resultant soup’s ultimate audience).
Sucking on marrow bones seems to unlock latent primal (small “p”) urges in all of us, but that’s okay (as long as you avoid it as a first date meal). If you find yourself turning progressively more feral as the marrow disappears from the bone, don’t worry. Even vegetarians have been observed scrounging, slurping, and gnawing at the remains of a bone marrow meal. When it comes to getting the last delicious bits of bone marrow, total paleo reenactment is the only justifiable course of action.
Are you a fan of bone marrow? Never tried it? Share your thoughts in the comment board. Thanks, everyone!