Eating raw marine mammals isn’t the same as eating cooked land mammals

Tuesday, August 22nd, 2017

A couple decades ago, when I first became interested in evolutionary fitness and ketogenic diets, I read that the Eskimos had traditionally lived on a diet almost entirely bereft of carbohydrates — a diet that Vilhjalmur Stefansson tried to promote amongst non-Eskimos in magazine articles and then in his 1946 book, Not by Bread Alone.

Traditional Inuit Diet

But Stefansson Westernized the Inuit diet of raw marine mammals and instead promoted a cooked, all-animal-food-diet, including dairy and eggs — a difference that matters once you realize how marine mammals have adapted to diving and operating with limited air:

Stefansson — who died of a stroke at 82 (though, surprisingly, he lived longer than a lot of other VLC authors) — made the fatal assumption that land mammals and marine mammals are similar. They aren’t. They are entirely different, and the difference is tantamount to different species classification. The Inuit were exploiting unique carbohydrate properties in these marine mammals that aren’t found in land mammals.

It turns out that marine mammals that spend a good deal of their time diving to great depths have significant glycogen stores. Sperm whales make routine dives to 400 meters for 40 minutes and can reach a maximum depth of 2000 meters (6,560 feet, or 1.25 miles). Narwhals make some of the deepest dives recorded for a marine mammal, diving to at least 800 meters (2,600 feet) 18 and 25 times per day every day for 6 months, with many dives reaching 1,500 meters (4,900 feet). Narwhals have been recorded diving to as deep as 1,800 meters (5,900 ft, over one mile). In addition to making remarkably deep dives, narwhals also spend more than 3 hours per day below 800 meters — this is an incredible amount of time at a depth where the pressure can exceed 2200 PSI (150 atmospheres).

During their deep dives these marine mammals run out of oxygen and switch to their unique glycogen-based energy stores. They store large quantities of glycogen in very odd places, but it typically gets concentrated in the skin and organs. Researchers have discovered significant “glycogen pools” in the narwhal’s arterial thoracic retia. Ringed seals have “large quantities of glycogen” in a gelatinous material near their sinuses. A sperm whale’s blubber ranges from 8–30% carbohydrates, mostly believed to be glycogen. The hearts and brains of weddel seals have concentrations of glycogen that are two to three times that of land mammals. Furthermore; in marine mammals, these organs tend to be larger in proportion to the total body weight than in land-based mammals.

In 1973, George and Ronald wrote about the harp seal, “All the fiber types contained considerable amounts of glycogen…it is postulated that the seal muscle is basically geared for anaerobic use of carbohydrate as an adaptation for the animal’s diving habit.”

In a paper on diving marine mammals Hochachka and Storey wrote, in 1975, “In the terminal stages of prolonged diving, however, even these organs must tolerate anoxia for surprisingly long times, and they typically store unusually large amounts of glycogen for this purpose.”

Perhaps what’s most disappointing is that Stefansson never bothered to clearly explain the Inuit’s favorite sweet-tasting whale skin dish (muktuk), that was already known by scientists to be a carbohydrate-rich food. In 1912, the Journal of the American Medical Association (JAMA) had reported, “the skin [of the narwhal] contains a remarkable amount of glycogen, thus supplying sufficient quantities of a carbohydrate to cure the scorbutus. The walrus liver also contains much glycogen.”

So, this idea that we can compare glycogen content of a [grilled, braised, stewed, or otherwise thoroughly cooked, long after dead] cow or human to that of what the Inuit were eating is entirely misguided. We’re talking about marine animals that need large quantities of glycogen to complete their extended deep dives.

It’s well known that glycogen does not survive very long post-mortem. So, it was no coincidence that the Inuit often consumed glycogen-rich foods quickly and froze whatever they couldn’t consume. Peter Freuchen, a Danish doctor and member of the 5th Thule expedition based at Melville Peninsula from 1919-1925, wrote that when a whale was brought to the beach at Repulse Bay everyone feasted on large quantities of the skin until their jaws became too sore to continue.

After a hunt, seals are quickly cut to expose the internal organs. Kristen Borré writes in her 1991 report for the Medical Anthropology Quarterly, that “one of the hunters slits the abdomen laterally, exposing the internal organs. Hunters first eat pieces of liver or they use a tea cup to gather some blood to drink.” This was no coincidence. The parts of the animals with the most glycogen were eaten quickly.

At the time of death, the glycogen and free glucose in beef muscle contains approximately 6g of glucose equivalents per pound. As explained above, diving marine mammals have much more glycogen than land mammals. When we consider that the average Inuit consumed 5 to 10 pounds, or more, of raw fresh or flash-frozen meat per day, it should be clear that they were consuming a lot of glycogen.

But, of course, the Inuit consumed other carbs, too. They consumed berries, seaweed, nuts, corms, and tubers — such as yupik potatoes, boiled polysaccharide-rich seaweed, glycogen-rich winter mussels. See the Disrupting Paleo series for a more indepth discussion of these foods and their importance in the Inuit diet.

What about the glycogen in the foods that weren’t consumed rapidly? If only the Eskimos had access to extremely cold temperatures where they could rapidly freeze chunks of meats immediately after hunting… Hmmm… Kidding aside, the Inuit not only consumed fresh raw meat, blubber and skin that was rich in glycogen, but they also consumed it flash frozen — thus preserving and maximizing its glycogen.

Interestingly, Clarence Birdseye — who invented technology for “flash freezing” — learned about it from the Inuit. According to Wikipedia, “He was taught by the Inuit how to ice fish under very thick ice. In -40°C weather, he discovered that the fish he caught froze almost instantly, and, when thawed, tasted fresh.” He recognized immediately that the frozen seafood sold in New York was of lower quality than the frozen fish of Labrador, and saw that applying this knowledge would be lucrative.

While listening to the audio version of Endurance, about Shackleton’s failed attempt to cross the last uncharted continent on foot, I noted that the famished explorers found penguin liver surprisingly delicious.


  1. Michael Goldstein says:

    That’s not a particularly convincing article. I think Dr. Michael Eades further responded here:

    More important, to me, is that authors like the above seem to completely reject or ignore a vast amount of anecdotal evidence of people radically improving their health through all-meat diets.

    Amber O’Hearn (One of the best science blogs on the Internet)
    She lost a lot of weight and overcame acute mental health symptoms, which become present again if she eats any plants.

    Interviews and testimonials here:

    Thousands of people in this Facebook group:

    Owsley “The Bear” Stanley:
    He is better known as the LSD manufacturer and Grateful Dead sound engineer. He lived a long healthy life, the last 50 years of which were on an all-meat diet.

    Shawn Baker:
    This 50-year old orthopedic surgeon is also a lifelong athlete. He did much better on keto, but on the switch to all-meat, he has only gotten leaner and stronger. He is now leading an online study called “nequalsmany” to try to quantify this anecdotal data, with hundreds of participants.

    Other groups around the world historically ate all-meat diets, too.

    Also see this to help understand why vegetables are not necessary or even necessarily beneficial (and perhaps even very costly and damaging):

    So did the Inuit maybe have some carbs in their diet from the animal tissue they ate? Sure, I don’t know. I wasn’t there. Is there still substantial evidence from an incredible number of people’s real lived experience, including dozens of people I’ve personally witness transform? Yes.

    Honest scientists should be investigating all-meat diets with intense rigor, and the failure to do so is a tragedy for modern medicine.

  2. Michael Goldstein says:

    I should also mention these clinical case studies by the wonderful doctors at Paleomedicina in Hungary, who have successfully treated patients since 2011 using paleolithic ketogenic diets. In other words, all-meat or mostly all-meat.

    The Crohn’s case in particular experienced drastic setbacks when he consumed plant matter. This is a common pattern it seems with anecdotes of Crohn’s treatment online using low carb dieting.

  3. Jim says:

    There are genetic differences between Eskimos and other populations. What is the ideal diet for Eskimos is mot necessarily the ideal diet for Albanians.

  4. Ross says:

    I was nodding along with the Endurance author until:

    “…“the skin [of the narwhal] contains a remarkable amount of glycogen, thus supplying sufficient quantities of a carbohydrate to cure the scorbutus…”

    Ah, carbohydrate is a scurvy cure. I guess that’s why they call us “crackers”, eh?

    More seriously, glycogen formed by eating protein and gluconeogenesis as well as ‘eating carbs’. I don’t understand the vibe here. Sure, we should all store glycogen. And if we eat stored glycogen (internally or externally) we benefit. What’s all this hissing and spitting and quibbling for?

    Then I went to the site you linked, and watched the frothing, snarky, do nothing backbiters have at each other in comments and I figured it out.

  5. Isegoria says:

    To clarify, that wasn’t the author of Endurance, Alfred Lansing, making that comment about glycogen in narwhal skin curing “scorbutus”; that was from the cited century-old JAMA piece:

    121. Animal Remedy for Scorbutus in Greenland. — Bertelsen states that scorbutus is prevalent in Greenland, the very name Eskimo meaning “eaters of raw meat.” But, he adds, the natives have empirically found a remedy for the scurvy, namely, chewing the skin of the narwhal, the unicorn-whale. He describes research, with illustrations, showing that the skin of this fish contains a remarkable amount of glycogen, thus supplying sufficient quantities of a carbohydrate to cure the scorbutus. The walrus liver also contains much glycogen.

    I can see why we no longer call them Eskimos — although that etymology doesn’t seem to be correct:

    Two principal competing etymologies have been proposed for the name “Eskimo”, both derived from the Innu-aimun (Montagnais) language, an Algonquian language of the Atlantic Ocean coast. The most commonly accepted today appears to be the proposal of Ives Goddard at the Smithsonian Institution, who derives the term from the Montagnais word meaning “snowshoe-netter” or “to net snowshoes.” The word assime·w means “she laces a snowshoe” in Montagnais. Montagnais speakers refer to the neighbouring Mi’kmaq people using words that sound very much like eskimo.

    In 1978, Jose Mailhot, a Quebec anthropologist who speaks Montagnais, published a paper suggesting that Eskimo meant “people who speak a different language”. French traders who encountered the Montagnais in the eastern areas, adopted their word for the more western peoples and spelled it as Esquimau in a transliteration.

    Some people consider Eskimo derogatory because it is widely perceived to mean “eaters of raw meat” in Algonkian languages common to people along the Atlantic coast. One Cree speaker suggested the original word that became corrupted to Eskimo might have been askamiciw (which means “he eats it raw”); the Inuit are referred to in some Cree texts as askipiw (which means “eats something raw”).

    I’m shocked that a scientific journal referred to the narwhal as a fish.

    It’s fascinating to see that scurvy still wasn’t understood in the early 20th Century:

    In 1927, Hungarian biochemist Szent-Györgyi isolated a compound he called “hexuronic acid”. Szent-Györgyi suspected hexuronic acid, which he had isolated from adrenal glands, to be the antiscorbutic agent, but he could not prove it without an animal-deficiency model. In 1932, the connection between hexuronic acid and scurvy was finally proven by American researcher Charles Glen King of the University of Pittsburgh. King’s laboratory was given some hexuronic acid by Szent-Györgyi and soon established that it was the sought-after anti-scorbutic agent. Because of this, hexuronic acid was subsequently renamed ascorbic acid.

  6. Mike in Boston says:

    Matiej Ceglowski’s piece Scott and Scurvy, about how the relationship between ascorbic acid and scurvy was first discovered, and then essentially forgotten, should be required reading for anyone who thinks the history of science is one of never-ending progress.

Leave a Reply