Uh-Oh Paleo: Grains Were Part of Hunter-Gatherers’ Diet


As a Crossfitter, I have to hear all about the benefits of “Going Paleo” at the gym. While I love the premise of muscle confusion to increase strength, agility and overall fitness, I can’t find any good reason to recommend a protein-packed, hunter-gatherer diet. Since there’s no evidence that our ancestors lived long enough to experience the chronic diseases like cancer and heart disease that we get, I’m not sure how proponents of the diet make that case. The one benefit of the Paleo Diet that I have seen with others is that it makes you realize all the added sugars and overly processed carbohydrates that we eat every day.

Luckily, mounting research from anthropologists is proving that our ancestors’ diets included ancient grains and probably alcohol as well. New research reported in the Proceedings of the National Academy of Sciences in December reported that DNA from human teeth remains found from the hunter-gatherer era reveals that our ancestors did, in fact, eat grains, among many other foods that we previously thought they did not consume.

Will this new news finally knock some common sense into my X-fit friends who swear by their meat-, nut- and veggie-based diets?

The Paleo Premise
The premise of eating “Paleo” or the “caveman” or “hunter-gatherer” diet, is to mimic the diet of our ancestors ate from the Paleolithic era until the agricultural revolution began about 10,000 years ago. As hunter-gatherers, it was thought that we subsisted on grass-fed meats, game, free-range birds, fish, fruit, veggies, and nuts. That means no dairy products, no processed foods, no sugars, no grains, no alcohol.

Problem is, the Paleo diet has been made popular by minimal research and is more hype than anything else. I also believe it’s completely unsustainable for most individuals. Maybe that’s why it’s promoted by exercise specialists who graduated from the “school of hard knocks” rather than nutrition professionals.

When you break down a typical Paleo diet, it gets the majority of calories from animal foods and just under 50% of calories form plant foods. The diet is higher in protein (almost twice as much) as we currently recommend in the Dietary Guidelines and fat intake is higher, although the fats are primarily healthy omega 3s and other unsaturated fats.

I’m all for diets that get rid of excess processed foods and help to eliminate the “junk” in our diet. Paleo, however, is just not based in credible science and until I see evidence as to why we can’t enjoy whole grains and some lean dairy products, I’m sticking with my 21st Century approach to healthy eating by:

Eating a primarily plant-based diet

Including lean proteins, especially from seafood, poultry, lean meats, nuts, seeds and beans

Enjoying whole grains as primary source of grains

Minimizing added sugars, sodium and sat fat

Using olive, peanut and canola oils as my major fat sources


  1. Nyx says

    Hi, Julie, I just stumbled here by accident and was curious. I do not claim to know the “real” answers to what our paleolithic answers ate, but I think the study you are citing does not actually help. The study you have linked to is talking about the neolithic period. Drs. Eaton and Konner (medical and anthropology professors at Emory University), at least, are looking at much older period of time than the article you cite, but also, I think their point is that humans ate a certain way (and here I am not saying they are correct, but this is their point, I think) — that they ate a certain way for over a million years before people starting eating legumes and grains, which happened about 10,000 years ago (or perhaps a little longer ago than that). they make the point that 10,000 years is not long enough to evolve much, but in the article you cite, I don’t think the civilization examined was 10,000 years old, or maybe just a little older than that. fyi, there is a different study that found evidence of grain eating from about 30,000 years ago, so there are weaknesses to be sure in the paleolithic diet theory, but I think we would need evidence of people eating grains much longer ago than that before it would actually undermine their argument. They have a more recent article, by the way, in a journal called Nutrition in Clinical Practice, which is available online here: http://ncp.sagepub.com/content/25/6/594.full. These doctors are professors in the medical school, by the way, so I would not be too quick to shrug off what they say.

  2. vbsc says

    10,000 years might not seem like a lot. But consider hunter-gatherers who scavenged in groups of 50. Then agriculture starts and you can have thousands of people occupying the same land.

    If you have chance X of a mutation occurring, then with 50 people it takes much longer for a mutation to occur than if you have a population that is 20x larger. Once a mutation that confers survival benefits occurs, it takes a surprisingly short amount of time, a few generations, for a mutation conferring a 5% advantage to propagate through the population.

    So yes, 10,000 years is relatively not a lot of time. But how many man-years was that? If we spent 100,000 years as hunter-gatherers in bands of 50 people, and just 10,000 years engaged in agriculture, then that is 100,000*50 versus 1000*10,000. 5,000,000 man years vs 10,000,000 man years. *More* evolution could occur in those 10,000 years than in those 100,000 years.

    And has.
    You ought to read the 10,000 Year Explosion.

  3. Donna says

    You might be interested to read The Perfect Health Diet by Jaminet & Jaminet (2 PhDs in science). They mention that grains and legumes can be problematic because they evolved to survive the digestive tracts of mammals and still be viable. Good for the grain/legume;bad for the mammalian gut. They present tons of research / references to support a 15-20% protein, 20-25% starchy carb, 50-60% fat diet with as many green veggies as you like (which are converted to fat in the gut). They argue that fat is the preferred source of energy for all cells of the body except brain/neurons so might as well eat it directly as it does not take metabolically damaging pathways to digest (as do excess starchy carbs and protein). 600 calories per day combined protein and starchy carbs (glucose not fructose); no added polyunsaturates (PUFAs) which are damaging; monounsaturates are fine (MUFAs), saturated is fine; minimal fructose which is fruit and sugars (and of course no high fructose corn syrup products).By weight, the diet is 2/3 plant, 1/3 animal. Results would be more energy, muscle, higher body temp which fights pathogens, reduced body fat and cravings, better lipid profile, good blood sugar / insulin regulation, etc.

  4. Val Jones says

    The problem I have with Crosfitters (and I crossfit) and Paleo is that sometimes with some people it comes across as the only way to go and if you aren’t Paleo you don’t make the cut. I learned long ago not every thing works for every person. I tell my athletes, find something that works for YOU. And yes, cut back on processed foods, duh. That is a no-brainer. Thanks for letting me rant.

  5. david b says

    Id argue that everyones time would be better spent trying to disprove their current beliefs.

  6. Pauly says

    “Since there’s no evidence that our ancestors lived long enough to experience the chronic diseases like cancer and heart disease that we get…”

    The “30-year life expectancy” used in such arguments is not a tangible defense. You’re using the term “Life Expectancy” interchangeably with “Lifespan”.

    “Life Expectancy” includes such things that modern medicine has significantly reversed. Things like infant mortality, influenza, smallpox, and many other epidemic diseases that have better control of in modern times.

    Infant mortality alone skews the numbers. In 1900, the infant mortality rate was around 170 per 1,000 births. In 2000, it was about 7 per 1,000 births. The average U.S. life expectancy in the year 2000 was 77 years. A 0.7% IMR in 2000 means that the average Lifespan was about 78 years.

    Using a 78 year Lifespan, a 16.5% IMR in 1900 brings the Life Expectancy down to about 65 years of age. In other words, if a baby survived the first year, they could likely expect to live to 78.

    Now let’s go back to the year 1850, when we have records showing IMRs as high as 350 per 1000 for some populations (and likely higher for others we have no records for). A 35% IMR brings the Life Expectancy down to about 51 years of age. But again, that’s based on everyone else living to an average of 78 years.

    That’s just an example of how Infant Mortality brings down the Life Expectancy. I haven’t even considered deaths caused by epidemic diseases, war, or Celine Dion. And those are U.S. figures. Infant mortality could be as much as 60% higher in populations without access to the medical care we had even back then.

  7. says

    First off, you need to keep in mind that the span of time that the modern grain has existed within human history is but a sliver of the overall timeline. To compare the two, you can think of it as placing a yardstick on a football field. It’s but a fraction. The whole point of Paleo is to get people to stop eating processed crap and stick to real natural foods. It’s what our ancestors bodies are programmed to eat through billions of years of evolution. The shorter lifespans were, generally, due to a much more hazardous environment with predators and natural dangers. A small cut could have been enough to take out a caveman in some cases. Obviously things are a little different today.

    As for higher intakes of protein, from my years of dietary research, I’ve found that one of the biggest factors in most successful diets/nutritional plans is a higher protein intake. There’s just no real way to gain excess fat from it and it’s much more satiating and filling over time than high carbo meals. Helps with insulin resistance as well.

    By the way, I’d say be careful of suggesting canola oil and other vegetable based processed oils. They not only heat that stuff up to an unnatural temperature, but also run a powerful industrial solvent through it to minimize rancid smells and other leftovers. Even if you get cold pressed, keep in mind that you’re greatly increasing the intake of omega 6, leading to more inflammation.

  8. says

    Um, the paleo (hunter gatherer) mode of eating was dominant for millions of years; the alleged ‘paleo’ grain eaters quoted in the scholarly article in this blog are from withing the age of agriculture, the past 10,000 years, and that is NOT true paleo. The blog thesis is thus flawed and fails.

  9. Rob says

    I completely agree with the comment of Pauly about lifespan and life expectancy. There’s a lot of research in the area of what our ancestors ate. And yes, they consumed quite a bit of fat and protein. However, we as modern homo sapiens have to be careful into not drawing conclusions about what the ancestral diet and ours. There are several variables we need to keep in mind when looking at the data:

    1) Our genetics have remained relatively constant over millennium without too much change. The few identified mutations seem to be largely regulatory changes such as lactase. Also, compared to our ancestors, our generation produces higher copies of a-amylase (to break down starches) in saliva.

    2) We lead a sedentary lifestyle compared to our ancestors. We work 8hrs/day in the office, usually behind a desk. Our ancestors worked the same amount, but the work involved strenuous activity.

    3) Our ancestors’ usual daily energy intake was ~3,000 calories per day. Ours may be a little lower, but we don’t burn our calories the same as they did (due to sedentary nature of our lifestyle)

    4) Modern day diet is packed with dense energy foods. This was not the case with our ancestors. meaning, for every kilo of material consumed, today’s food contains much more energy, which we have to metabolize or otherwise turns into stored reserves of energy. This creates the problem of obesity that we see today. The wild foods consumed by our ancestors lacked this energy density and were lean meat and this feature in combination with slow transit time of food through the digestive system invariably served as a natural check to obesity.

    5) when we talk about our ancestors and their diets, it would be prudent to be specific. Which ancestors, what region, what climate. Eskimos ate predominantly high fat/protein diet, because plants did not grow in those cold and high altitude climates. Does that mean that someone living in the equator should adopt a similar diet? absolutely not. The !Kung (in Botswana, Nambia) had a diet which was comprised of 35% animal food and 67% plant food. It is interesting to note that the 67:35 (plant:animal ratio) is almost equivalent to a 1:1 calorie diet which Boyd Eaton have suggested (Proc Nutr Soc, 2006. Vol 65(1): 1-6).

    6) Our ancestors consumed a massive amount of fiber. 120+ g/day was the norm (depending of which ancestors). We don’t. The average westerner’s diet is ~15g/day. Most people equate fiber with constipation, but it goes well beyond that (not going to discuss this here though).

    There are a lot more issues the way we, as modern day H. sapiens extrapolate dietary data from our ancestors daily routine. But the fact of the matter is (in my opinion) that our ancestors consumed a more carb than meat (note: the carb was wild fruits and vegetables, not processed carbs of today). The meat that was consumed was mostly lean, and high in w-3 PUFA and lower in w-6 PUFA. These were not cooked to death (as in our modern diet) which contribute to why we have such high rates of colon cancer.

    Some paleo proponents go so far as to recommend high cholesterol diet in our diet without putting the appropriate pieces together. Sure, our ancestors ate animal foods that contained cholesterol, but what we fail to realize that their diet also contained high amounts of fiber from wild sources which have little phytic acid (120+ g/day compared to the dismal 15 g/d we get today). It is this fiber that interferes with absorption of bile in the intestines, leading to excretion of bile in feces, leading to production of more bile salts and LDL receptors, which in turn bind and “pull” cholesterol from blood.

    If we blindly just consume more cholesterol rich diets without a balanced view of the diet (such as high fiber, etc), we’re not doing ourselves or our health any justice.

  10. Jay says

    Rob, re: cholesterol… I didn’t think dietary cholesterol was given much attention anymore, even by mainstream nutrition. Maybe you’re referring to saturated fat? Not that I think mainstream nutrition has that right either, but at least it maintains it’s notoriety as having some effect on blood cholesterol levels. And why do you think the meat consumed was mostly lean? It seems logical that humans would’ve eaten the whole animal, especially the nutrient rich organs, which are of course higher in fat. Seems doubtful they would have exclusively eaten lean cuts of meat, and though wild animals might be leaner than feed-lot grain fed animals, they’d still be storing fat.

  11. Grace says

    I think the real problem is nowadays everyone has a PhD, everyone is a nutritionist, everyone is a fitness instructor and everyone thinks they know everything and put it all over the web with all their qualifications which they’ve received online in 30 days. I have no idea why we can’t eat grains, all I know is I’m Italian and I love pasta and I couldn’t live without it! Lol

  12. Rob says

    Hello Jay,
    I wasn’t referring to saturated fat. Sure sat fat does effect cholesterol depending on person and makeup and lifestyle (+ a slew of other factors). I am referring to actual dietary cholesterol (as opposed to de novo synthesized chol). I think of all the diet fads out there, the paleo is the most logical and sensible one (within context). But, my view on paleo diet is: just because my ancestors did it, doesn’t mean I have to. Also, who are my ancestors? That question has to be answered from POV of short term and intermediate term evolutionary perspective and also be put in context of “MY” present lifestyle. Without context, it would be foolish of me to consider one diet versus another.

    Why do I think that the animals our ancestors ate were lean? Well, for one thing most animals we consumer are domesticated, sedentary one (cows, sheep, etc), farm raised. Our ancestors hunted their food (wild animals) and wild animals are much leaner. The fat content is higher on w-3s than today’s farm-raised animals.

    Eating a whole animal is right, but they did it to derive every ounce of energy out of food (including anything edible). Our bodies are built with the evolutionarily instincts to survive bouts of starvation so every little bit counts. This survival advantage allowed our ancestors to avoid starvation when food was scarce. Today, with access to food 24/7 (well…most developed world), our instincts have not waned, but we eat more and do less. I wouldn’t eat liver just because our ancestors did. Liver is essentially the filtration system of the body. Sure, it may be packed with a some nutrients, minerals etc, but this is also where bile acids and toxins are recycled, made and stored. Nor would I eat the intestines of an animal (for obvious reasons, ;-)). Now, if I were stuck in the wild for months at a time with no access to food, I certainly would go for anything edible to survive…that will include liver, intestines, etc…

    Unfortunately, I do not have the luxury of space to discuss this topic in too much detail, but I will be starting a blog soon, where the goal is to bridge the knowledge gap between consumers and the science of health and nutrition. I think that by distilling scientific and medical concepts into straightforward and accessible explanations and framing them in proper physiological and evolutionary context, we will change the dialog between people and nutrition.


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