Carbs (not Meat) Were Crucial Factor For Developing Big Brains

Discussion in 'Scientific Studies' started by haidut, Aug 7, 2015.

  1. haidut

    haidut Member

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    The Paleo community is ablaze as a result of this news article. The study claims that even though meat may have kickstarted the process of developing big brains, it was carbs that were crucial for the sustained development of a big brain and the intelligence associated with it.
    I think points 1) and 2) from the article below are particularly important. I know several new moms who were on the Paleo diet while pregnant and their kids all have some language development problem - i.e. seem to be behind their "cohort" by about a year.


    http://www.sciencedaily.com/releases/20 ... ceDaily%29

    "...Hardy's team highlights the following observations to build a case for dietary carbohydrate being essential for the evolution of modern big-brained humans:

    (1) The human brain uses up to 25% of the body's energy budget and up to 60% of blood glucose. While synthesis of glucose from other sources is possible, it is not the most efficient way, and these high glucose demands are unlikely to have been met on a low carbohydrate diet;

    (2) Human pregnancy and lactation place additional demands on the body's glucose budget and low maternal blood glucose levels compromise the health of both the mother and her offspring;

    (3) Starches would have been readily available to ancestral human populations in the form of tubers, as well as in seeds and some fruits and nuts;

    (4) While raw starches are often only poorly digested in humans, when cooked they lose their crystalline structure and become far more easily digested;

    (5) Salivary amylase genes are usually present in many copies (average ~6) in humans, but in only 2 copies in other primates. This increases the amount of salivary amylase produced and so increases the ability to digest starch. The exact date when salivary amylase genes multiplied remains uncertain, but genetic evidence suggests it was at some point in the last 1 million years.

    Hardy proposes that after cooking became widespread, the co-evolution of cooking and higher copy number of the salivary amylase (and possibly pancreatic amylase) genes increased the availability of pre-formed dietary glucose to the brain and fetus, which in turn, permitted the acceleration in brain size increase which occurred from around 800,000 years ago onwards. Eating meat may have kick-started the evolution of bigger brains, but cooked starchy foods together with more salivary amylase genes made us smarter still."
     
  2. Such_Saturation

    Such_Saturation Member

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    Re: Carbs (not meat) were crucialf factor for developing big brains

    The real issue with the Paleo community is that they go ablaze over a news article :ss
     
  3. jyb

    jyb Member

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    Re: Carbs (not meat) were crucialf factor for developing big brains

    I think our big brains are interesting in that they might explain the odd situation where we can use both (or either) fats or carbs for energy. Breast milk for example has significant quantities of both carbs and fats. The reason for fat seems clear, as without it we would die quickly whenever running out of glucose or protein. So the ability to use glucose in addition or even as replacement to fat could be related to the human brain.
     
  4. EnoreeG

    EnoreeG Member

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    Re: Carbs (not meat) were crucialf factor for developing big brains

    I’m glad you posted this haidut. Rather than driving a wedge between paleo and non-paleo clans, it might be a means to bring understanding to both sides.

    I’m not an expert on Paleo, but I think it suffers from the same misinterpretation as The Atkins diet: People take (and eat) what they wish to. They ignore the rest of the protocol.

    Just like your thread title implies, the typical Paleo advocate easily shuns dairy and grain and embraces meat. But she totally ignores what she doesn’t really care for but was probably eaten by paleolithic man in even greater amounts than the touted starches. And that is above ground, fibrous leaves and fruits. No different than a cross section of great apes. Typical omnivore food. But there was that balance of minerals, enzymes, phytonutrients and yes, fiber, that could not have been in just meat, nor even in just meat and tubers.

    So the only reason the Paleo community is ablaze is that they must be predominantly followers of, and ignorant believers in, only their treasured part of the Paleo diet. Kiss them off. Typical followers.

    But I’ll reason that just because meat (alone) doesn’t make the human brainy, it doesn’t mean that necessarily just the simple concept of “carbohydrates” does impart the human brain with the qualities we are so proud to possess. Or, to be Paleo accepted, it doesn’t mean that the combination of just head-to-tail meats plus any carbohydrates, are going to account for the evolution of the large brain.

    From all I’ve read, evolution has been continual. That means humans not just in competition with the elements and other animals, but with other humans for their territory and their foods. Thus, the humans with the best foraging and hunting plans, and thus the best food supply survived over the more stupid humans. For that reason, I’d guess that, just as today, humans who received the best nourishment from a broad spectrum of plant material, were healthier, and bore more intelligent offspring.

    It happens that all these little, but not insignificant, nutrients that come from plants (and not just starchy tubers) are bound up in cell walls that contain cells that are primarily carbohydrate, and not protein and not fat.

    This does not make the carbohydrate the winning formula, or the Crucial Factor as your title declares. If I get anything across in this little rant, it would please me to get across the idea that this issue, as people start to delve into it and contribute to it, should not be CARBS vs MEAT.

    On an in-depth study of nutrition, and evolution, etc., that carb/meat battle is rather silly. Not that I’m saying this subject is silly, nor your thread title. That is all fine to get peoples’ attention! But a lot more is involved in nutrition, and in what makes a healthy human brain, than just the balance of macronutrients.

    So to further this discussion a little, I’d like to introduce a few more studies on prenatal and neonatal nutrition. One can review these in brief form by reading this one blog post by good old Edward Edmonds, who himself says nothing. He’s just regurgitating the text from multiple studies showing what type of nutrition a human (sometimes a rat, yes) gets during different stages of prenatal and postnatal life. Turns out it is quite fat oriented. But proteins, sugars, and fats are all brought into perspective, both in how they are used by the neonate and by the mother, as things change during the different trimesters of pregnancy.

    Neonatal ketosis
     
  5. EnoreeG

    EnoreeG Member

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    Re: Carbs (not meat) were crucialf factor for developing big brains

    Well said! I was typing my reply to haidut as you put this out, but for more along your lines, check the references in the link at the end of my post, jyb.
     
  6. Westside PUFAs

    Westside PUFAs Member

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    The Importance of Dietary Carbohydrate in Human Evolution

    If you're anti-starch then don't read this. :)

    New study that just came out with 266 references.

    http://www.jstor.org/stable/10.1086/682587

    "We propose that plant foods containing high quantities of starch were essential for the evolution of the human phenotype during the Pleistocene. Although previous studies have highlighted a stone tool-mediated shift from primarily plant-based to primarily meat-based diets as critical in the development of the brain and other human traits, we argue that digestible carbohydrates were also necessary to accommodate the increased metabolic demands of a growing brain. Furthermore, we acknowledge the adaptive role cooking played in improving the digestibility and palatability of key carbohydrates. We provide evidence that cooked starch, a source of preformed glucose, greatly increased energy availability to human tissues with high glucose demands, such as the brain, red blood cells, and the developing fetus. We also highlight the auxiliary role copy number variation in the salivary amylase genes may have played in increasing the importance of starch in human evolution following the origins of cooking. Salivary amylases are largely ineffective on raw crystalline starch, but cooking substantially increases both their energy-yielding potential and glycemia. Although uncertainties remain regarding the antiquity of cooking and the origins of salivary amylase gene copy number variation, the hypothesis we present makes a testable prediction that these events are correlated."

    "We agree with Wrangham (2009) that the reduction in gut size is more likely to have occurred due to a gradual replacement of fibrous plants by higher energy-yielding plant foods, including starchy tubers."

    "We contend that in terms of energy supplied to an increasingly large brain, as well as to other glucose-dependent tissues, consumption of increased amounts of starch may have provided a substantial evolutionary advantage to Mid-to-Late Pleistocene omnivorous hominins."

    "However, we propose that high-starch plant foods would have been a plentiful, reliable, and important part of the diet."

    "The rapid growth in hominin brain size during the Middle Pleistocene will have required an increased supply of preformed glucose. Such increased demands can be met through a range of biologically and culturally driven dietary adaptations. Noting that there is considerable overlap in date estimates for the origins of controlled fire use and the origins of AMY1 CNV, we hypothesize a gene-culture coadaptation scenario whereby cooking starch-rich plant foods coevolved with increased salivary amylase activity in the human lineage. Without cooking, the consumption of starch-rich plant foods is unlikely to have met the high demands for preformed glucose noted in modern humans. Likewise, the improved accessibility of starch to α-amylases through cooking would, in turn, have led to an increased advantage for high levels of salivary amylase expression, particularly in infants. Carmody and Wrangham (2009) highlight the increased speed of digestibility and consequent energy gain provided by starch that has been thermally processed; however, AMY1 expression is also required for this to be effective. In addition to the increased energy availability from starch, other advantages of the coevolution of cooking and AMY1 expression include a reduction in chewing time, increased palatability and digestibility of polyphenol-rich plant foods, and improved reproductive function; a reliable supply of glycemic carbohydrate is likely to have sustainably supported fetal growth, provided the extra caloric intake needed during lactation, and improved infant survival. The regular consumption of starchy plant foods offers a coherent explanation for the provision of energy to the developing brain during the Late Pliocene and Early Pleistocene while the development of cooking, and a concomitant increases in salivary amylase expression, explains how the rapid increases in brain size from the Middle Pleistocene onward were energetically affordable."
     
  7. Suikerbuik

    Suikerbuik Member

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  8. tara

    tara Member

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    Sure, being omnivorous gives us a wider range of possible foods, and that's really useful for survivial.

    But IIRC from breastfeeding class, human milk has a lower proportion of fat and a higher proportion of sugar than most mammals, including many herbivores. In the context of breastfeeding class, this was presented as a reason to feed often, not on some previously popular infrequent feeding schedule that would keep all but a few babies too hungry. This seems to fit with us evolving to be in regular contact with mother during infancy, which presumably has advantages in terms of transmitting culture, and I imagine also supports a higher metabolism and a larger and faster developing brain, and maybe other factors.
     
  9. pboy

    pboy Member

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    definitely carbs year round availability was probably the main thing, and specifically denser sources rather than water rich fruits...honey could have played a factor, but more likely it was tubers. Perhaps gelatin from scavenged carcasses or iodine rich sea/freshwater things like oysters and small fish or whatever, or seaweed could have helped also, but definitely not muscle meat
     
  10. schultz

    schultz Member

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    Let's not forget that fresh meat contains carbohydrate. Oysters have more carbs than protein. The inuit have a diet that is as high as 20% carbohydrates from the glycogen in the animal because it's fresh, and they live in an area that has almost year round snow. Humans with year round access to plants, etc. could have a much higher carbohydrate percentage if they were consuming things like oyster, tubers and freshly killed meat.

    On a side note: Apparently fermenting meat can hydrolyze some of its protein in carbohydrate.

    "Eskimos actually consume more carbohydrates than most nutritionists have assumed. Because Eskimos frequently eat their meat raw and frozen, they take in more glycogen than a person purchasing meat with a lower glycogen content in a grocery store. The Eskimo practice of preserving a whole seal or bird carcass under an intact whole skin with a thick layer of blubber also permits some proteins to ferment into carbohydrates."
    Yiu H. Hui (February 1985). Principles and issues in nutrition
     
  11. tara

    tara Member

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    I really notice the difference between fresh liver and older liver - fresh lightly cooked liver tastes sweet.
     
  12. mt_dreams

    mt_dreams Member

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    Mating with higher intelligent beings seems to have worked for the lighter skinned crowd.
     
  13. pboy

    pboy Member

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    actually I'm thinking, the main thing that seperates humans from other apes is our ability to procure larger amounts of selenium and iodine...that's pretty much it, so it had to have been some kind of meat I guess, well...wheat and rice and oats (and a few nuts) have selenium but its unlikely that was the first thing people went for, I guess its kinda obvious...it was sea things, probably near the coast, which might also explain the lack of humans having hair. In some other cultures, theres like ancient practices of woman diving for shellfish and stuff and seaweed and things of the sort, like they do remarkable things even in really cold water with just their bare hands and breath, no real tools..i mean you never know though actually, it could've been scavenged or hunted things on land...but it seems like it would've had to be more concentrated sources. For sure though there had to have been an abundance of carbs accompanying this. I guess the moral is...who cares!
     
  14. Such_Saturation

    Such_Saturation Member

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    It's almost inspiring how quickly it turned tin-foil and racist :ss :10
     
  15. mt_dreams

    mt_dreams Member

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    29.9 outta 30 ... i'll take it.

    I'm talking big brains, not necessarily smarter, though I'll call them regionally to not get anybody all hot and bothered. Light skinned was a bit misleading too, as it probably also includes some Asian hobbit lovers.

    So I rephrase,
    Mating with larger brained beings seems to have worked for the non black Africans. Hobbit lovers not included.
     
  16. pboy

    pboy Member

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    also milk fits every requirement necessary for higher brain growth, so it easily could have been that, but supposedly big brains evolved way before milk drinking
     
  17. schultz

    schultz Member

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    A lot of the weird tropical fruits have not been analyzed and could contain selenium (though I guess it depends on the soil). A single Cherimoya for example has about 100% of the RDA for selenium according to Cronometer.

    In the Weston Price book he talks about some place in Africa where the women would travel down to the Ocean (I think it was near the Nile) and burn this certain plant and then consume the ashes which would prevent goitre. This was an iodine source for them.

    Another Weston Price anecdote talked about aboriginal Australian kids who attended this "white children's" school. They wouldn't bring a lunch, but instead when lunchtime came they would just dive into the ocean and catch lobsters and such.

    I'm sure way back when people did all sorts of creative things to survive.
     
  18. pboy

    pboy Member

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    yea so I guess its hard to say one thing or another was the single factor, just probably figuring out clever ways to get in more nutrition overall, the backbone just being adequate carbohydrates but then from there probably more of the hormonal boosting factors...selenium and iodine id suspect mostly

    that's awesome too about the kids diving for lunch, in parts of I think it was Thailand or one of those indo Asian countries the kids would, during regular public school, go outside and catch tarantulas and large insects, bring them into the cafeteria to be cooked then eat them, lol. That was their meat
     
  19. schultz

    schultz Member

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    There is a BBC documentary series called "Human Planet" and in one episode some South American kids go out and find tarantulas to eat because their families don't have enough food. They cook them on sticks and put a little chili on them or something.

    In the same documentary a guy climbs this super tall tree to get honey. If he fell he would probably die and there were no branches for like a hundred feet. Apparently his wife wanted honey, so he basically had to do it lol. The narrator explains how important the honey is as a food. Another episode shows some northern peoples (possibly inuit) catching these birds with a long net. He catches them and puts them into a seal stomach or something, then rubs fat all over it and puts rocks on top then leaves the whole thing there for like 3 months.

    Very good documentary. It's mostly about traditional peoples, how they survive and some of their customs.
     
  20. EnoreeG

    EnoreeG Member

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    Selenium shows up in most foods. Not just animals or fruit. The important factor is the soil (and then after that, the food chain). There are many areas in the world where the soil is deficient, but a few areas where it is in such excess that you will get selenium poisoning if you are eating all local foods, as would have the early humans.

    In the USA there are many areas which have dangerous levels of selenium in the soil, and animals (more than humans) get poisoned from grazing on the selenium rich vegetation.

    Selenium by county in the USA

    In the "rich" counties, one might try to eat a good percent of foods that are non-local, to avoid the excess.

    You can also search and find selenium distribution across the globe. Don't think you are necessarily short on selenium if you just eat plants.

    Also, certain plants (crucifers and allium) are "accumulators" of seleniumm and will be quite high in selenium compared to other plants if the soil is rich in it.
     
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