mTOR and protein threshold

[Ioanna]

At the moment I have borrowed the book "primal body, primal mind" by Gedgaudas.  Wondering  your thoughts on this (from p 208 if anyone has the book):

"Much as insulin serves as a sorto fo default 'sugar sensor' and leptin serves as our body's 'fat sensor', mTOR serves as our body's protein sensor,  monitoring the availability of protein, or amino acids (particularly the bransched chain amino acids), for growth and reproduction.  It is also influenced by insulin levels and is part of a related metabolic pathway.  When protein levels are detected that exceed our basic mainteneance requirements, this up-regulates the mTOR patheway, stimulatin cellular proliferation.  Increased insulin also has this effect and the mTOR protein belongs to waht is known as the P13K pathway that is activated by insulin, nutrients and growth factors. mTOR has a central role in the regulation of cell growth and protein synthesis.  It essentially activates our reproductinve capacity. Again, cellular proliferatin occurs mainly under three circumstances: reproduction (DNA replication), growth, as, for example in children, ... and cancer. "

She then goes on to say that caloric restriction may offer a protective effect against cancer.  That caloric restriction inhibits mTOR pathway while "boestiy, or positive engy balance, enhances siganling through these pathways, leading to cell growth, proliferation and survival. If, however, the dietary protein level stays below this threshold ancient mechanisms kick in that are designed to help us outlive an 'apparent famine', which then shuts down cellular proliferation and up-regulates, instead, repair and regeneration. It signals and effort to keep us healthy enough, long enough so that our cells may reproduce another day. That's what we want. We want just enough protein to meet the demands of our own repair, regeneration and basic maintenance needs that can extend our own longevity, enhance our own health and possible even reverse signs of aging... but not so much that we up-regulate mTOR. "

She then goes on to say that this 'threshold' for protein is (in most adults) 45-53 g, maybe 60-70 in an extremely athletic or large person  or someone particularly depleted nutritionally.


I don't think she is in favor of carbs, she says they are not an essential nutrient, but she includes vegetables, salads, cheese, etc in her daily menus at the end of the book. I think her recommendation is to eat this much protein and the rest of the calories fat.

I don't like this book very much.  There is nothing original, it was not edited well, reads like she rushed to put something out that is just a compilation of sally fallon/weston price and few others... not an original thought in the entire book (or at least what I read of it) and poorly written/edited IMHO.  There is a bibiliography section at the end, but with the exception of one chapter, she did not reference as she went along which is entirely poor and disrespectful writing IMO, isn't that plagarism??  I haven't gone through her bibliography, so that's why I haven't provided any references to the above. 

Okay, anyway, wondering your thoughts on this 'protein threshold' as dictating by mTOR signaling pathway that promotes cell growth.
 

[TylerDurden]

Well, I mentioned earlier a different explanation for why caloric restriction works, namely that eating less (cooked) foods at greater intervals between meals gives the body more time to get rid of the heta-created toxins present in cooking, thus extending lifespan.

As for the protein issue, I have to admit to a great deal of skepticism re this. I mean tribes in the wild didn't artificially measure their protein-intake and given that in those Palaeo days fat-intake would have been significantly lower than today(ie no very fatty grainfed meat available pre-agriculture), their protein-intake would have presumably been  higher than the very low figures the  current protein-limit-theories mention.

[Guittarman03]

I have read that our cells have DNA instructions that they can only divide and reproduce for so long before they cannot anymore.  I think this is one of the hurdles with genetic cloning, and why clones have short lives. 

If you are an elite athlete, constantly regenerating cells, or if you are eating alot and putting on weight, I can see how this would decrease longevity. 

I have to say I'm suspect of the 40-50g a day of protein.  Seems pretty low, especially in the absence of carbs. 

Lol, the article actually makes me want to eat more consistently more often so I can keep up the mTOR. 

[invisible]

As for the protein issue, I have to admit to a great deal of skepticism re this. I mean tribes in the wild didn't artificially measure their protein-intake and given that in those Palaeo days fat-intake would have been significantly lower than today(ie no very fatty grainfed meat available pre-agriculture), their protein-intake would have presumably been  higher than the very low figures the  current protein-limit-theories mention.

That's a silly thing to say. They had access to the entire animal. Their fat intake was beyond doubt higher. The only meat available in supermarkets is the separated lean muscle tissue. Inuit ate ~80% fat through instinct, and so would of native American eating wild bison. I'm eating more fat now eating only grass fed meat

Article provides interesting points.

[TylerDurden]

That's a silly thing to say. They had access to the entire animal. Their fat intake was beyond doubt higher. The only meat available in supermarkets is the separated lean muscle tissue. Inuit ate ~80% fat through instinct, and so would of native American eating wild bison. I'm eating more fat now eating only grass fed meat

Article provides interesting points.

That' not true. Looking at supermarkets and butcher's shops, the fat on grainfed meat is extensive, despite some occasional cutting off of fat. By comparison, wild game meat(and grassfed meat) is much leaner than domesticated grainfed animals as it takes several years longer for the animals to build up sufficient fat-layers while on a 100% grass/herbs diet than on a grain diet. As a result of this, several grassfed beef farmers have bitterly complained to me about the shockingly draconian EU directives which forbid farmers slaughtering organic-raised  past the time limit of 30 months of life, as they say it's not reallylong  enough to build up sufficient fat on the animal via a grassfed diet. Another rawpaleodieter(from the rawpaleodiet yahoo group), "Gary Via", who is himself a grassfed meat farmer, has confirmed this point.

Another consideration is the fact that the grassfed animals tend to lose fat-layers over winter and then have to build them up again from spring onwards. That's the reason several UK grassfed meat farmers have given me on several occasions when they said I would have to wait till Easter before they could slaughter some new beef.

And, fat on a grassfed animal, other than the fat on the muscle-meat, isn't present in great amounts. The fatty brain is thrown away due to regulations versus BSE(as well as the fatty eyeballs), then there's the suet around the kidneys and the marrow and tongue. Other than that and the muscle-meat fat, there's not much else.

Lastly, people on SAD diets definitely do eat vast amounts of fats, given dairy consumption etc. Palaeo peoples, by contrast, had to eat wild game meat from animals suffering famine/undergoing heavy exercise or during winter when fat-layers were much lower etc.

As for the Inuit, many tribes had unusual access to blubber-bearing animals so that their fat-intake was unusually higher than other native tribes further south.

[invisible]

Tyler what do you estimate the fat percentage of a Lion's diet is.

Doesn't matter if a wild animal is more lean. Hunters ate what they wanted, even if it meant killing more animals and throwing away the lean. Australian Aboriginies ate extremely high fat eating kangaroos which are lean relative to other mammals. They chose the fattiest and discarded the lean.

[Josh]

What do you think about the idea that there was more fatty megafauna around?

[carnivore]

What do you think about the idea that there was more fatty megafauna around?

What is clear is that during ice ages, when vegetable was few, our ancestors found enough fat to survive!

[TylerDurden]

What do you think about the idea that there was more fatty megafauna around?

That is unlikely, Most current studies of what Palaeo man ate, suggest a very wide range of foods being eaten such as fowl , seafood and both small and large game. Generally speaking, the smaller the animal the less percentage of fat it will have in relation to its body, so that eating only small animals would mean very little fat in the diet.

[TylerDurden]

One of the few interesting points made by nutritionists is that modern humans  have unusually strong cravings for fats and sugars. They explain this by pointing out that fats and sugary foods were a (relative) rarity in the Palaeolithic, so that Palaeo humans craved them in particular, as a result.

[TylerDurden]

Tyler what do you estimate the fat percentage of a Lion's diet is.

Doesn't matter if a wild animal is more lean. Hunters ate what they wanted, even if it meant killing more animals and throwing away the lean. Australian Aboriginies ate extremely high fat eating kangaroos which are lean relative to other mammals. They chose the fattiest and discarded the lean.

You're forgetting that palaeo tribes did not live in a land of plenty. They normally had to take what they could get, lean or otherwise. So, choice was only possible during the good times. Plus, I'm sceptical re claims that palaeo peoples simply threw away the  meats. I'm sure they stored meats as high-meat(like the Eskimoes) rather than discarding valuable protein. In short, hunter-gatherers are opportunists interested in survival rather than monitoring their protein-intake religiously.

[Josh]

I looked up lions - the male eats mostly the hindquarters and the females and cubs eat the internal organs. Not sure how much that means to us though 

[TylerDurden]

I looked up lions - the male eats mostly the hindquarters and the females and cubs eat the internal organs. Not sure how much that means to us though  

Lions are carnivores, we are omnivores(albeit meat-leaning). I doubt that carnivores are adapted to eating only fatty meats as then those carnivores which concentrated on preying on smaller animals would suffer due to lack of sufficient fat - yet there's no evidence of rabbit-starvation among wild animals, to my knowledge.

[Raw Kyle]

That is unlikely, Most current studies of what Palaeo man ate, suggest a very wide range of foods being eaten such as fowl , seafood and both small and large game. Generally speaking, the smaller the animal the less percentage of fat it will have in relation to its body, so that eating only small animals would mean very little fat in the diet.

Regardless of what studies say about what humans ate, there were more larger animals around before humans started hunting species to extinction in most of the continents.

[Neone]

I do not believe that you need LOTS of fat or you will die. The grassfed bison that I get do not have very much fat on them compared to the meat on them. Are you saying that if grassfed bison was the only available meat around that you and the people who helped you kill the bison that you are sharing the whole thing with (so you are only getting a portion of the scarce fat), that you are all going to die horribly because nature did not provide for you?

[Raw Kyle]

The thing is that the meat you get is not representative of the whole animal. I'd like to see a whole carcass, cut up, with lean and fat compared. It would obviously be more fat than you see in the grocery store or at a typical butcher, because modern consumers don't demand fat they demand lean.

[Josh]

FWIW, I asked a bison farm about suet and they said they can't supply it because the bison are too lean.

[TylerDurden]

I do not believe that you need LOTS of fat or you will die. The grassfed bison that I get do not have very much fat on them compared to the meat on them. Are you saying that if grassfed bison was the only available meat around that you and the people who helped you kill the bison that you are sharing the whole thing with (so you are only getting a portion of the scarce fat), that you are all going to die horribly because nature did not provide for you?

If this is addressed to me, I should make clear that I am merely pointing out the flaws in the high-fat claims made by Fallon and co and have suggested that given current evidence , palaeo diets were lower in fat. I do not believe that the lower amounts of fat found in grassfed meats, and particularly in wild game, were an issue or caused rabbit-starvation as fat contains something like 2.5(?) times as many calories as protein/carbs so even a little fat would ultimately constitute a sufficient  percentage of the diet to avoid rabbit-starvation(assuming a zero-carb diet for Arctic-sited  palaeo tribes with no access to carbs)* Of course, a non-ZC Palaeo diet consisting of some carbs as well would avoid the rabbit-starvation issue altogether.

[Raw Kyle]

FWIW, I asked a bison farm about suet and they said they can't supply it because the bison are too lean.

Do they slaughter their animals very young? Also, is that meant to mean that the farmer is claiming there is no suet on the animals?

[Josh]

Dunno mate..just got told that they're lean animals and suet can't be supplied. make of it what thou wilt

[yon yonson]

i've found that lots of farmers don't really know what suet is. they just think it's any large amount of fat on the animal. the farmers i worked with this summer didnt know there animals had suet around the kidneys until i asked about it. then they asked the butcher if they could save some for me. anyways, that's probably what's going on with the bison ranchers you're talking about

[TylerDurden]

i've found that lots of farmers don't really know what suet is. they just think it's any large amount of fat on the animal. the farmers i worked with this summer didnt know there animals had suet around the kidneys until i asked about it. then they asked the butcher if they could save some for me. anyways, that's probably what's going on with the bison ranchers you're talking about

You see this is the big problem today, Now we have everything sanitised and controlled by the State so that there are ever fewer abattoirs/slaughterhouses in the UK than ever before, and only a few farmers still slaughter their cattle at home. The result is most farmers I speak to haven't a clue when I talk about buying adrenal glands or lungs or whatever. Some were even reluctant to sell me raw organic ox liver because they felt there wasno market for it(most people apparently find it tasteless in cooked form).

[TylerDurden]

Do they slaughter their animals very young? Also, is that meant to mean that the farmer is claiming there is no suet on the animals?

I should mention that, in the UK where Josh is, it's customary to slaughter all cattle, even grassfed, at the too young age of 30 months. It's a stupid EU regulation pushed through after all that mindless hysteria re BSE. The authorities simply ignored the fact that the BSE crisis was siolely due to intensive farming/grainfeeding etc. and applied the ban everywhere.

[van]

with the Inuit, it's easy, as Tyler mentioned there is so much fat in the animals/fish they hunt.  Plains Indians.  I have read where they hunted only those that had fat stores.  Then there's the idea that they made pemican for when fat (or meat) was scarce.  And I have heard from Bison farmers here in the US that you can go out and shoot a bison.  The next day or even right after and shoot another.  They have no fear of what just happened.  Don't know if this would translate to Bison way back,  but maybe.  Non Indians killed them by the thousands.  I have seen pictures.  So maybe the plains people did select what they needed from the animal and learn how to preserve the rest.  If they had to live off of deer, that would  be a different story.       
 
    The other important notion that Rosedale repeatedly points out;   that nature doesn't intend to propetuate longevity.  Just life that goes on long enough to pass along the skills for the next generation to go on.   We might want to look to nature as a building block and to others who might be more interested in longevity for our missing answers.     I used to write to Charles on his site, after he would tell me about the perfect health of the plains Indians,  that,  'Maybe,  I wasn't there,  I never witnessed in what fashion those Indians died, or at what age'.  They might have had all kinds of damaged systems within their bodies from overeating of meat or insufficient fat with their meat, or from cooking or over cooking their meals.    I think in time with current interests in a low to zero carb diet like Rosedale, Harris, Lex, etc. etc. that some form of truth may bear out?

[William]

    The other important notion that Rosedale repeatedly points out;   that nature doesn't intend to propetuate longevity.  Just life that goes on long enough to pass along the skills for the next generation to go on.   We might want to look to nature as a building block and to others who might be more interested in longevity for our missing answers. 

Pointed out by a paleoanthropologist was that the survival of able-bodied and mentally competent elders gives a huge survival advantage, both in acquiring food and coping with life in general.

Rosedale makes the common mistake of confusing man with human.