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Dean Pomerleau

Are Humans Naturally Folivores, Frugivores or Faunivores?

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All,

 

Dr. Greger has an interesting video out today on "Paleo-Poop", discussing the evidence from fossilized human feces that our ancestors ate a very high fiber diet, > 100g of fiber per day vs. < 20g for most people today eating a standard American diet. This wasn't particularly new news to me, or to anyone reading this I suspect. 

 

But what I found most interesting about the video was at 2:30, where he discusses what was the likely source of all that fiber. In particular, whether ancestral humans were folivores (foliage / vegetable eaters), frugivores (fruit eaters) or faunivores (meat eaters). Its pretty clear from lots of evidence that we're not primarily meat eaters, and it has only been relatively recently in our evolutionary heritage that meat and other animal products became a large part of our diet. So we can knock faunivores out of the running - at least when considering deep evolutionary time.

 

What was most interesting was the distinction between the other two categories - folivores vs. frugivores. The evidence he shows in the video is from [1], and it is a plot of organism body size (x-axis) vs. density of gut mucosa (y-axis). Apparently the three categories (folivores, frugivores and faunivores) fall into distinct clusters. Here is the graph, with the range at which humans fall as the intersection of the horizontal and vertical lines with the label "Homo Sapiens":

 

Pkv5vFu.png

 

As you can see, humans of today fall squarely in the cluster of frugivores, which the authors interpret to indicate that our distant ancestors were primarily fruit eaters. 

 

Obviously we're omnivorous now, and have been for quite a while, especially since we expanded out of Africa into environments where fruit isn't readily available in large quantities or year-round, and since we develop cooking and other processing techniques to make meat (as well as other parts of plants) more digestible, and more palatable! But being a fruit-lover myself, I thought it interesting to know that at least our distant ancestors appear to have been heavy fruit eaters like orangutan (who apparently also love durian!), rather than folivores like gorillas. 

 

--Dean

 

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[1] Claude Marcel Hladik, Patrick Pasquet. The human adaptations to meat eating: a reappraisal. Human Evolution, Springer Verlag, 2002, 17, pp.199-206. Free full text

 

Abstract

 

In this paper we discuss the hypothesis, proposed by some authors, that man is a habitual meat-eater. Gut measurements of primate species do not support the contention that human digestive tract is specialized for meat-eating, especially when taking into account allometric factors and their variations between folivores, frugivores and meat-eaters. The dietary status of the human species is that of an unspecialized frugivore, having a flexible diet that includes seeds and meat (omnivorous diet). Throughout the various time periods, our human ancestors could have mostly consumed either vegetable, or large amounts of animal matter (with fat and/or carbohydrate as a supplement), depending on the availability and nutrient content of food resources. Some formerly adaptive traits (e. g. the “thrifty genotype”) could have resulted from selective pressure during transitory variations of feeding behavior linked to environmental constraints existing in the past. Key Words: meat eating, hominids, gut allometry, thrifty genotype

 

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Our ancestral regimen has been a subject of my recent pondering.

 

According to present knowledge it appears that the hominidae (great apes) started to develop about 16 million year ago.

The bipedals specieses have allegedly started to develop around 8 Mya. Bipedalism suggests a diversification from the arborean apes, in that probably less foliage and fruit, more tubers and wild legumes started to be consumed, the savannah being explored at farthest lenghts.

 

The above musing are not about folivore or frugivore, but on plant-based or omnivorous. It appears that most if not all primitive societies  recently studied (hunter-gatherers) included to some extent not negligible amounts of animal food (meat & insects). Even though fibre-rich, the diet is usually not plant-based but omnivorous. Now, paleolithic spans by definition from 2.6 millions to about 10000 Y ago.

 

Are the observed examples of hunter-gatherers a degeneration and why? Are they examples to follow or to avoid and why? Does the alleged omnivorism of paleolithic (which has not been proven in all areas and times) supersede the much longer frugivorism and foliagisms of hominids? What governs, the most recent mutations or the most basic, older-than-Miocene metabolic pathways? Are the recent (paleolithic onward) mutations significant in the dietary framework, since basic anatomy hasn't evolved much? Do such mutations come with a burden (increased illness hazard)?

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Dr. Greger's interpretation is straightforward: the hunter-gatherers were/are a degeneration of the primal hominids. Their priority is not longevity, rather reproduction, so their dietary scheme is geared toward acquiring caloric-dense foods which prevent starvation. In his opinion, our bodies have not adapted to the prevalent paleolothic diet, rather longevity and healthspan is compromised. The arguments appear valid, especially the ones on the adaptation to maximum conservation of cholesterol. Which however raises the question as to why some people do not develop high blood cholesterol even when eating lots of saturated fats.

 

Edited by mccoy

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Nice find mccoy, enjoyed the video.

 

I also like incorporating ancestral medicine as part of my thinking on health and wellbeing. I see it as a first pass inspiration of hypotheses, and then turn to the research literature to see what the data actually shows as first principals, intuition, and theory ( even based on fossil evidence and modern day approximations of hunter-gatherers) can only take us so far in making inferences to modern day homo sapiens and their respective environment / genetics / epigenetics.

 

Anscestral medicine can also add a little extra weight to the preponderance of research in influencing my conclusions too. For example, Michael Rae's https://www.crsociety.org/topic/11070-dha-accelerated-aging-hypothesis-validated/focuses on basic science concerns regarding excess PUFA intake above the essential fatty acid requirements. On the other hand while IOM sets some limit to PUFA by percent calories, epidemiologic data largely supports substituting SFA with PUFA to lessen risk for CHD and I am not aware of high quality RCTs in humans confirming elevated risk exceeding said thresholds... only more limited scope studies for example in other model organisms, or possible associations with certain cancers in humans and even this latter data is mixed. However by turning to ancestral medicine basic principals ( along with the aforementioned basic science, animal model, and limited human data) remembering our ancestors until very recently were not exposed to refined high PUFA seed oils - and seeing the limited % PUFA use by long-lived traditional societies and exponential increase in the use of PUFA coinciding with the chronic diseases of modernity, the ancestral medicine perspective encourages to be on the more cautious side, not only limiting to the range suggested by IOM, but seeking to avoid PUFA significantly beyond my EFA requirements while also keeping the omega-3 to omega-6 ratio closer to 1:1 to 1:4 range as well.

 

I enjoyed Dr. Greger's video. II think he is a well meaning very nice guy, but perhaps in part from the ethical vegan perspective, the data presented can be focused on those supportive of his paradigm, Same also for the analysis and its presentation. You may be interested in checking out the Ancestral Health Symposium. They do, as a whole can be sometimes ideological - e.g., those from the Weston Price camp, Dr. Cordain camp, "integrative medicine" camp, etc. However they are a lot more diverse and some very legitimate science can be found along with the anecdotal and biased. Keep in mind they are all-inclusive and not a "peer-reviewed" in the same manner as in scientific bodies, so the quality there is highly variable.

 

If you separate the wheat from the chaff - there are some interesting evidence-based presentations. For example, from AHS 2016

https://www.youtube.com/playlist?list=PLbhWKPDKXIEBBybYcY_jUQGE7S0KLgH5S

 

s couple of my favorites were:

 

1) Calorie intake by Dr. Guyenet PhD which cited some of the CR literature and underscored the key variables of BMI and caloric intake as key determinants of health and disease: https://www.youtube.com/watch?v=2xh8jb2euQ0&list=PLbhWKPDKXIEBBybYcY_jUQGE7S0KLgH5S&index=10

 

2) Food and Cognition by Dr. Blaisdell PhD which can be helpful when we provide advice on psychological barriers and tools for sustaining weight loss and maintenance: https://www.youtube.com/watch?v=js8MELGn3XM&list=PLbhWKPDKXIEBBybYcY_jUQGE7S0KLgH5S&index=7

 

BTW a good complement to #2 is the synopsis of #1's book, which is found here:

http://slatestarcodex.com/2017/04/25/book-review-the-hungry-brain/ [ his website: http://www.stephanguyenet.com/ ]

 

Some interesting pearls there: sadly for those seeking BMI decrease bland and less variety is better ( provided optimal nutrition of course )... hyoerpalatable foods raise BMI setpoint within its genetic/environmental leash, and mental devices such as mentally labeling categories of food as heathy vs. toxin notwithstanding reality being more nuanced - interesting fodder.

 

Other AHS videos depend on interest, for example Greenfield's "Biohacking vs. natural living" is germane to the practices of many forum participants and also found in the playlist above.

 

I went through about 80%+ of the videos available: type into google ahs16, ahs14, etc. and look for the youtube videos. There are even older ones on Vimeo. If AHS makes its way to the East Coast I may catch one, one day.

Edited by Mechanism

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Hi mechanism, I'm reading Guyenet's 'The  hungry brain' and he really makes a good work of illustrating the neurological aspects of bodyweight homeostasis.

 

I can also recognize some of the guys you cited like Ben Greenfield, others I'm going to look up. Many, as you say, support an omnivorous regimen but tend to have an unbiased view , like Chris Kessner, Coppola and so on. I know them from their podcasts.

 

My problem here is that the undeniable, indisputable fact is that our very ancestral blueprint is plant-based and diet has deviated from that only in the latest 10% or so of our evolutionary history. There have not been significant physiological changes either. So I would expect an overwhelmingly larger mortality ratio for carnivores-omnivores (those who deviate from the rule), that is an overwhelmingly lower mortality hazard ratio for vegetarians and vegans, but we know that it is not so. Even though ratios for some diseases are favourable.

 

Maybe there are other issues more important and related to the evolutionary dependance on plants which govern, like hormesis and xenohormesis. In this POW, even eating some meat and fish would not be a big issue if enough hormetic chemicals are ingested from the vegetable kingdom.

 

The overall logical framework is confused though. 

 

The hypothesis I favour presently is that of the existance of some degree of intelligent design, where evolution has been pushed (for humans) along the optimum of plant-based regimen, allowing some slack to tackle critical situations. This slack comes not without a price though, since it may increase the hazard of some disease.

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I tend to ignore all dietary gurus, and try to look at the evidence.

 

I also ignore those who believe that we should eat as did our paleo ancestors. E.g., we have the luxury of having

much more than adequate food available at all times, of varying quality; our ancestors didn't.

 

A good example: CR would be unthinkable for people constantly in danger of starvation. The evidence is high

that it is likely to increase our healthspan, and possibly even lifespan; so it's probably a good idea for our

practice -- but not for our paleo ancestors.

 

On the subject of vegan vs. plant-based, not-quite-vegan diets, I think that the evidence is that the latter is probably better.

 

(Although I wouldn't like to get into a polemic argument with the strong believers in veganism -- at least

they aren't jihadis!

 

:)

 

-- Saul

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I may be picking up "the hungry brain" myself - I enjoyed the review of it I linked to above, and appreciate your endorsement. After your post I picked up "Latest in Paleo" episodes - I listened to one before but got sidetracked and looks like interesting fodder.

 

I regard research and evidence as the ultimate arbitrator all other things equal. True enough the further back, the greater plant emphasis however:

 

1) evolution can proceed rapidly with disproportionate impact of very recent events in evolutionary history for that organism. Rapid evolutionary change via "punctured equilibrium" occur, and proportion of evolutionary time consuming relative proportions of plant vs animal matter does not necessarily follow with the same proportions being appropriate for the outcome of said evolution in said organism (us) today.

 

2) evolution governs maximal reproductive fitness, not necessarily maiximal healthspan and/or longevity. They often overlap, but not necessarily, and certainly not 100%

 

I do see a lot of value in ancestral medicine thinking for the reasons stated in my first post, but ultimately evidence from a wide variety of study methodology govern my assessment of the optimal diet and lifestyle ( along with some personalization for your genes, etc, when available).

 

Fortunately there is a lot of convergence of data on the benefits of a Whole Foods diet. None of the blue zones had a tremendous amount of animal sources ( or added sugars, processed foods, refined seed oils, etc) and a primarily plant-based diet is clearly the winner. However this can mean vegan / vegetarian with judicious supplementation ( esp B12) but can also mean omnivorous / Zone / Mediarranean, etc. diet with modest portions of seafood, etc. with optimal longevity as well. Low, but not necessarily no animal products is consistent across the Blue Zones, with only a subset of the seventh day adventists being strictly vegan. Results have been mixed on the vegan vs vegetarian or plant based flexaterian/pescatarian/ mostly plant-based omnivore relative health status ( with all other variables held constant), and differences in the health outcome of one over the other have gemreraly been marginal in the best studies.

 

So any of these diets including vegan can produce great outcomes in the observational data. I deeply respect the

Vegan choice and way of life, I simply do not feel it has to represent based on current quality data the optimal diet per se. There are many other reasons to choose vegan including ethics, the environment, and taste. This is a choice we all face. For health, there are many roads to Dublin.

Edited by Mechanism

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Fortunately there is a lot of convergence of data on the benefits of a Whole Foods diet. None of the blue zones had a tremendous amount of animal sources ( or added sugars, processed foods, refined seed oils, etc) and a primarily plant-based diet is clearly the winner. However this can mean vegan / vegetarian with judicious supplementation ( esp B12) but can also mean omnivorous / Zone / Mediarranean, etc. diet with modest portions of seafood, etc. with optimal longevity as well. Low, but not necessarily no animal products is consistent across the Blue Zones, with only a subset of the seventh day adventists being strictly vegan. Results have been mixed on the vegan vs vegetarian or plant based flexaterian/pescatarian/ mostly plant-based omnivore relative health status ( with all other variables held constant), and differences in the health outcome of one over the other have gemreraly been marginal in the best studies.

 

So any of these diets including vegan can produce great outcomes in the observational data. I deeply respect the

Vegan choice and way of life, I simply do not feel it has to represent based on current quality data the optimal diet per se. There are many other reasons to choose vegan including ethics, the environment, and taste. This is a choice we all face. For health, there are many roads to Dublin.

 

Mechanism, as you say there is evidence that an omnivorous, healthy diet containing little animal foods is correlated to the exceptional longevity which occurs in the blue zones. That's a fact.

 

What I'm less and less convinced about is the validity of the hunter-gatherer model as a reference of an healthy diet.

 

As Guyenet states in the 'hungry brain' book, survival of the species (reaching reproductive age and reproducing) is the priority of primitive society, non longevity. Health and longevity are not evolutionary imperatives of primitive societies, reproductive health is.The hunters-gatherers known by anthropologists inevitably eat animal foods. Moreover, they intuitively follow an algorithm based on the caloric density of foods and the caloric expense to obtain such foods.

In other words, the priority of hunter gatherers is quantity of energy obtained in relation to quantity of energy expended,  the priority is calories dense foods, animal or vegetal it doesn't matter, but usually animal is calorie-dense so they do tend to grab meat and fish whenever they can. This does not consitute a causal element of health, rather a survival imperative, whose long-term effects on health are irrelevant to that system because they do not mind about longevity.

 

The takeaway lesson to me is that the hunter gatherer is not a valid model to follow. Paleo guys may muse 24/7 about the dietary regimen of hunter gatherers, but that's mainly irrelevant to our situation where the feeding algorithm should rather be reversed, eschewing calorie-dense food (animal based prevalently) and acquiring calorie-sparse ones (plant based prevalently).

 

The cardiovascular and metabolic health of hunter gatherers may be caused not by diet, rather by many other factors, the brutal selection operated by the harsh environment being a fundamental one in my reasoning. No weak persons with flawed cardiovascular system are apt to survive in those difficult conditions. Those who survive are genetically and inherently healthy and robust. And they pretty much have to move around and physical exercise is a necessity, not a luxury.

 

Last but not least, a little cited aspect of hunter gatherers is that they are afflicted by intestinal parasites carried by the flesh they eat. Not an attractive idea to me.

Edited by mccoy

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Hi McCoy, I could not agree with you more: evolutionary imperative is not synonymous with health and longevity per se but rather optimal propagation of genes. They may align, but not necessarily and may also conflict.

 

This is not controversial at all in truly academic circles, and I have certainly seen the distinction blurred, not infrequently in parts is the lay paleo community. There is nothing new here. Even Rosendale ( and I do not consider myself paleo nor prescribe to his low carb model of health which does not seem to acknowledge adequately that medium or high carb if low GL and high nutrient can be as or more consistent with optimal health as his own low carb "formula" for health ) acknowledges the tension between maintenance&repair vs growth & reproduction.

 

In my estimation, ancestral medicine is helpful primarily for hypotheses that require validation or refutation - as a launching pad for research in living populations and other forms of empirical evidence. This perspective also suggests more scrutiny for dietary and lifestyle approaches that have not stood the test of evolutionary time - but so-called "unnatural" interventions ( such as various medications many of which have saved millions of lives!) are not necessarily harmful and may be net beneficial and need to be assessed to determine their true impact on health.

 

This is one reason I look at natural, ideally genetically heterogenous populations, and better yet RCT trial evidence consistent with better animal models in assessing the value of various lifestyle interventions in promoting optimal health.

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