It looks like our ancient ancestors ate a low-carb diet

I make no secret of the fact that I’m a believer in the concept that our diets should, for the most part, emulate those of our ancient ancestors. The diet we ate for long periods of our evolution is likely the diet we are best adapted to and is the best for us. There’s abundant scientific evidence to support this concept, by the way, and most agree that it makes sense too.

The thing is, do we actually know what our ancient ancestors ate? There is evidence that prior to about 10,000 years ago, our ancestors were hunter-gatherers. For the vast majority of our evolution our diet was devoid of many modern-day foodstuffs including bread, pasta, breakfast cereals, milk, refined vegetable oils and refined sugar. ‘New’ foods eaten in the last 10,000 years make up about 75 per cent of the typical calories consumed in a ‘standard Western diet’.

Until recently, in evolutionary terms, the human diet was ostensibly made up of ‘primal’ foods such as meat, fish, shellfish, eggs, fruits, vegetables and nuts. However, it stands to reason too that the relative proportions of these foods in the diet would have varied considerably as a result of availability and necessity.

Our ancestors evolving away near the equator would, likely, have decent access to plant-based foods including fruit and vegetable matter. But the further away we get from the equator towards the poles, the less plant matter there is, and the more reliant on hunting for meat and fish our ancestors would have been.

One way of getting some insight into the details of our evolutionary diet is to examine the diet of modern hunter-gatherers. Probably the best source of relevant data here is known as the Ethnographic Atlas. Within it can be found dietary information from 229 contemporary hunter-gatherer societies. This data was recently analysed by two German researchers in an effort to gain insight about the carbohydrate content of primitive, hunter-gatherer diets [1].

The percentage of calories contributed by carbohydrate varied from about 3 per cent to around 50 per cent. It will come as no surprise that they discovered that percentage of the diet coming from carbohydrate was higher in populations close to the equator than those further away. The most common percentage among all the groups came in at around 20 per cent.

Official recommendations are normally that about 60 per cent of the calories we consume should come from carbohydrate. That’s actually higher than the most carbohydrate-rich hunter-gatherer diet of all, and about three times the average carbohydrate percentage in such diets. The authors of this study conclude, ‘…the range of energy intake from carbohydrates in the diets of most hunter-gatherer societies was markedly different (lower) from the amounts currently recommended for healthy humans.’

It’s perhaps worth mentioning too that not only has the quantity of carbohydrate changed in percentage terms, but its quality too. Long gone are the days when our carbohydrate mainly came in the form of fruits and vegetables including tubers. Now, we consume much more in the way of grain-based products, many of which have been refined, refined sugar and fruit that has been cultivated to be sweeter than fruit found in the wild.

Evolution allows some adaptation over time, of course, but there are limits. Adaptation is generally slow to come, and many of us run the risk of consuming carbohydrate beyond what is good for us in terms of both quality and quantity.

There problems with such a diet are manifold, I think. We can have the blood sugar disruption and surges of insulin to start with. Peaks of blood sugar encourage damage in the body through a variety of processes including inflammation and glycation (binding of sugar to tissues). Highs of blood sugar can lead some time later to lows which can trigger all manner of symptoms such as hunger, food cravings, mental fatigue, mood change and waking in the night.

The surges of insulin that comes in response to gluts of blood sugar can predispose us to problems such as weight gain, heart disease and type 2 diabetes.

Of course one way out of this would be to reject conventional nutritional advice on carbohydrate consumption, and keep the diet as ‘primal’ as possible.

References:

1. Ströhle A, et al. Diets of modern hunter-gatherers vary substantially in their carbohydrate content depending on ecoenvironments: results from an ethnographic analysis. Nutr Res 2011;31(6):429-35.

29 Responses to It looks like our ancient ancestors ate a low-carb diet

  1. Cordier 11 October 2011 at 1:38 pm #

    The pivotal point: dietary ADDICTIONS.
    I decided to give up my main dietary addictions, wheat and cheese one month ago.Now I eat gluten free bread(40% carbohydrates instead of 75% in wheat bread))as a substitute for wheat bread,and yaourts for cheese.It’s the first time I am starting really to lose weight without feeling withdrawal symptoms or compulsions!.Above all,I realize now how many foods I didn’t eat in the long run before(and yet I am sixty):green leafy vegetables,potatoes,quinoa,buckwheat,onions,leek, kale,radish,beetroot,even rice etc.A new world of flavors,textures,recipes.Daily.And with gusto.I am happy.Let’s hope that it lasts!

  2. DoctorM 11 October 2011 at 4:12 pm #

    I agree with Cordier. I think that avoiding wheat, modern cows milk, sugar and refined grains and oils as well as all processed foods and additives is sufficient for a healthy diet – but eat all the things that Cordier lists and all other natural or near natural wholefoods.
    Modern foods have been developed from ancient foods but this equally applies to animal foods as well as fruit. Much ‘supermarket’ pork (and beef in US) and chicken for example are fed unnaturally on refined grains and pork is unnaturally fatty as a result. Our ancient ancestors certainly did not eat bacon or fatty meat – wild meats are low in fat. I don’t understand why Dr John does not appear to have taken this on board in his recommendations. I think meat derived from animals fed on refined grains is just as unhealthy as the refined grains themselves.

  3. Chris 11 October 2011 at 8:01 pm #

    “Our ancestors evolving away near the equator would, likely, have decent access to plant-based foods including fruit and vegetable matter. But the further away we get from the equator towards the poles, the less plant matter there is, and the more reliant on hunting for meat and fish our ancestors would have been.”

    I have sometimes wondered if the nutritive properties of cold-water fish somehow compensate for environmental aspects, including potentially available food types, of inhabiting latitudes further from the equator or sub-tropics.

    “It’s perhaps worth mentioning too that not only has the quantity of carbohydrate changed in percentage terms, but its quality too. Long gone are the days when our carbohydrate mainly game in the form of fruits and vegetables including tubers. Now, we consume much more in the way of grain-based products, many of which have been refined, refined sugar and fruit that has been cultivated to be sweeter than fruit found in the wild.”

    We have advanced or progressed over the course of evolution to include plant food types in the diet that would not be viable without that we applied some pre-consumptive process to the food type. Examples include milling and cooking. Grass seeds (cereal grains) would simply not be viable fodder in their natural form. Hence we ‘mill’ them, ‘refine’ them and ‘cook’ them. Likewise there are many tuberous food types (or underground storage organs, ‘USOs’) that we would find indigestible unless we cook them.

    There are expediencies which make inclusion of these food types attractive to consume and attractive to ‘sell’; yet the expediencies many find most agreeable are not ones associated with the nutritive make up of these foods nor with preserving the nutritive integrity of the various food types that make up the diet.

  4. Chris 11 October 2011 at 8:04 pm #

    “Grass seeds (cereal grains) would simply not be viable fodder in their natural form”

    .. and of course they are truly nutritionally unbalanced ‘fodder’ when refined. (!)

  5. Beth@WeightMaven 12 October 2011 at 1:48 am #

    The study you cite notes:

    “Hunter-gatherer diets were characterized by an identical carbohydrate intake (30%-35% of the total energy) over a wide range of latitude intervals (11°-40° north or south of the equator).”

    But whether you are talking 20% or 30%, that’s still a substantially higher amount of carbs than the typical low-carb promoter advocates.

    So while I agree that this is considerably less than the 60% of energy for the typical Western diet, I think it’d be more correct to say our ancient ancestors likely ate a lower carb diet rather than a low carb diet (mostly depending on latitude).

  6. Robbo 12 October 2011 at 7:08 am #

    In terms of our evolutionary heritage, what hunter-gathereres eat near the poles is irrrelevant, since our forebears lived only in africa until c 100 thousand years ago.

  7. John Briffa 12 October 2011 at 11:48 am #

    Robbo

    My understanding is that our migration from Africa started a long time before you suggest.

    But let’s not quibble about it, because the evidence suggests considerable evolutionary adaptation to our environment in the form of skin colour. Chances are that there’s been considerable adaptation to other environmental influences, like food, too.

  8. John Briffa 12 October 2011 at 11:53 am #

    DoctorM

    I think meat derived from animals fed on refined grains is just as unhealthy as the refined grains themselves.

    We’ll have to agree to disagree on this one. Personally, I’d take grain-fed beef over white bread any day of the week.

    Also, is your objection to the amount of fat that might be found in meat, or the type of fat (or both)?

  9. DoctorM 12 October 2011 at 1:52 pm #

    Dear Dr John,

    With regard to US type grain fed beef BOTH Type – high in omega 6 and low in omega 3 AND amount – much higher than our ancient ancestors.

    I can’t see how one can describe US type grain fed beef (let alone modern grain / soy fed pork and bacon) as paleo or primal. In England, lamb and beef have some probability of being nearer to primal as they is a good chance that some or all of their diet was grass – so there is a case for eating these and I do eat them.

    But I think intensively farmed unnaturally fed pork and chicken are to be avoided even in UK. Most worrying are pork which is incredibly (unnaturally) fatty these days and bacon which is a modern product.

    Surely you’d recommend a mixed whole grain wheat free muesli with nut and seed over a plate of bacon which is emphatically not paleo or primal and much more modern than whole grains ?

  10. John Briffa 12 October 2011 at 3:44 pm #

    DoctorM

    I can’t see how one can describe US type grain fed beef as paleo or primal.

    I didn’t describe it as ‘primal’, I said I’d take it over white bread.

    But I think intensively farmed unnaturally fed pork and chicken are to be avoided even in UK.

    I agree with that.

    Surely you’d recommend a mixed whole grain wheat free muesli with nut and seed over a plate of bacon which is emphatically not paleo or primal and much more modern than whole grains ?

    I’m not sure I would, actually, particularly if someone had an allergy/intolerance to the grains in the muesli and/or was sensitive to carbohydrate or had metabolic syndrome or type 2 diabetes.

  11. Paul Anderson 12 October 2011 at 6:14 pm #

    Whilst I agree with some posters that meat derived from grain fed animals is not equivalent to wild meats it also worth pointing out that hunter gatherers preferred to eat the fatty meats and organs of animals: brain, liver, kidneys, marrow and offal ,etc, in preference to the leaner muscle.

    I suspect fat would be valued precisely because it is a dense source of calories. As an added bonus they would have got a healthy dose of fat soluable vitamins and some vitamin C from the liver.

    I personally suspect that grass fed meat is preferential to grain fed but either I suspect is better than healthy wholegrains.

    Paul.

  12. DoctorM 12 October 2011 at 6:56 pm #

    Dr John

    I think we are not too far apart.

    My focus is on keeping near nature rather than low carb – so I advocate a diverse diet of near natural foods (vegetables, fruits, nuts, seeds, fungi, seaweed, herbs, spices, fish, meat, poultry, legumes, grains other than wheat, milk other than modern cows) including some whole grains even oats and rye which arguably have some health benefits – but one certainly should not obsess on grains.

    As regard carbs, I think inability to tolerate carbs – which after all have been a major part of the human and pre-human diet – probably results from poor micronutrient status due to gross overconsumption of modern refined foods. If one has reached this state then a recommendation to eat significant amount of carbs may not be appropriate. However I do not think that inability to tolerate carbs is a very natural human state and that if one eats or has eaten a high nutrient natural diet then carbs should be able to be consumed without raising insulin levels excessively and without engendering obesity. We may have to agree to differ on this. Oh and I certainly cannot recommend modern bacon which, being processed, is even worse than intensively farmed pork.

  13. Chris 13 October 2011 at 5:06 pm #

    “Whilst I agree with some posters that meat derived from grain fed animals is not equivalent to wild meats it also worth pointing out that hunter gatherers preferred to eat the fatty meats and organs of animals: brain, liver, kidneys, marrow and offal ,etc, in preference to the leaner muscle.”

    Those remaining people still living a traditional subsistence, ie. those who are the subject of the Ethnographic Atlas, demonstrate a willingness not to waste anything. They approach matters that all of a kill is valuable. They may show a preference to utilise organ meats first because organ meat may spoil more quickly than muscle meat, and they may find that organ meats of a fresh game kill are not so resistant to mastication as the muscle meats can be. Also, if the diet is relatively marginal, and if there is a direct association between physical effort and a ‘meal’, then fatty foods, or fatty parts of foods, become economically expedient.

    Something I find interesting, though, is that some such peoples can provision their needs in about three to four hours of enterprising behaviour each day. I work about 12 hours a day within a society that has an energy budget vastly exceeding those of traditional peoples – could anyone explain?

  14. Chris 13 October 2011 at 6:03 pm #

    “However I do not think that inability to tolerate carbs is a very natural human state and that if one eats or has eaten a high nutrient natural diet then carbs should be able to be consumed without raising insulin levels excessively and without engendering obesity.”

    It is by chance that I came to entertain and appreciate that ecologies are founded upon the economies involving the trade of energy and nutrients. The trade began deep in the heart of the universe but continues within the natural ecology of the Earth, to an extent within agriculture, with the growing of, and trade in, food.

    It is also by chance that I was directed to appreciate that our economy, and our economic activities, can been seen to have features of ‘ecolologies’ about them.

    To my mind, the human origins program is revealing much about the evolution of our particular species and much about probable co-evolution with our diet. Long term trends and changes, arising not at all by intent, turned out to be physiologically expedient where the form of a modern human is concerned. The problem for modern human, though, is that the ecology of money, now tends to determine what choices, activities, and methods are considered ‘expedient’.

    I can see where you’re coming from DoctorM; there are times when my own beliefs would have been in step with your own. From an academic or intellectual point of view centred around the science of ‘nutrition’ I could not disagree with you with the certainty of believe myself informed or correct. However, I see food as a missing link in evolution. I ‘see’ the presence of evolution at work behind sociological and socio economic outcomes. It is from this point of view that my mind and my conscience confers validity and merit upon the study and the interpretation of Dr Briffa.

    If more Doctors and the powers that oversee them better understood the ecology of money and the constituent activities that make up GDP we’d have healthier populations and better methods of resolving health conditions. If we better understood the expediencies at work in natures’ economies as opposed to being obsessed with a surrogate and un-natural medium of exchange we’d have greater security, an improved sense of well-being, and, just possibly, fewer conflicts. A willingness to utilise a more economically democratic medium of exchange, as opposed to persisting with bank-issued, debt-founded money, could certainly result in fewer conflicts of interest. I am excluding yourself from judgement, DoctorM, but the health industry is an industry generally beset with conflicts of interest is it not?

    Never underestimate the power of money or the power of the ecology of money, for the ecology of money renders high carbohydrate diets expedient, but not necessarily healthy.

  15. Angie 14 October 2011 at 9:55 pm #

    This doesn’t surprise me. One of the River Cottage foragers points out how difficult it is to find carbohydrates if you forage, so hunter-gatherers would be likely to have had considerably less of it in their diets. I’m also with Paul on the fats, the need for which is much more obvious in populations who are either exposed to the elements or with substantial amounts of physical activity.

  16. DoctorM 15 October 2011 at 1:45 am #

    I think fats are a very important part of the human diet. They should be consumed by eating natural wholefoods containing fats, such as nuts, seeds, oily sea fish, meat from wild or naturally fed animals especially offal, oily fruits such as avocadoes and olives and grains such as oats – these are all included in the list of natural foods to be eaten which I gave above. However one should avoid eating isolated fats, extracted fats, refined fats, processed fats, synthetic fats or fats from unnaturally fed animals such as intensively farmed pork or bacon. The modern western diet is obsessed (for commercial reasons) with ‘empty calories’ from refined and processed foods and food from animals which have been fed unnaturally. Just look in any supermarket – aisle after aisle of processed breakfast cereals, milk products, crisps, alcohol, cakes, bread from refined wheat and added chemicals, intensively farmed meat, tinned foods, convenience foods etc etc – virtually none of which can be regarded as close to nature.
    Keep close to nature, eat as diverse a range of near natural foods as possible, avoid refined and processed foods, additives, and do not obsess with any one food.

  17. hilda glickman 15 October 2011 at 11:11 pm #

    DrM, I agree with you. I used to think that consuming olive oil was a good idea but now I think that we should only eat oils in the actual olives or nuts, ie in the foods themselves rather than what is extracted from the foods . This is because we get too much fat whe it is extracted, it could rancid but also because in the wholefood there are cofactors which help us process these oils.

  18. DoctorM 17 October 2011 at 12:12 pm #

    Hilda
    Exactly right !
    Regards

  19. Deborah Booth 17 October 2011 at 9:10 pm #

    Living here in Galicia, North Spain it is wonderful to see the cows/cattle eating grass all year, only supplemented with hay and haylage. We are lucky to be able to buy cheese, real milk and yoghurt from an organic farm, and eat locally grown grass grazed beef .

  20. DoctorM 17 October 2011 at 11:39 pm #

    Deborah,
    You are indeed lucky. The problems of industrial milk are many : selection by breeding of cows to produce allergy inducing type A1 casein rather than type A2 casein which is dominant in the milk of all other mammals, pasteurisation, homogenisation, skimming which distorts the nutitional profile, non-organic feeds, feeding on grain rather than grass which boosts omega 6 at expense of omega 3 and – in US practice – feeding on refined and processed corn and soy, ubiquitous use of genetically modified feed (corn and soy) – very risky, use of growth promoting hormones – very risky, use of antibiotics because cows are not healthy – very risky, and reduction of mature lifespan from years to a few months ! I hope these latter ‘advances’ do not come to UK. Such industrial milk is poles apart from the type of milk that you are lucky enough to be able to get. And I have not even started to list how milk is processed into other so called ‘foods’ !
    The best cows milk I can find in UK is unhomogenized (yet pasteurised) whole milk from Jersey and Guernsey cows which still produce milk with mostly type A2 casein – otherwise known as Gold Top. Milk has changed so much over the last hundred years – I suppose you can regard milk as a microcosm of the industrialisation of foods. The more common a food is the more industrialised and further from nature. Milk may not be paleo/primal but I think both milk and grains (provided they are from the near nature end of the range) can sensibly form part of a modern diet provided that one does not obsess on them.

  21. Sue 19 October 2011 at 4:32 am #

    John, I would appreciate it if you would give your take on what John McDougall believes, ie, that although we may have evolved on the foods you recommend, they are not the foods which will give us a longer, healthier life. He apparently believes that any food eaten before the last 10,000 years is unhealthy, and a starch-based diet is best. Having tried that for several years, while not only NOT losing weight, but suffering two auto-immune diseases, I now enjoy great health and have lost the desired weight on a primal diet. His web page is so seductive though, that I would love to have your thoughts.

  22. Kirsty 19 October 2011 at 6:45 pm #

    DoctorM – I don’t understand your objection to bacon or natural animal fats. At it’s simplest, bacon is just pork belly and salt. I make my own (and I do use saltpeter) or buy good quality bacon from a butcher. I agree with Hilda’s comments to avoid eating extracted fats but I wouldn’t avoid eating fatty meat, it’s the most natural fat available. As my celtic ancestors would have had little access to avocados, olives or any other oily fruits (unfortunately for them) I can’t see how those foods could be the main source of such an important part of our diet (fat).

  23. Robin 19 October 2011 at 7:11 pm #

    Here in wild West Wales, I can buy organic whole pasteurised milk from M & S and Tesco. Not Tesco’s own brand of organic milk which is a mixture of past/homog milk, but Calon Wen – a local farmers’ cooperative. Great stuff.

  24. DoctorM 19 October 2011 at 11:34 pm #

    Robin. Yes – I’ve had Calon Wen when staying in Wales as well as other natural or near natural foods such as Gower salt marsh lamb (£££ and strongly flavoured), laverbread and local wild sea bass !

  25. Christopher Palmer 20 October 2011 at 7:14 pm #

    DoctorM, Hi.

    Yours has been a helpful contribution to this debate. It’s only by transparent and objective discussion regarding differences of opinion that people can hope that differences of opinion may be resolved to the point where opinions may converge. Convergence alone does not indicate movement towards truth in matters but divergence indicates at least one view is wrong.

    At #20, above, you bring in discussion of casein and a distinction between types.

    I’m not medically trained but human co-evolution with diet interests me greatly for I think we owe a lot to trends and proficiencies associated with changes with our relationship with our food; these trends have left impressions upon us physiologically and sociologically.

    Furthermore, I think we continue to ‘evolve’ in the modern world – but I use the term with less emphasis upon the physiological and more emphasis upon the sociological and the economic. When I use the term ‘economic’ I consider the involvement of money and its ‘flow’ or circulation, but I consider with greater emphasis the activities that are associated with meeting needs and/or trading money.

    I think that the more highly capitalised are the enterprises that are involved in the provision and process of a societies or nations food and process derived comestibles the lesser are the nutritive qualities of the diet and the greater are the health issues. It’s an opinion, and one not yet fully featured nor yet fully researched, but if it can be taken forward it has potential to add faith to the principle and universality of cause and effect (considered de riguer in the physical sciences) to the social sciences. I carry in my head an ‘evolutionary model’ of modern human progress that has regard for agriculture, and capacity for agricultural surplus, plus regard for influence money can bring to bear lending a process of ‘selection’ to the evolution of human activities. selection that can be apparent, and at times detrimental, in medicine.

    If you plan to return to Wales and would like to meet, or if if you otherwise like to engage I am sure Dr B would put you in touch.

    This casein thing has recently blipped the outer limits of my radar. The Campbells discuss it The China Study. I haven’t arrived at a critical opinion of The China Study yet – and I’m unlikely to do so with so much attention as Denise Minger but almost half way through the work I am sceptical. While this casein issue may be valid the Campbells have great enthusiasm for it that invokes some suspicion in me, and the other aspect that makes me sceptical is that the Campbells appear to subscribe to the diet-heart hypothesis, while I find favour with the cholesterol sceptic view of the diet-heart hypothesis.

    Having bounced around some contextual concerns and interests can I ask can you direct a busy and obsessed distribution worker to sources that may be a good entry point to this casein issue?

    I am not just cholesterol sceptic but also I am sceptical of a certain kind of money. Cholesterol scepticism reinforces my money scepticism and money scepticism reinforces my cholesterol scepticism; a slightly ‘circular’ circumstance, I know.

    For an entry to money scepticism could I suggest Michael Rowbotham: The Grip of Death. I am only part way in, and I judge he has a grasp of his subject (destructive economics that stem from debt founded money), but despite the title I do not think he associates a type of money with unsatisfactory health outcomes or sub-optimal treatment regimes. I may have to obsess a while longer.

    Sue, at #21, let your own experience and observations be the basis of your opinion upon the views of John McDougal. I do not know John McDougal, but I consider certain people side with the agricultural expediency in growing plant crops as opposed to rearing meat (meat is eight times more consumptive of resources). They have a point, but the point is separate from nutritive issues, though often folks blur the distinction. Meat, and animal fat, has likely been hugely expedient in human physiological, intellectual, and sociological evolution. The vegetarian and low-fat lobby seems, in parts, to be possessed of an element of agenda that triumphs over real objectivity concerned with nutrition. The enterprising ape needs sufficient energy density in the diet. Grains can supply this level of energy density, but at the expense of complications (adiposity, obesity, T2 diabetes, auto-immune issues, etc.)

    I suspect much content is ‘good’ but I get a faint odour of agenda, be it wilful or unintentional, from content gracing The China Study.

  26. DoctorM 20 October 2011 at 8:45 pm #

    Kirsty. I do not have objection at all to natural animal fats. It is not just macronutrients (carbs, fat and protein) that are important but also micronutrients. If one gets a lot of calories from extracted fat whether from animal, vegetable, seeds, nuts or grains, one will be getting smaller relative amounts of calories from other much higher nutrient density foods including vegetables (especially), fruits and more nutritious parts of animal foods such as liver and other offal. I also do not think that one should get large amounts of fat from extracted olive oil (or milk ie butter) for similar reasons. I think we can best preserve a high level of macronutrients by eating a wide range of near natural wholefoods and this will also give a good balance balance between macronutrients. As regards our ancestral diet, I don’t think animals were (anywhere near) as high in fat as modern intensively farmed animals which get their huge amounts of fat from eating nutrient poor refined grains – corn and soy, meat from which (let’s face it) is almost all of what one gets in supermarkets – it is also likely to be high in unnatural fats – omega 6 – as well others – a million miles from natural. If one can feed one’s own pigs on a a high nutrient foraging diet than yes the pork will be excellent to eat – but better to eat all parts of the pig than just pick out the most fatty bits – if the fatty part is preserved as bacon and one can cure it oneself without sodium nitrite then excellent – but I wouldn’t make bacon a disproportionate part of the animal portion of the diet – our ancestors certainly couldn’t and wouldn’t – once they’d caught an animal (which would have been nowhere near as fatty as todays farmed animals) they would have eaten all parts of it. So I envy your ability to make your own near natural bacon.

  27. DoctorM 20 October 2011 at 9:20 pm #

    Christopher Palmer,
    As regards casein I suggest you google ‘A2 Milk’ -there are lot’s of odd bits on internet. It’s controversial of course (the commercialisation make one sceptical of course) and there are no absolutes – only judgements of relative risk. On balance though I think a2 casein is less risky than a1 casein and a1 casein is quite likely to be a cause of milk allergies.
    As regards the China Study, I think it is highly flawed. One of it’s messages – to eat natural whole foods – is absolutely right I think – but the message that all these foods should be plant is wrong and dangerous. Some time ago I posted a review on Amazon UK where I give my reasoning – it comes near the top of the first page of critical reviews – and could provide a forum for further discussion

  28. Chris 24 October 2011 at 11:33 am #

    Thanks DoctorM,

    for the guidance upon casein. The web is marvellously democratising even if some content is pay-to-view. But has not a discrete volume been written up on casein?
    Well put about the China Study, some good guidance within it, but perhaps not there for the right reasons.
    The ‘paleo’ dietary model may be a good model from which to fashion a modern eating plan, but the ‘paleo’ model, I feel, is open to subjectivity. I think the merit of comparing past and present diets can be very revealing, as can comparison of the modern diet with the diets of few remaining traditional peoples living a life of natural subsistence. I am little ambivalent towards the term itself while retaining high regard for the potential that analysis of trends and changes may hold.

    I am a little sceptical of one evident line of interpretation of the ‘paleo’ model that lean meat, plenty of it, is ‘healthy’. Quantity and context can have a bearing upon whether something is healthy – even water. Animal protein is, perhaps, to be preferred over plant proteins but we don’t have requirements for large quantities.
    Furthermore we have an evolutionary legacy of diets that pre-date the ‘paleo’. Far back, more ape-like ancestors ate an ‘ape-diet’ that was largely composed of plant foods. The diet may not have been high in fats but we cannot conclude automatically that it was low in fat. Why? Because plants can supply bulky foods that are not very dense in the macro-nutrients. In plant foods of low macro-nutrient density small quantities of fat by weight, can equate to significant energy supplied by fat as % of calories.
    [Check the nutrition box for watercress and do the calc; the effect upon perception is striking. Fats supply more than 30% of the cals, and of those I recall about 12% are saturated!]

    For some reason our ancestors (progenitors) had to leave the ape-diet behind. We may never know why, not with certainty, but climate change likely had a part. We did not become Palaeolithic hunter-gatherers overnight. There was a transitional period, and likely a long one. What did we eat in the transition? The wimp hypothesis has been proposed as a possible suggestion. We had no choice and lacked the abilities to do much else, but in adversity and hunger perhaps, found opportunities from scavenging. We exploited skeletal remains after predators had gorged upon kills. Using stones we broke open bones and extracted marrow, perhaps skulls were broke open too. In evolutionary time we got more adept at scaring off predators and reaped more food from the kill. It is documented that African tribesmen boldly approach a lion and brazenly steel a whole carcass to the utter bemusement of the lion. So the hypothesis may not without basis.

    Marrow fats are rich in fats that go on to form tissues of the brain, and fat rich marrow perhaps raised the energy density of the diet sufficiently to fuel an enlarging brain. I even speculate if the diet in the transitional phase could have turned ketogenic and remained so for tens, if not hundreds of thousands of years, and then I wonder if the ketogenic diet sharpened the mind ever so slightly, and added reinforcement to the virtuous circle of enlarging brain, improving social interactions, and, possibly, emerging trends to cooperative behavioural strategies, and a growing intellect and ‘efficiency’ intrinsic to the brain. Size alone doesn’t explain everything.

    I am certain three phases of the evolution of the human diet have imprinted legacies within our physiological requirements, not just one from the Paleolithic. What’s hard to asses is what adaptations have been promoted, preserved, or denuded, during several million years of co-evolution with diet. Analysis is conjectural and without certainty. The clearest things, we can be sure of, are those changes that equate to recent introductions during the agricultural, the modern agricultural, and process dependent ages. We seem ill-suited, beyond doubt, to certain of these.

  29. DoctorM 24 October 2011 at 10:43 pm #

    Chris,
    Thanks for comments. It’s just not clear how far (1000 , 10000, 40000 ,100000 years ?) we need to go back to identify the ‘best’ modern day human diet and even more difficult to reproduce it today. I think one just needs to make one’s own asessment of risk of different food types. Processed much more risky than natural, GM a total disaster, grains/milk a bit more risky than traditional paleo foods etc. I am not sure about animal vs plant protein so hedge my bets and have about half and half without overdosing on protein. Fats and carbs are then those of the very varied wholefoods I eat – and I certainly do not overeat. This is just what I do but I think that quite a wide range of wholefood diets are healthy from near vegan to quite meaty. We all make our judgements and take our chances. All the best.

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