- Email: [email protected]
An end to meat mythology
Reports/Viewpoint
Implications
for planning
Food plays a major role inexpenditure, particularly among the poor. Expenditure elasticities for focd tend to hold at relatively high levels, above 6.6, even among developed nations. Closer examination indicates that this high elasticity may be attributed in part to increased quantity demand, but even more to the demand for more expensive
varieties. This trend is observed in many countries and merits consideration by planners from a number of perspectives. If the PTD component is likely to increase. then planners should analyse the implications on the one hand of possible future income generation and on the other hand the possibilities for redistributing towards the lower income groups by quality oriented policies.
Viewpoint The editors arguments
of Food Policy and
welcome
counter-arguments
contributions on important
to this section and
topical
presenting
developments
and issues.
An end to meat mythology Colin Tudge No-one who has read the statistics can fail to see that the greatest single contribution the west could make towards increasing the total food available in the world would be for us all to move a little up the food chain. Vegetarianism is unnecessary, but for the west to restore livestock to its more ecological role as scavenger and sweeper, and to reintroduce the peasant cuisines in which meat garnished vegetable instead of the other way around, could release volumes of grain almost as great as the Third World now consumes in toto. But there, except for the small gesture by the Norwegians recently, that line of thinking tends to end. It comes up mutually supportive against three arguments, each of impeccable pedigree, which between them suggest that for westerners voluntarily to abandon their meatbased food habits is inconceivable, and that to plead for such a shift is simply to waste valuable debating time. Why
eat meat?
The first of these arguments is that meat production is crucial to the west’s agricultural economy - which means, in effect, the economy as a whole. The second - the biological argument - is that human beings are naturally inclined to eat meat, when available, and that for them voluntarily to eat less would Colin Tudge Medicine.
82
is features
editor
of World
therefore be to fly in the face of nature; that it would involve a degree of asceticism and self-sacrifice far outside normal acceptance. And the third political - argument is that since people do have an overweening desire for meat, then democratically elected governments would betray their function, indeed find it impossible, to curb its production unless forced to do so by outside economic pressures. In short, meat-orientated agriculture and diet are inevitable in rich democracies and to rail against such inescapable facts is merely diversionary. Yet this three-point argument, so universally if sometimes unconsciously accepted, is almost entirely spurious. At least the economic argument is true meat does play a key role in balancing the farming books. But the biology is of uncritical, or rather the same unquestioned variety that in the late nineteenth century prompted leading anthropologists to demonstrate that white men were biologically superior to black, or which a generation previously had shown that Britain’s ferociously heirarchical society was merely an analogue of Nature’s ‘survival of the fittest’. It is the biology of convenience or of prevailing politics or commerce; a crude speculative attempt to explain away the status quo in scientific terms. What then is the ‘natural’ diet of human beings? And how, if they are not innately and emphatically carnivorous, can one explain the almost one-to-one relationship between meat-eating and
afRuence, which so alluringly suggests that it is only the accident of poverty that suppresses man’s expression of his deep atavistic instincts?
A ‘natural’ diet First question first - and an extremely difficult one, since the idea of a ‘natural’ diet has many separate, and to some extent conflicting, connotations. For me a ‘natural’ diet is one to which human beings are physiologically adapted to thrive upon. This means a healthy diet, ‘health’ implies a sound since relationship with environment. So what keeps human beings healthy? There is no simple answer to this, but a few obvious guidelines. First, that they need to avoid toxins. Second that they erzough ~ calories, protein, need essential fats, vitamins and minerals and that deficiencies, sooner or later, produce clinical signs of disease. Here, in the past decade, there have been two major changes of concept: the first promoted by scientists like P.V. Sukhatme, Donald S. McLaren, and others, suggesting that humans need far less protein than was hitherto supposed _ indeed, that a diet containing only about 5% of its calories in the form of high grade protein is adequate; and the emphasised particularly by second, Michael Crawford, that the essential, polyunsaturated fats are needed in greater amounts and variety than was previously recommended, because the body cannot interconvert the different types (and so use a surplus of one to make good deficiencies of others) quite so freely as the biochemists were apt to suppose. And that is as far as this line of thought can take us, for the fact is that human beings, in common with rats, dogs, and cockroaches, can survive on an extraordinary variety of diets, and can adapt to minor deficiencies for decades at a time, even though failing to realise their full physical or intellectual potential.
Optimum
requirements
More to the point, in trying to define a healthy diet we should seek to discover not merely the minimum, but the optimum requirements. This would be simple if we could define exactly the size and shape that human beings should be, in the same way as the farmer
FOOD
POLICY
February
1977
Viewpoint prescribes the ideal pig or cow. But does the modern American man, about six feet tall and weighing around lOOkg, have a more desirable physique than the English Tudor aristocrat. who rarely grew above five feet six? Is the high-fat, high-calorie. high-protein diet of the USA desirable because it produces big people? If the answer is ‘no’, or ‘not then what criteria are necessarily’, relevant in judging the quality of diet, clinical toxicity and nnce acute deficiency have been avoided? Longevity is surely a criterion, and here the modern western diet seems to fall short. The biggest single killer by far in the west is coronary heart disease, striking hard in the fifth and sixth decades. and if the evidence is incomplete, common sense, at least, suggests that diet is strongly implicated. So. to narrow the question, what components of the western diet produce the apparently food-related conditions that are unquestionably associated with alfluence - of which coronary heart disease is the chief, but also including diabetes, gallstones, and gut disorders ranging from constipation to cancer of the colon?
Three theories Here there are three main categories of not theory. which are mutually exclusive, even though they do tend to produce contradictory medical advice. The first - particularly relevant to excessive heart disease - implicates intake of saturated fat, which means the adipose, as opposed to structural, fat of animals. This tends to raise blood cholesterol levels, and cholesterol is undoubtedly involved in forming the atheromata which clog the arteries of western people. The second, advocated particularly by Professor John Yudkin, is that excessive intake of refined carbohydrate _ in particular sucrose - undermines health, both by providing excess calories without any accompanying essential nutrients, and by producing direct toxic effects. And the third - in part a corollary of Yudkin’s idea, and produced initially by T.L. Cleave - is that lack of dietary fibre predisposes people not only to coronary heart disease. but to all the other dietary evils of aflluence as well.
FOOD
POLICY
February
1977
Again, the effects are said to be both direct and indirect: fibre does influence gut function, including liver metabolism, and its lack may have pathological effects: and the presence of fibre in unrefined carbohydrate food prevents excessive intake of the excessively calorific. and putatively toxic, sugar. These arguments represent the best to date. to define the attempts, shortcomings of a western diet that is not obviously deficient, but appears to injure by excess. Disparate as they are, these arguments have one strong common thread. They all suppose that the metabolism of human beings is not adapted to what westerners now eat. Which leaves us with the question we began with: what are humans adapted to eat? And suggests that we must pursue yet another line of enquiry. Let us make the common sense assumption that human beings are adapted to eat the food that was available before they acquired the technique and power to be as choosy as they are now; in other words, to the diet available in the 30 million years that elapsed between the primates’ diversion from their insectivore progenitors, and man’s, chief primates’, first the incursions into agriculture. For it is in that period that evolution shaped the metabolisms that we have inherited, and that we now rather unsuccessfully endeavour to keep intact. In truth, the diet of primitive men would not, even if we could exactly define it. necessarily tell us what we should eat today: after all, our distant ancestors lived very different lives from us; and probably they rarely lived far beyond reproductive age. A diet that merely kept them alive for 20 years would not necessarily keep us overtly healthy for 70 years or more. But it is still sensible to ask - as all the modern nutritional theorists have asked - what kind of a physiological beast is the human being? And it is still at least reasonable to ask what men were forced to eat when they were less protected from the environmental rigours than they are today.
Theoretical wrong directions And here, I suggest, some of the nutritional theorists have gone badly wrong. The widely accepted rubric -
emphasised in particular by Professor Yudkin - goes roughly as follows. The insectivores from which primates descended ate (presumably) insects, as their modern direct descendents, from tree-shrews to moles. still do. The continued supreme adaptation to the forests, which shaped early primate evolution, led them to a vegetarian diet. Then, about three million years ago, as Savannah encroached on forest, a group of ape-like creatures began life on the ground, and there. with vegetation scarce. became largely carnivorous. Then 15 to 10 000 years ago came what Yudkin calls the neolithic dietary revolution, as newly agricultural man had again to rely on plant foods. Finally came the industrial dietary revolution, still underway, as men increasingly began to refine the carbohydrate of their plant-based diet. This evolutionary thesis has a lot going for it. It accords with much of the palaeontological evidence. And it seems to explain many modern dietary phenomena. After all. man’s early carnivorous leanings help explain his intellectual and manual breakaway from the other primates, since hunting, particularly for a small beast without benefit of tooth or claw, requires wit and dexterity and would encourage development of fire, both to break down tough sinews and to break the life cycles of endo-parasites. It also, according to Yudkin, explains modern man’s dietary ills, since his meat-orientated metabolism simply is not equipped to cope with all that post-agricultural carbohydrate. And it explains why societies. as they grow richer, eat more meat: they are simply expressing their atavistic instincts. And that, supposedly, is why it would be so difficult for rich human beings to reverse their carnivorous leanings.
False premises But I suggest this key nutritional thesis is based on false premises - a bad start for any hypothesis - and is far too elaborate. For a start, primates are now known to be nothing like so herbivorous as was once supposed: the officiously vegetarian types, such as the orang, are atypical specialists. Monkeys, for the most part, are omnivorous: and baboons and chimpanzees are now
a3
Viewpoinf known not only to eat meat, but actually to hunt. So the allegedly radical dietary shift that the first men were supposed to have made when they first left the forest - a shift so romantically elaborated by Robert Ardrey, in African Genesis - was probably no more than a shift of emphasis. The manapes were already meat-eaters. And did they become out-and-out weapons, carnivores? They had certainly. But how successfully would they have competed with the specialist carnivores, the cats, foxes, hunting dogs and hyaenas, or tracked the animals adapted to avoid those predators? Scavenging would have offered no easy route to carnivorousness, as the van Lawick Goodalls have pointed out; here, the competition from lion, leopard, hyaena and dog is at least as fierce as.in the hunt. Modern baboons and chimpanzees show that apparently illadapted primates can hunt; but neither is more than an opportunist. And did the birth of agriculture really produce such a revolution in diet? After all, remains of domestic and semidomestic livestock can be traced back deep into the neolithic. And Cain’s brother, Abel, was a favoured pastoralist. So instead of invoking ‘dietary revolution’, and seeking to explain our present dietary predelictions in terms of atavism, of ancient urges carved into our psyche, would it not be more profitable to accept that people are omnivores, descended from omnivores, and ask what this implies?
Omnivorous people First, at the crude physiological level, it neatly reconciles many of the current nutritional theories. Why should we need great amounts of high class protein, if we are directly descended from beasts who were only opportunist hunters? Why should we not be able to survive on the protein present in seeds, which in practice, today, means grains and beans? If high levels of saturated fat, or low levels of polyunsaturated fat, are harmful, could this not be because our primitive diet contained only small amounts of meat - and that, as Crawford has pointed out, both extremely lean and rich in’the structural
fats? And does the modern epidemiological evidence really suggest that we are ill-adapted to carbohydrate, as Yudkin tends to imply, or merely that we need our carbohydrate diluted, as in nature, by fibrous plant-cell walls? And given that coronary heart disease, for example. is ‘multifactorial’ in origin (as the physicians constantly emphasise) should we really expect to be able to incriminate any one factor (fat or carbohydrate) exclusively, or should we be looking for a mix? In short, there is hardly any aspect of the more sensible modern nutritional theories that cannot be related simply to the idea that we were pressured by nature, from the beginning, to live on a rough, mixed, ‘wild’ diet. Second, more subtly, what of the psychology of omnivores? The conventional text-books are apt to underplay omnivorousness. Herbivores, they tell us, are supremely adapted to a coarse, bulky diet, with teeth moulded like querns to smash the fibre, and huge guts to accommodate it. Carnivoies have scissor-like jaws, and short guts producing coruscating proteolytic enzymes. Omnivores (the rubric goes) are mere mediocrities, doing everything after a fashion, but nothing really well. But this simplistic analysis overlooks the fact that omnivorousness is the most demanding habit of all. The specialist feeder needs only a relatively simple psychology: an instinctive predeliction for one class of food, and an equally ~unthinking’ aversion to another. But all components of the environment are potentially ‘food’ to the omnivore. He must, whether he is a rat, a pigeon, or a human being, investigate. But such experimentation is hazardous: the wider the quest, the greater the chance of being poisoned. In theory, the need to experiment must be tempered by conservatism; and in practice, this balance of opposites is precisely what is observed. Thus rats are difficult to poison because they are suspicious of bait, no matter how esculent. More generally, wild populations of animals tend to select only a proportion of the potential foods available to them: zoo collectors have to wean them away from the diets they prefer in the wild, to those available in captivity. ‘Primitive’ populations of humans, despite an often encyclopaedic
knowledge of the local flora and fauna, characteristically select only a small proportion of what is available different tribes, as with different animal of the same populations species, selecting different catalogues. The experimentalism explains why some populations go to such inordinate lengths to obtain apparently puzzling items of food. like the Chinese with their birds’ nests and sharks’ fins: and the conservatism, why people have at times preferred to starve. rather than accept wheat instead of rice, say, or even different varieties of rice. The new items are simply ‘non-food’. ‘Taboo’ is merely this conservatism given literary form.
Choosing taboos But how does each human group arrive at its catalogue of favoured items, and its taboos? The process is certainly erratic: some groups, like the French with their horsemeat and snails, or the Lancastrians with their black puddings, extol foods that provoke nausea in others. Yet the process does have some Human beings, like other order. animals, do adopt general guidelines easily recogniseable Ravours that are known from experience not to produce immediately unpleasant effects. Thus we arrive at a simple model of omnivorousness, requiring nothing that evolution would not have demanded, or that does not accord with what is immediately observable. It supposes that the infant’s palate is more or less a tabula rasa; some children in Britain may grow up with a loathing for carrots, and some may be allergic to cheese, but in general, as good ommvores, they adapt to what is around. Rut they tend to seize, with their conservative experimentalism, on sharp flavours either associated with immediate uplifting effects, or, at least, not unpleasant effects. Such a genera1 hypothesis, all that the known facts explains, when extrapolated, justify. why coffee, tea, and chocolate have in their more limited compass made as great an impact on western food habits as meat has; but if you invent a special hypothesis to explain our present predeliction for meat, you must either invent separate hypotheses for all other innovations or else - which is stretching
FOOD
POLICY
February
1977
VieElpointlLetter imagination a little far - suppose that our primitive ancestors drank tea and smoked, and that these fashions are too, are atavistic. So we can fit present meat-eating into a general theory of omnivorousness. We can add to that the obvious fact that meat-eating has always had social kudos, because meat is after all, pleasant (as is sherbert, or Scotch) and what expensive. For intrinsically evidence is there, once you remove this connotation, of such an social overweening desire for the flesh that we need to provide it with a special multihistorical theory? After all, the Chinese Mandarins, who hardly needed to prove this social status, rejected the flesh of ducks in favour of the skin: no great Brillat-Savarin, lust there. blood French even among outstanding gourmets, wrote of the splendours of hare and of saddles of mutton; no great
emphasis there on the boring fillets of beef that now symbolise our well-being. Take away meat’s social cachet, and it ceases to enjoy a special place in diet; it becomes merely one delightful item among many.
Not nature but economics So to explain the great rise in meateating in the west, we have, according to this general idea of omnivorousness merely to explain why so much meat has become available. And that is obvious - the first of the three points raised in my second paragraph: that its production has been necessary, to help lay the spectre of over-production. The meat has not exactly been forced from the farmers by clamorous demand: in my lifetime at least it has been as vigorously promoted as any other commercial item. and as late as October
to the editor
1975 we were being urged to ‘buy a bigger piece’ of English beef. there are obvious To conclude, economic objections to the suggestion that we should curb our agricultural profligacy by veering away from livestock. But those objections do not deserve the support of biologists; they should not be seen as ‘natural’, and therefore in some sense ineluctable. It would certainly be possible by the right kind of propaganda - indeed by ‘education’, since we are talking about broadening awareness, and not simply of selling a convenient rubric - to persuade people to pursue a more varied, more peasant-like, and certainly less meat-orientated diet than they now have: of the kind, indeed, that people have eaten for three million years. For governments to duck this responsibility is cowardly; to use science as a reason for not doing the obvious, is dishonest.
Letter to the editor Agriculture in the EEC - taking stock Another view Sir, Messrs MacKerron and Rush have presented an interesting assessment of a stocktaking.’ My stocktaking at the third remove will attempt to avoid rhetoric and remain factual, even if all the arguments cannot be statistically documented. As usual in this kind of exercise, the emphasis will be on the differences of opinion rather than on points of agreement. Much of my disagreement with the authors stems from the fact that they artificially separated the Common Agricultural Policy (CAP) of the European Economic Community (EEC) from the national agricultural policies of the member countries. They state: ‘to make the task manageable, we have confined ourselves to examining common policies, and do not explicitly consider national policy at all’ (p 287). Rejection of this narrowing down of the analysis does not imply that I feel I have adequate knowledge about nine national policies and the CAP or the insight needed to clarify their causes and effects. It just means that I think that national policies and the CAP are in fact so closely related that they must be looked at jointly.
FOOD
POLICY
February 1977
My discussion will follow the pattern of that in the paper under review, ie firstly comment on the performance of the CAP and the stocktaking document under eight headings (‘objectives’) and then some more general remarks and conclusions.
Meeting CAP objectives The discussion concerning the free movement of goods rightly stresses the importance of the monetary compensatory amounts (MCAs). Both the Stocktaking and the authors’ discussion show that they are a step backwards. Obviously the real solution lies in greater unity, a closer coordination of economic and monetary policies. One cannot expect the CAP to work smoothly without these improvements. With regard to increasing productivitv, MacKerron and Rush state: ‘The CAP has had virtually no direct, and probably little indirect, effect on productivity’ (p 289). It is true that research, teaching and advisory services are essentially national and not common responsibilities (and the fact
that their levels of effectiveness are so different from one member country to another is a very real distortion of competition). It does appear however, both from micro-economic studies and from various more global analysis, that the price stability and price increases gained from the CAP have very strong effects on the investment decisions of farmers. Price policies have accelerated the adoption of new technology and increased the rate of capital formation. This has an evident influence on productivity (this reasoning is explicitly formulated in the Stocktaking). MacKerron and Rush recognise that labour productivity has ‘increased extremely rapidly’ (p 290). They attribute this to national structural policies rather than to the CAP. Measuring the consequences of policies raises structural several methodological difficulties exceeding the scdpe of this review. My hypothesis is stabilisation that price and price supports - obtained through national polices and later from the CAP - have created a significant incentive to structural changes, and have been more ’ Gordon MacKerron and Howard J. Rush, ‘Aqriculture in the EEC - taking stock’, F&d Policy, Vol 1 No 4, pp 2861 300.
85
Implications
for planning
Food plays a major role inexpenditure, particularly among the poor. Expenditure elasticities for focd tend to hold at relatively high levels, above 6.6, even among developed nations. Closer examination indicates that this high elasticity may be attributed in part to increased quantity demand, but even more to the demand for more expensive
varieties. This trend is observed in many countries and merits consideration by planners from a number of perspectives. If the PTD component is likely to increase. then planners should analyse the implications on the one hand of possible future income generation and on the other hand the possibilities for redistributing towards the lower income groups by quality oriented policies.
Viewpoint The editors arguments
of Food Policy and
welcome
counter-arguments
contributions on important
to this section and
topical
presenting
developments
and issues.
An end to meat mythology Colin Tudge No-one who has read the statistics can fail to see that the greatest single contribution the west could make towards increasing the total food available in the world would be for us all to move a little up the food chain. Vegetarianism is unnecessary, but for the west to restore livestock to its more ecological role as scavenger and sweeper, and to reintroduce the peasant cuisines in which meat garnished vegetable instead of the other way around, could release volumes of grain almost as great as the Third World now consumes in toto. But there, except for the small gesture by the Norwegians recently, that line of thinking tends to end. It comes up mutually supportive against three arguments, each of impeccable pedigree, which between them suggest that for westerners voluntarily to abandon their meatbased food habits is inconceivable, and that to plead for such a shift is simply to waste valuable debating time. Why
eat meat?
The first of these arguments is that meat production is crucial to the west’s agricultural economy - which means, in effect, the economy as a whole. The second - the biological argument - is that human beings are naturally inclined to eat meat, when available, and that for them voluntarily to eat less would Colin Tudge Medicine.
82
is features
editor
of World
therefore be to fly in the face of nature; that it would involve a degree of asceticism and self-sacrifice far outside normal acceptance. And the third political - argument is that since people do have an overweening desire for meat, then democratically elected governments would betray their function, indeed find it impossible, to curb its production unless forced to do so by outside economic pressures. In short, meat-orientated agriculture and diet are inevitable in rich democracies and to rail against such inescapable facts is merely diversionary. Yet this three-point argument, so universally if sometimes unconsciously accepted, is almost entirely spurious. At least the economic argument is true meat does play a key role in balancing the farming books. But the biology is of uncritical, or rather the same unquestioned variety that in the late nineteenth century prompted leading anthropologists to demonstrate that white men were biologically superior to black, or which a generation previously had shown that Britain’s ferociously heirarchical society was merely an analogue of Nature’s ‘survival of the fittest’. It is the biology of convenience or of prevailing politics or commerce; a crude speculative attempt to explain away the status quo in scientific terms. What then is the ‘natural’ diet of human beings? And how, if they are not innately and emphatically carnivorous, can one explain the almost one-to-one relationship between meat-eating and
afRuence, which so alluringly suggests that it is only the accident of poverty that suppresses man’s expression of his deep atavistic instincts?
A ‘natural’ diet First question first - and an extremely difficult one, since the idea of a ‘natural’ diet has many separate, and to some extent conflicting, connotations. For me a ‘natural’ diet is one to which human beings are physiologically adapted to thrive upon. This means a healthy diet, ‘health’ implies a sound since relationship with environment. So what keeps human beings healthy? There is no simple answer to this, but a few obvious guidelines. First, that they need to avoid toxins. Second that they erzough ~ calories, protein, need essential fats, vitamins and minerals and that deficiencies, sooner or later, produce clinical signs of disease. Here, in the past decade, there have been two major changes of concept: the first promoted by scientists like P.V. Sukhatme, Donald S. McLaren, and others, suggesting that humans need far less protein than was hitherto supposed _ indeed, that a diet containing only about 5% of its calories in the form of high grade protein is adequate; and the emphasised particularly by second, Michael Crawford, that the essential, polyunsaturated fats are needed in greater amounts and variety than was previously recommended, because the body cannot interconvert the different types (and so use a surplus of one to make good deficiencies of others) quite so freely as the biochemists were apt to suppose. And that is as far as this line of thought can take us, for the fact is that human beings, in common with rats, dogs, and cockroaches, can survive on an extraordinary variety of diets, and can adapt to minor deficiencies for decades at a time, even though failing to realise their full physical or intellectual potential.
Optimum
requirements
More to the point, in trying to define a healthy diet we should seek to discover not merely the minimum, but the optimum requirements. This would be simple if we could define exactly the size and shape that human beings should be, in the same way as the farmer
FOOD
POLICY
February
1977
Viewpoint prescribes the ideal pig or cow. But does the modern American man, about six feet tall and weighing around lOOkg, have a more desirable physique than the English Tudor aristocrat. who rarely grew above five feet six? Is the high-fat, high-calorie. high-protein diet of the USA desirable because it produces big people? If the answer is ‘no’, or ‘not then what criteria are necessarily’, relevant in judging the quality of diet, clinical toxicity and nnce acute deficiency have been avoided? Longevity is surely a criterion, and here the modern western diet seems to fall short. The biggest single killer by far in the west is coronary heart disease, striking hard in the fifth and sixth decades. and if the evidence is incomplete, common sense, at least, suggests that diet is strongly implicated. So. to narrow the question, what components of the western diet produce the apparently food-related conditions that are unquestionably associated with alfluence - of which coronary heart disease is the chief, but also including diabetes, gallstones, and gut disorders ranging from constipation to cancer of the colon?
Three theories Here there are three main categories of not theory. which are mutually exclusive, even though they do tend to produce contradictory medical advice. The first - particularly relevant to excessive heart disease - implicates intake of saturated fat, which means the adipose, as opposed to structural, fat of animals. This tends to raise blood cholesterol levels, and cholesterol is undoubtedly involved in forming the atheromata which clog the arteries of western people. The second, advocated particularly by Professor John Yudkin, is that excessive intake of refined carbohydrate _ in particular sucrose - undermines health, both by providing excess calories without any accompanying essential nutrients, and by producing direct toxic effects. And the third - in part a corollary of Yudkin’s idea, and produced initially by T.L. Cleave - is that lack of dietary fibre predisposes people not only to coronary heart disease. but to all the other dietary evils of aflluence as well.
FOOD
POLICY
February
1977
Again, the effects are said to be both direct and indirect: fibre does influence gut function, including liver metabolism, and its lack may have pathological effects: and the presence of fibre in unrefined carbohydrate food prevents excessive intake of the excessively calorific. and putatively toxic, sugar. These arguments represent the best to date. to define the attempts, shortcomings of a western diet that is not obviously deficient, but appears to injure by excess. Disparate as they are, these arguments have one strong common thread. They all suppose that the metabolism of human beings is not adapted to what westerners now eat. Which leaves us with the question we began with: what are humans adapted to eat? And suggests that we must pursue yet another line of enquiry. Let us make the common sense assumption that human beings are adapted to eat the food that was available before they acquired the technique and power to be as choosy as they are now; in other words, to the diet available in the 30 million years that elapsed between the primates’ diversion from their insectivore progenitors, and man’s, chief primates’, first the incursions into agriculture. For it is in that period that evolution shaped the metabolisms that we have inherited, and that we now rather unsuccessfully endeavour to keep intact. In truth, the diet of primitive men would not, even if we could exactly define it. necessarily tell us what we should eat today: after all, our distant ancestors lived very different lives from us; and probably they rarely lived far beyond reproductive age. A diet that merely kept them alive for 20 years would not necessarily keep us overtly healthy for 70 years or more. But it is still sensible to ask - as all the modern nutritional theorists have asked - what kind of a physiological beast is the human being? And it is still at least reasonable to ask what men were forced to eat when they were less protected from the environmental rigours than they are today.
Theoretical wrong directions And here, I suggest, some of the nutritional theorists have gone badly wrong. The widely accepted rubric -
emphasised in particular by Professor Yudkin - goes roughly as follows. The insectivores from which primates descended ate (presumably) insects, as their modern direct descendents, from tree-shrews to moles. still do. The continued supreme adaptation to the forests, which shaped early primate evolution, led them to a vegetarian diet. Then, about three million years ago, as Savannah encroached on forest, a group of ape-like creatures began life on the ground, and there. with vegetation scarce. became largely carnivorous. Then 15 to 10 000 years ago came what Yudkin calls the neolithic dietary revolution, as newly agricultural man had again to rely on plant foods. Finally came the industrial dietary revolution, still underway, as men increasingly began to refine the carbohydrate of their plant-based diet. This evolutionary thesis has a lot going for it. It accords with much of the palaeontological evidence. And it seems to explain many modern dietary phenomena. After all. man’s early carnivorous leanings help explain his intellectual and manual breakaway from the other primates, since hunting, particularly for a small beast without benefit of tooth or claw, requires wit and dexterity and would encourage development of fire, both to break down tough sinews and to break the life cycles of endo-parasites. It also, according to Yudkin, explains modern man’s dietary ills, since his meat-orientated metabolism simply is not equipped to cope with all that post-agricultural carbohydrate. And it explains why societies. as they grow richer, eat more meat: they are simply expressing their atavistic instincts. And that, supposedly, is why it would be so difficult for rich human beings to reverse their carnivorous leanings.
False premises But I suggest this key nutritional thesis is based on false premises - a bad start for any hypothesis - and is far too elaborate. For a start, primates are now known to be nothing like so herbivorous as was once supposed: the officiously vegetarian types, such as the orang, are atypical specialists. Monkeys, for the most part, are omnivorous: and baboons and chimpanzees are now
a3
Viewpoinf known not only to eat meat, but actually to hunt. So the allegedly radical dietary shift that the first men were supposed to have made when they first left the forest - a shift so romantically elaborated by Robert Ardrey, in African Genesis - was probably no more than a shift of emphasis. The manapes were already meat-eaters. And did they become out-and-out weapons, carnivores? They had certainly. But how successfully would they have competed with the specialist carnivores, the cats, foxes, hunting dogs and hyaenas, or tracked the animals adapted to avoid those predators? Scavenging would have offered no easy route to carnivorousness, as the van Lawick Goodalls have pointed out; here, the competition from lion, leopard, hyaena and dog is at least as fierce as.in the hunt. Modern baboons and chimpanzees show that apparently illadapted primates can hunt; but neither is more than an opportunist. And did the birth of agriculture really produce such a revolution in diet? After all, remains of domestic and semidomestic livestock can be traced back deep into the neolithic. And Cain’s brother, Abel, was a favoured pastoralist. So instead of invoking ‘dietary revolution’, and seeking to explain our present dietary predelictions in terms of atavism, of ancient urges carved into our psyche, would it not be more profitable to accept that people are omnivores, descended from omnivores, and ask what this implies?
Omnivorous people First, at the crude physiological level, it neatly reconciles many of the current nutritional theories. Why should we need great amounts of high class protein, if we are directly descended from beasts who were only opportunist hunters? Why should we not be able to survive on the protein present in seeds, which in practice, today, means grains and beans? If high levels of saturated fat, or low levels of polyunsaturated fat, are harmful, could this not be because our primitive diet contained only small amounts of meat - and that, as Crawford has pointed out, both extremely lean and rich in’the structural
fats? And does the modern epidemiological evidence really suggest that we are ill-adapted to carbohydrate, as Yudkin tends to imply, or merely that we need our carbohydrate diluted, as in nature, by fibrous plant-cell walls? And given that coronary heart disease, for example. is ‘multifactorial’ in origin (as the physicians constantly emphasise) should we really expect to be able to incriminate any one factor (fat or carbohydrate) exclusively, or should we be looking for a mix? In short, there is hardly any aspect of the more sensible modern nutritional theories that cannot be related simply to the idea that we were pressured by nature, from the beginning, to live on a rough, mixed, ‘wild’ diet. Second, more subtly, what of the psychology of omnivores? The conventional text-books are apt to underplay omnivorousness. Herbivores, they tell us, are supremely adapted to a coarse, bulky diet, with teeth moulded like querns to smash the fibre, and huge guts to accommodate it. Carnivoies have scissor-like jaws, and short guts producing coruscating proteolytic enzymes. Omnivores (the rubric goes) are mere mediocrities, doing everything after a fashion, but nothing really well. But this simplistic analysis overlooks the fact that omnivorousness is the most demanding habit of all. The specialist feeder needs only a relatively simple psychology: an instinctive predeliction for one class of food, and an equally ~unthinking’ aversion to another. But all components of the environment are potentially ‘food’ to the omnivore. He must, whether he is a rat, a pigeon, or a human being, investigate. But such experimentation is hazardous: the wider the quest, the greater the chance of being poisoned. In theory, the need to experiment must be tempered by conservatism; and in practice, this balance of opposites is precisely what is observed. Thus rats are difficult to poison because they are suspicious of bait, no matter how esculent. More generally, wild populations of animals tend to select only a proportion of the potential foods available to them: zoo collectors have to wean them away from the diets they prefer in the wild, to those available in captivity. ‘Primitive’ populations of humans, despite an often encyclopaedic
knowledge of the local flora and fauna, characteristically select only a small proportion of what is available different tribes, as with different animal of the same populations species, selecting different catalogues. The experimentalism explains why some populations go to such inordinate lengths to obtain apparently puzzling items of food. like the Chinese with their birds’ nests and sharks’ fins: and the conservatism, why people have at times preferred to starve. rather than accept wheat instead of rice, say, or even different varieties of rice. The new items are simply ‘non-food’. ‘Taboo’ is merely this conservatism given literary form.
Choosing taboos But how does each human group arrive at its catalogue of favoured items, and its taboos? The process is certainly erratic: some groups, like the French with their horsemeat and snails, or the Lancastrians with their black puddings, extol foods that provoke nausea in others. Yet the process does have some Human beings, like other order. animals, do adopt general guidelines easily recogniseable Ravours that are known from experience not to produce immediately unpleasant effects. Thus we arrive at a simple model of omnivorousness, requiring nothing that evolution would not have demanded, or that does not accord with what is immediately observable. It supposes that the infant’s palate is more or less a tabula rasa; some children in Britain may grow up with a loathing for carrots, and some may be allergic to cheese, but in general, as good ommvores, they adapt to what is around. Rut they tend to seize, with their conservative experimentalism, on sharp flavours either associated with immediate uplifting effects, or, at least, not unpleasant effects. Such a genera1 hypothesis, all that the known facts explains, when extrapolated, justify. why coffee, tea, and chocolate have in their more limited compass made as great an impact on western food habits as meat has; but if you invent a special hypothesis to explain our present predeliction for meat, you must either invent separate hypotheses for all other innovations or else - which is stretching
FOOD
POLICY
February
1977
VieElpointlLetter imagination a little far - suppose that our primitive ancestors drank tea and smoked, and that these fashions are too, are atavistic. So we can fit present meat-eating into a general theory of omnivorousness. We can add to that the obvious fact that meat-eating has always had social kudos, because meat is after all, pleasant (as is sherbert, or Scotch) and what expensive. For intrinsically evidence is there, once you remove this connotation, of such an social overweening desire for the flesh that we need to provide it with a special multihistorical theory? After all, the Chinese Mandarins, who hardly needed to prove this social status, rejected the flesh of ducks in favour of the skin: no great Brillat-Savarin, lust there. blood French even among outstanding gourmets, wrote of the splendours of hare and of saddles of mutton; no great
emphasis there on the boring fillets of beef that now symbolise our well-being. Take away meat’s social cachet, and it ceases to enjoy a special place in diet; it becomes merely one delightful item among many.
Not nature but economics So to explain the great rise in meateating in the west, we have, according to this general idea of omnivorousness merely to explain why so much meat has become available. And that is obvious - the first of the three points raised in my second paragraph: that its production has been necessary, to help lay the spectre of over-production. The meat has not exactly been forced from the farmers by clamorous demand: in my lifetime at least it has been as vigorously promoted as any other commercial item. and as late as October
to the editor
1975 we were being urged to ‘buy a bigger piece’ of English beef. there are obvious To conclude, economic objections to the suggestion that we should curb our agricultural profligacy by veering away from livestock. But those objections do not deserve the support of biologists; they should not be seen as ‘natural’, and therefore in some sense ineluctable. It would certainly be possible by the right kind of propaganda - indeed by ‘education’, since we are talking about broadening awareness, and not simply of selling a convenient rubric - to persuade people to pursue a more varied, more peasant-like, and certainly less meat-orientated diet than they now have: of the kind, indeed, that people have eaten for three million years. For governments to duck this responsibility is cowardly; to use science as a reason for not doing the obvious, is dishonest.
Letter to the editor Agriculture in the EEC - taking stock Another view Sir, Messrs MacKerron and Rush have presented an interesting assessment of a stocktaking.’ My stocktaking at the third remove will attempt to avoid rhetoric and remain factual, even if all the arguments cannot be statistically documented. As usual in this kind of exercise, the emphasis will be on the differences of opinion rather than on points of agreement. Much of my disagreement with the authors stems from the fact that they artificially separated the Common Agricultural Policy (CAP) of the European Economic Community (EEC) from the national agricultural policies of the member countries. They state: ‘to make the task manageable, we have confined ourselves to examining common policies, and do not explicitly consider national policy at all’ (p 287). Rejection of this narrowing down of the analysis does not imply that I feel I have adequate knowledge about nine national policies and the CAP or the insight needed to clarify their causes and effects. It just means that I think that national policies and the CAP are in fact so closely related that they must be looked at jointly.
FOOD
POLICY
February 1977
My discussion will follow the pattern of that in the paper under review, ie firstly comment on the performance of the CAP and the stocktaking document under eight headings (‘objectives’) and then some more general remarks and conclusions.
Meeting CAP objectives The discussion concerning the free movement of goods rightly stresses the importance of the monetary compensatory amounts (MCAs). Both the Stocktaking and the authors’ discussion show that they are a step backwards. Obviously the real solution lies in greater unity, a closer coordination of economic and monetary policies. One cannot expect the CAP to work smoothly without these improvements. With regard to increasing productivitv, MacKerron and Rush state: ‘The CAP has had virtually no direct, and probably little indirect, effect on productivity’ (p 289). It is true that research, teaching and advisory services are essentially national and not common responsibilities (and the fact
that their levels of effectiveness are so different from one member country to another is a very real distortion of competition). It does appear however, both from micro-economic studies and from various more global analysis, that the price stability and price increases gained from the CAP have very strong effects on the investment decisions of farmers. Price policies have accelerated the adoption of new technology and increased the rate of capital formation. This has an evident influence on productivity (this reasoning is explicitly formulated in the Stocktaking). MacKerron and Rush recognise that labour productivity has ‘increased extremely rapidly’ (p 290). They attribute this to national structural policies rather than to the CAP. Measuring the consequences of policies raises structural several methodological difficulties exceeding the scdpe of this review. My hypothesis is stabilisation that price and price supports - obtained through national polices and later from the CAP - have created a significant incentive to structural changes, and have been more ’ Gordon MacKerron and Howard J. Rush, ‘Aqriculture in the EEC - taking stock’, F&d Policy, Vol 1 No 4, pp 2861 300.
85