Monthly Archives: August 2016

Kwashiorkor and the Great Protein Fiasco? Understanding Plant Proteins in Human Nutrition, Part 2

This post is the second of two written by Dr Caroline Hodges, University of Brighton. The first post discussed student preceptions and animal experiments.

In the 1930’s Cecily Williams identified a condition of advanced malnutrition which she called kwashiorkor, or ‘disease of the deposed child’. She made a cautious suggestion that the disease was associated with the loss of protein when a mother weans a toddler abruptly on the arrival of a new baby.

Little attention was paid to this discovery until the 1949 FAO/WHO Committee became involved in nutrient deficiency diseases and announced kwashiorkor was ‘one of the most widespread nutritional disorders in tropical and subtropical areas’. The condition was treated with skimmed milk, so it was assumed that it must be caused by a deficiency of protein (Brock and Autret, 1952).  Sathyamala (2016) is one of several with an interesting take on this:

‘This discovery of the cure coinciding with the availability of dry skimmed milk in the USA was a fortunate by-product of a domestic surplus-disposal problem. It was clearly more satisfactory in every respect to dump [skimmed milk] in developing countries than to have to bury it in the United States as was contemplated by the Department of Agriculture at one point’ (McLaren, 1974).’

Thereafter the contentious term ’the protein gap’ or ‘crisis’ was born.  This was first advocated when different committees believed child protein requirements were high in comparison with currently accepted values, but successive downward adjustments of the value over the years made it clear that children in areas where kwashiorkor was prevalent did not have a protein deficiency unless their overall energy intake was low (Briend, 2014). So although the symptoms of this disease are ‘persuasively consistent with protein deficiency rather than energy deficit, acute shortage of energy would, however, lead to use of protein as an energy source’ (Webb 2012, 283).

To her credit Williams later wrote ‘For the last 20 years I‘ve been spending my time trying to debunk kwashiorkor’ (McLaren, 1974).  Even today its aetiology and pathogenesis remain unclear, although textbooks authoritatively report it as a protein deficiency disease.

This apparent enormous ‘protein gap’ initiated a whole new field of research which also satisfied many commercial interests, specifically the mass production of protein-rich functional foods from sources such as fishmeal and microbes. In 1972 a ‘Protein Advisory Group’ was established to monitor this research. Sathyamala (2016) summarises the situation as follows:

‘..once the marketing of the surplus of skimmed milk in the USA had ceased to be a problem and given that the meat industry was unlikely to be able to play a role because of the levels of poverty in countries that were said to be afflicted with this condition, industry turned its attention to developing new, synthetic protein foods and exploiting them commercially….. Despite heavy funding and promotion, with few exceptions most of the protein-rich foods never reached commercial viability, with some products costing four times more than the original they were said to replace (McLaren, 1974).

One product which did succeed was Quorn but this is now marketed as a meat substitute for vegetarians in the West, rather than the high-protein food for needy children in developing countries (Webb, 2012).

Unfortunately, as McClaren noted (1974), ‘As a result, (of the protein gap) measures to detect protein deficiency and treat and prevent it by dietary means have been pursued until the present time. The price that has had to be paid for these mistakes is only beginning to be realised.’ Newman (1995) suggests ‘the unwarranted attention to protein ended up by wasting a great deal of time, money and lives’ and more recently Webb (2012, 279) refers to The huge costs both financial and medical, of exaggerating human needs’. He suggests ‘much of this effort was wasted and ‘directed towards solving an illusory problem’. McClaren (1974) went so far as to entitle his historically important article describing the so called protein gap: ‘The great protein fiasco’. 

Sathyamala (2016) explains the focus on kwashiorkor in the 1960’s by describing it as ‘the construction of a pure protein deficiency disease’, which shows how ‘scientific discourses in nutrition are shaped by the needs of capital and capital determines scientific truth’. She describes how:

’The entry of the pharmaceutical and food industries into functional food and supplements has created a new epistemic authority for truth claims whose strength lies in the ability to convince through propaganda with little pretence of a scientific base’.

The recommended dietary intake of protein has been progressively lowered, and Infant protein requirements decreased significantly from approx. 40g g/day in 1943 to 13g/day in 2005. In the 1970’s a recalculation at the stroke of a pen unwittingly closed the ‘protein gap’ and shattered the theory of the pandemic of ‘protein malnutrition.’

The former director of India’s Institute of Nutrition (Gopalan, 2007) made the following comment in his evocatively entitled article ‘Farms to Pharmacies: Beginnings of a Sad Decline’. ‘No arbitrary cocktail of synthetic nutrients’ — which he called a ‘blunderbuss pharmacy’ approach to undernutrition — ‘can substitute for a judicious combination of natural foods.  What an undernourished or overnourished population requires is access to appropriate and adequate amounts of conventional, regular foods and not their allegedly superior functional products… a diet of cereals, pulses, legumes, fruits and vegetables can meet these micronutrient requirements’.  Of course natural disasters and civil war etc., may deny this basic requirement to many, but supplements should not be the norm.

It appears that the ‘diverse, largely plant-based, diet of people in colonial territories was regarded as deficient in comparison to the flesh-based diet of the colonizers’ (Arnold, 1994), a notion which  has fuelled the ‘protein gap’ and still influences us today.

My interactions with students reinforce my fear this attitude cannot be readily divested, and the notion is, metaphorically speaking, in our genes.

After 10 years of lecturing in biochemistry and nutrition, when discussing plant based diets, I am still asked by the majority of students the question, ‘but where do they get their protein’? After 10 years of lecturing on proteins I am met with stunned faces when I say all foods (except gelatine) contain all essential amino acids. After 10 years of lecturing I still see exam answers saying we cannot survive without animal protein and 10 years of lecturing I am asked by some young men if 300 grams of protein a day will increase their muscle mass, despite the fact that only approx. 56g/day is recommended?

The rat experiments unwittingly started the train and perhaps Kwashiorkor was the fuel remorselessly pumped in.  It thundered along on tracks built by corporations and vested interests until it was finally derailed in the 1970’s. The trouble is, some people are still sitting on that train, undeterred, oblivious it may be heading on a collision course, unaware or indifferent to the reality that our choice of food can no longer be a personal matter, and the future of our grandchildren may depend on it.  The N8 AgriFood founding director Sue Hartley said: “We cannot grow our way out of this problem; we have to try to change the way that we behave.”

It is a widely-cited statistic that it takes ten kilograms of feed to produce one kilogram of beef, meaning an overall loss of nine kilograms of food produce. Increasing populations and climate change, which is partly due to our voracious appetite for animal produce (the so-called complete proteins), will have an explosive impact if they continue unabated. So how should we proceed? If we do nothing and global warming is as bad as predicted, our grandchildren will surely suffer the consequences. If, on the other hand, the deniers were correct, we may have wasted yet more time and money, but in this case, at least the next generations will have a future.

Sometimes pictures say it all and this is my favourite.

Gorilla protein image(Dan Piraro, 2010)

References

Arnold, D. (1994) ‘The Discovery of Malnutrition and Diet in Colonial India’, The Indian Economic and Social History Review, 31:1, 1–26

Bell, G. (1959) Textbook of Physiology and Biochemistry, 4th ed., Williams and Wilkins, Baltimore, p. 12

Bender, D. (2014) Introduction to Nutrition and Metabolism, 5th ed. Chapter 9 (CRC press) p255

Briend, A. (2014) Kwashiorkor: still an enigma – the search must go on. In: CMAM Forum Technical Brief

Brock, J.F. and Autret, M. (1952) Kwashiorkor in Africa, World Health Organization Monograph, Series No. 8. Geneva: WHO

Gopalan, C. (2007) From ‘Farms to Pharmacies’: Beginnings of a sad decline. Econ Pol Wkly, 42: 3535-3536

Hartley, S. (2016) Scientists hungry to deliver food system paradigm shift, BBC article

Ioannidis, J. (2012) Extrapolating from animals to humans, Sci Transl Med, 4: 151

McLaren, D.S. (1974) ‘The Great Protein Fiasco’, Lancet, 304(7872), 93-96

McLaren, D.S. (2000) ‘The Great Protein Fiasco Revisited’, Nutrition, 16: 464-5

Miller, D and Payne, P. (1969) Assessment of protein requirements by nitrogen balance. Proceedings of the Nutrition Society, 28: 2, 225-234

Newman, J.L. (1995) ‘From Definition, to Geography, to Action, to Reaction: The Case of

Protein-Energy Malnutrition’, Annals of the Association of American Geographers, 85: 2,233–45

Osborne, T. and Mendel, L. (1914) Amino-acids in nutrition and growth. J Bio Chem, 17: 325-49

Rand, W.M, Pellett, PL. Young, V.R. (2003) Meta-analysis of nitrogen balance studies for estimating protein requirements in healthy adults, American Journal of Clinical Nutrition, 77: 109-127

Reeds, P.J. (2000) Protein nutrition of the neonate, Proc Nutr Soc, 59:1, 87-97

Rose, W. (1948) Comparative growth of diet containing ten and nineteen amino acids, with further observation upon the role of glutamic and aspartic acid, J Bio Chem, 176: 753-62

Sathyamala, C. (2016) Nutritionalizing Food: A Framework for Capital Accumulation. Development and Change 47:4, 818-839.

Webb, G. (2012) Nutrition: Maintaining and improving health, 4th ed. Chapter 11, Taylor & Francis Group, LLC

Young, V and Pellett P. (1994) Plant proteins in relation to human protein and amino acid nutrition. Am J Clin Nutr, 59 (suppl):1203S–1212S

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The Great Protein Fiasco? Understanding Plant Proteins in Human Nutrition

This article by Dr Caroline Hodges is shared in two parts, the second part will be posted on Thursday the 4th of August 2016. Caroline teaches nutrition at the University of Brighton and is a member of the BSUFN steering group.

The following description of what we should eat might surprise many people: “Households should select predominantly plant-based diets rich in a variety of vegetables and fruits, pulses or legumes, and minimally processed starchy staple foods.”

You would be forgiven for thinking this comes from some vegan, vegetarian or alternative ‘nuts and sandals’ health group, but the source is The World Health Organization and the Food and Agriculture Organization of the United Nations.

In my previous blog I presented the so called ‘myths’ relating to dietary protein which I encounter in biochemistry and nutrition textbooks. In this one I would like to discuss two specific events which contributed to the perpetuation of these myths and consider the long term negative impact on our health and the environment. First I will describe the early experiments on rats to determine optimum protein requirements and second, I will outline the discovery and repercussions of a disease called kwashiorkor.

Before I unravel the effect of these two events I would like to explain what initiated my concerns about this subject. The following multiple choice question is used in my nutrition exam. (Correct answer is C, but A is the answer given by approx. 50% of students).

What is the primary source of protein for most of the world’s population?

  1. Meat
  2. Dairy
  3. Grains and vegetables
  4. Fruits

The number of students who get this wrong always surprises me, despite lectures which should lead them to the correct answer and me going so far as to announce that this, or a similar question, will be in the exam! Every year I go further; this year I told the students that approx. 50% of students might get the answer wrong, in the vain hope of alerting them to this error.

It is not absenteeism from lectures that causes the mistake, so I find it both disturbing and revealing to ponder the reason. It seems so many students, even those at medical school, are so convinced by our need for animal protein that whatever else they read does not register. I still find comments in the exam suggesting that we cannot survive without animal protein and in its absence we become ill. It seems the perceptions of my students (and the public) have been shaped by decades of poor information on this subject.  It does not help that textbooks still describe proteins as ‘complete’ (animal sources) and ‘incomplete’ (plant sources). The insidious and seemingly pervasive implication being that we cannot survive without the ‘complete’ ones. After all, these textbooks can’t be wrong, can they? Most dictionaries define incomplete as ‘lacking a part’, but as applied to plant protein this is not so, every one of the essential amino acids is present, just in varying proportions in different plants. If we only ate one food item all day, every day, that proportion would be hugely important, but in most countries this is unlikely to be the case. So what has caused this misunderstanding?

Rat experiments

The first of the two subjects I would like to describe is related to animal experiments conducted over a century ago to determine the optimum protein requirement for humans, the legacy of which still prevails. The myth, described by (Young et al, 1994) is as follows:

‘Animal procedures can provide good indices of the human nutritional value of food proteins’.

In 1914 Osborne and Mendel studied the protein requirements of laboratory rats and demonstrated nutritional requirements for the individual amino acids of which proteins are made. At that time it was not known that rats have much greater protein requirements than humans (Rose 1948) because, by comparison, they have a much more rapid tissue growth. This difference in protein requirements is further demonstrated by the comparison of breast milk from both species; the protein content of rat breast milk is 10 times greater than the milk intended for human babies (Bell 1959; Reeds 2000).

The other damaging outcome of this animal-based work is the concept of complete and incomplete proteins, also referred to as first class or superior (from animal sources) and second class or inferior (from plants sources) proteins. These descriptions are based on the premise that animal products provide the most ideal pattern of essential amino acids for humans, which is now known to be incorrect. These animal experiments and subsequent definitions of protein quality are much less relevant in human nutrition, and our metabolic requirements are quite different.  This is substantiated by the difficulty in demonstrating in normal healthy adults any difference in nitrogen balance (an indication of appropriate protein intake) between diets based on plant protein and those based on animal sources (Rand et al, 2003).

So over misinterpretation of animal experiments (Ioannidis, 2012) and inappropriate extrapolation to humans has encouraged both inflated estimates of protein requirements, especially in children, and erroneous distinctions between the quality of plant and animal protein. The estimated protein needs of children are now half as much as they were in the 1940’s and it is becoming apparent that the much greater risk (in the West at least) is over-consumption of protein.

It seems that comparisons of ‘complete’ and ‘incomplete proteins’ are much more academic than practical and require rethinking, as described so well by Bender, (2014, 255):

‘While protein quality is important when considering individual foods, it is not relevant when considering total diets because different proteins are limited by amino acids, and hence have a relative excess of others. The result of mixing different proteins in a diet is an unexpected increase in the nutritional value of the mixture…..The average Western diet has a protein score of 0.73,  whilst the poorest diets in developing countries, with a restricted range of foods, and very little milk, meat, or fish, have a  protein score of 0.6’. (The difference is minimal.)

Miller and Payne (1969) concluded that ‘almost all dietary staples contain sufficient protein to meet human needs and that even diets based on very low protein staples are unlikely to be specifically protein-deficient. Webb (2012, 279) points out that since 1969 this view has become the nutritional consensus. It seems unfortunately that this message has not permeated to the lay public.

The second event known to have a huge influence on policy and recommendations led to what is called the ‘great protein fiasco’. Caroline’s article on the ‘great protein fiasco’ will be posted on Thursday the 4th of August 2016.

References

Arnold, D. (1994) ‘The Discovery of Malnutrition and Diet in Colonial India’, The Indian Economic and Social History Review, 31:1, 1–26

Bell, G. (1959) Textbook of Physiology and Biochemistry, 4th ed., Williams and Wilkins, Baltimore, p. 12

Bender, D. (2014) Introduction to Nutrition and Metabolism, 5th ed. Chapter 9 (CRC press) p255

Briend, A. (2014) Kwashiorkor: still an enigma – the search must go on. In: CMAM Forum Technical Brief

Brock, J.F. and Autret, M. (1952) Kwashiorkor in Africa, World Health Organization Monograph, Series No. 8. Geneva: WHO

Gopalan, C. (2007) From ‘Farms to Pharmacies’: Beginnings of a sad decline. Econ Pol Wkly, 42: 3535-3536

Hartley, S. (2016) Scientists hungry to deliver food system paradigm shift, BBC article

Ioannidis, J. (2012) Extrapolating from animals to humans, Sci Transl Med, 4: 151

McLaren, D.S. (1974) ‘The Great Protein Fiasco’, Lancet, 304(7872), 93-96

McLaren, D.S. (2000) ‘The Great Protein Fiasco Revisited’, Nutrition, 16: 464-5

Miller, D and Payne, P. (1969) Assessment of protein requirements by nitrogen balance. Proceedings of the Nutrition Society, 28: 2, 225-234

Newman, J.L. (1995) ‘From Definition, to Geography, to Action, to Reaction: The Case of

Protein-Energy Malnutrition’, Annals of the Association of American Geographers, 85: 2,233–45

Osborne, T. and Mendel, L. (1914) Amino-acids in nutrition and growth. J Bio Chem, 17: 325-49

Rand, W.M, Pellett, PL. Young, V.R. (2003) Meta-analysis of nitrogen balance studies for estimating protein requirements in healthy adults, American Journal of Clinical Nutrition, 77: 109-127

Reeds, P.J. (2000) Protein nutrition of the neonate, Proc Nutr Soc, 59:1, 87-97

Rose, W. (1948) Comparative growth of diet containing ten and nineteen amino acids, with further observation upon the role of glutamic and aspartic acid, J Bio Chem, 176: 753-62

Sathyamala, C. (2016) Nutritionalizing Food: A Framework for Capital Accumulation. Development and Change 47:4, 818-839.

Webb, G. (2012) Nutrition: Maintaining and improving health, 4th ed. Chapter 11, Taylor & Francis Group, LLC

Young, V and Pellett P. (1994) Plant proteins in relation to human protein and amino acid nutrition. Am J Clin Nutr, 59 (suppl):1203S–1212S