Nutrition Discussion Forum
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British Journal of Nutrition (2003), 90, 233–238 DOI: 10.1079/BJN2003865 q The Author 2003 Nutrition Discussion Forum Why do we not make more medical use of nutritional knowledge? How an inadvertent alliance between reductionist scientists, holistic dietitians and drug-oriented regulators and governments has blocked progress David Horrobin Laxdale Ltd, Kings Park House, Laurelhill Business Park, Stirling FK7 9JQ, Scotland, UK Many population subgroups that are at high risk of ill- rarely prescribed, for those who do need it: the socially health have multiple micronutrient deficits. These sub- and financially deprived, the elderly poor, the mentally groups include the elderly, the socially and economically ill, those in prisons, and those at high risk of obesity and deprived, hospital patients and the mentally ill, among cardiovascular disease. The evidence of its value is con- others. Placebo-controlled trials of simple micronutrient siderable, so why do we so rarely employ such a safe, supplements have shown that they can improve immune low cost and effective remedy? The answer lies in a mix function and reduce time suffering from infections in of scientific reductionism, holistic obscurantism, regulatory older people, reduce length of stay in hospital and improve rigidity, the absence of commercial incentive, and a failure clinical outcomes, improve pregnancy outcomes and of the imagination on the part of government. reduce violent behaviour. If these findings could be trans- ferred to the general population, the improvement in health and the reductions in cost of the service would be The value of nutrition immense. Three main factors, however, are blocking both further research and the implementation of what we The first half of the last century was a golden age of nutri- already know. These are: (1) reductionist attitudes among tional biochemistry, when most of the essential nutrients scientists who want to study only one micronutrient at a were identified, their acute deficiencies understood and time; (2) holistic attitudes among dietitians and nutrition- their value to humankind unequivocally demonstrated. ists who, with a lack of realism, want the relevant groups But so lost has that hard-won knowledge become that to change diet rather than take supplements; (3) govern- most modern medical students and young doctors, who ments who have created a regulatory framework that is know much molecular biology of uncertain relevance, commercially inimical to the development of multinutri- can no longer summarise even in broad outline the major ents to treat disease. All of these attitudes need to change metabolic pathways, cannot pinpoint the multiple locations if we are going to apply what we already know about nutri- at which essential nutrients work, and cannot describe with tion to the improvement of human health. But if attitudes any clarity the consequences of gross deficiency. do change we could see the fastest ever, and also the Moreover, there is a lack of awareness of three lessons cheapest, improvement in human health. from that era which used to be well known. The three Suppose we were to discover a new drug that we could be lost lessons are as follows. certain would never produce an important adverse reaction, (1) Even within an inbred strain of animals there are large would prevent and relieve a great deal of suffering due to variations in the minimum amount of an essential depression, violence, cardiovascular disease, infections, nutrient required for health. When a large group is inflammatory disease and a range of other conditions, fed on diets of progressively increasing deficit in a and could be sold at a trivial cost when compared with particular nutrient, some animals will become sick most other medical interventions: would we rush to intro- when dietary intake has been only slightly reduced, duce such a drug into clinical medicine, would govern- while others may not become ill until the nutrient ments be keen to market it and promote its use, would has been largely depleted. Variations in daily nutri- doctors be keen to prescribe it? The answer to all these tional requirements among non-inbred humans sub- questions is probably no. For we have such a drug and it jects are likely to be considerably greater, as is is hardly used by those who could most profit from it. suggested by experiences of prisoners in Second The drug is a combination of all known essential World War camps where, despite similar conditions nutrients present at levels approximately equivalent to the some succumbed rapidly to nutritional deficits while official national recommended daily allowances. It is a others remained healthy (Duncan, 1982; Venables drug which is widely used at their own expense by the et al. 1985; Roland & Shannon, 1991). affluent and relatively affluent middle classes who do not (2) Because most essential nutrients are required for the need it, and therefore benefit little from it, because they functioning of most tissues, a deficit of a single essen- already consume most of the nutrients in adequate quan- tial nutrient will cause loss of function of every tissue tities in their diet. It is a drug that is rarely used, and in the long run. But in the shorter term, the genetic 234 D. Horrobin and environmental background of the individual (Horrobin, 2002a,b). These common nutritional deficits will determine which organ breaks down first. Thus, therefore have potentially serious effects on human in pellagra, some people will first develop dermatolo- health, and especially mental health. gical symptoms, some gastrointestinal symptoms and some a psychiatric disorder. Alternatively, in scurvy, Responses to the problem depression is commonly the first symptom, or it may be a thrombotic disorder, or a dermatological disorder, If the problem is as I have suggested, then it is an issue that or a Sjogren’s syndrome-like condition. The permu- in theory could produce huge health returns for minimal tations and combinations and the variety of symptoms expenditure. Why has this not happened? Multiple forces, are almost infinite. But in each case complete cure fol- coming from different directions have inadvertently con- lows the prescription of the single missing nutrient. spired to ensure a near-complete failure to apply existing (3) Our knowledge base about daily requirements is knowledge to generate an appropriate solution. seriously defective when it comes to requirements for time periods of $1 year in any population other The reductionist scientist’s position than fit young males. Almost all our solid evidence- based knowledge relates to short-term experiments in This comes in various guises, but the most important argu- healthy male volunteers. When it comes to life-long ments against doing anything are the following. needs in broader population groups, our understanding (1) We do not yet know enough about the health conse- is inevitably less secure, and our recommendations quences of the nutritional deficits in the different must be made cautiously. populations. Provide the necessary support and we will collect the information. The evidence for deficits (2) In order to understand clearly what is happening we must study one variable at a time. We must therefore The evidence that many individuals from various forms of set up a series of trials in which a single nutrient is deprived backgrounds may suffer nutritional deficits is now compared with placebo, preferably in those who can strong (e.g. McWhirter & Pennington, 1994; Bailey et al. be shown to be deficient in such a nutrient. Again, 1997; Ames & Wakimoto, 2002; Horrobin, 2002a). given the support, we will set up a trial programme During the lifespan this is true of many otherwise normal that will last the lifetimes of many researchers. young, middle-aged and elderly people as they fail for var- ious reasons to eat a balanced diet. It is true of the mentally ill, especially of those with psychoses, whose diets may be The maternalist dietitian’s and nutritionist’s position very strange. It is true of large numbers of socially and economically deprived individuals who, by reason of edu- We know that these groups of people are deprived, and so cation, preference, or financial deficit, may be unwilling or what we must do is persuade them to eat proper meals unable to eat foods that give the essential nutrients needed. without giving them the resources to do so. The faddish It is true of many patients who are admitted to hospital. adolescents, the incapacitated elderly, the socially and edu- It may even be true of some of the affluent, whose hurried cationally deprived and the mentally ill must all shop more and stressful lifestyles prevent them giving due consider- intelligently, must eat four colour meals and must endea- ation to proper nutrition. vour to consume a varied diet with twenty-three portions Whatever the reason, large numbers of individuals in of fruits and vegetables each day. any society are deficient in one or more essential nutrient. In particular individuals the nutrients affected differ, but The drug-oriented regulator’s position deficits of folic acid, vitamin B12, pyridoxine, Zn and Se are common, and those of many others not particularly If it were possible to demonstrate that a nutrient combi- rare (e.g. Ong et al. 1983; Black et al. 1986; Bunker nation had efficacy in a particular disease we would be & Clayton, 1989; Bates et al. 1999; Davies et al. 1999; happy to give that combination a pharmaceutical product Pentieva et al. 1999). In an affluent small European city, licence. But because we know that many past drug combi- for example, about half of all patients with schizophrenia nations have contained inactive ingredients and because the were found to be vitamin D-deficient (Fleischhacker et al. public must be protected against inappropriate and poorly 2002). manufactured products, we will grant a licence to market Since normal biochemistry is essential if the human body a product only if it is possible to demonstrate by appropri- is to respond effectively to disease and to its treatment, and ate trials that every ingredient is necessary.