Consider and evaluate how Nutritional Therapy relates to the Functional Medicine Model.




When we consider the role of Nutritional Therapy (NT) within the Functional Medicine (FM) Model it is important to first examine the historical context of both natural and conventional medicine in the Twentieth Century and to discuss the development and evolution of modern lifestyles and disease. I hope this discussion will build upon the historical context of medicine to examine how modern lifestyles and chronic disease have created the need for a new approach to healthcare. We must examine the  core principles of both FM and NT to understand their common ideals as well as the obstacles, which prevent immediate, mainstream integration.



In contrast with the conventional ‘organ-systems’ approach to medicine, FM looks at the whole body to identify internal systems imbalances + factors such as lifestyle, nutrition and toxins, which act as pre-cursors to long term chronic disease. NT is the science of gastrointestinal dysfunction, a key indicator in the onset of chronic disease.  The primary aim of NT is to restore homeostasis + balance to the body through the regulation of a healthy diet, positive lifestyle changes and the application of tailored recommendations based on the unique biochemical make-up of the individual.

Here I aim to examine  some of the core imbalances; diet, genetic individuality, environmental toxicants + stress and how NT and FM are best served to reverse them. By incorporating NT within the framework of the FM model, the best practices of holistic medicine and an evidence-based foundation for health can be achieved.





NT can trace its’ roots to the early principles of Naturopathy, defined in the late 1800’s by it’s founder Benedict Lust (1918) as; “The natural system for curing disease… based on a return to nature in regulating the diet, breathing, exercising…and so raise the vitality of the patient to proper standards of health”. Naturopathic principles included the importance of a healthy diet as integral to harnessing the healing power of nature and natural cures. After the initial rapid growth of the movement in the 1920’s and 30’s, Naturopathy declined in popularity as advancements in science took hold and breakthrough discoveries on the aetiology of infectious disease led to the emergence of the current conventional medicine model. 


In 1928 a medical scholar by the name of Dr. Alexander Fleming made a world-changing discovery in his laboratory at St. Mary’s medical school in London. “Dr. Alexander Fleming’s discovery of penicillin and the subsequent development of antibiotics were the most significant advances that revolutionised the practice of medicine.” (Wong, 2003). It was the outbreak of the Second World War in 1939 and the subsequent number of infectious and bacterial diseases caused by battlefield conditions, which led to the mass production of penicillin. With production facilitated by the financial backing of the influential Rockefeller Foundation in the United States antibiotic drugs were hailed as the silver bullet in the fight against infectious disease (American Chemical Society, 1999). Their immediate impact changed the face of medicine for many years to come and this same medical model of symptom diagnosis and drug prescription perpetuates to this day. 




In recent years, we have seen the rise in non-communicable dieseases; long-term chronic conditions such as diabetes, Alzheimer’s, cardiovascular disease, cancer and obesity, which cannot be cured with a single pill. These diseases develop over a long period of time and are the biggest threat to our mortality. According to the World Health Organization;


Chronic diseases are diseases of long duration and generally slow progression. Chronic diseases, such as heart disease, stroke, cancer, chronic respiratory diseases and diabetes, are by far the leading cause of mortality in the world, representing 73% of all deaths (by 2020). Out of the 36 million people who died from chronic disease in 2008, nine million were under 60 and ninety per cent of these premature deaths occurred in low- and middle-income countries.




The conventional model of medicine, with it’s silver bullet approach of one-fit drug prescription + minimal patient interaction, is not equipped to root out the underlying cause of chronic disease, nor identify the complex, myriad factors including lifestyle, diet and genetic pre-disposition, which precede them. 


What can be surmised from the rapid changes in healthcare which took place during the 20th Century? The advancements of science in medicine and the rise of chronic disease have led to the need for a new approach to managing our health. FM is a new approach; it encompasses the best of evidence-based scientific methods alongside the holistic and naturopathic principles of treating the whole person rather than just the symptoms of disease. This evidence-based approach is of the utmost importance if it is to earn the recognition of its mainstream peers.




David Jones, president of The Institute for Functional Medicine (IFM) (2008a) stresses the importance of FM; “The key to reversing the rapidly spreading epidemic of chronic disease is to address the underlying causes and solutions for chronic disease, which are primarily driven by the lifelong, daily interaction among an individual’s genetics, environment and lifestyle choices”. Unlike conventional medicine, which traditionally focuses on the diagnosis and symptom treatment of acute conditions, FM looks at the complex interactions affecting an individual. The IFM (2008b) states, “under the rubric of personalized medicine lie many other complex issues relevant to biochemical, physiological, genetic, and environmental individuality that must also be attended to if we hope to reverse the modern epidemic of chronic disease and assist patients toward healthier lives”. These external interactions and influences cause an imbalance to homeostasis in the body, which ultimately leads to allostasis, a change in the status of cell function. Allostasis; meaning stability through change, can have severe consequences to our health when the overall allostatic load becomes more than the body can bear. As stated by Nicolle and Woodriff Beirne, (2010, p.31);


In allostasis, the body has a relatively high level of flexibility in response to challenges but after a while the maintenance of allostasis changes + the body fails to revert to ‘normal status’, leading to overload + health consequences. These are likely to be pathological in nature, for example hypertension, obesity, type 2 diabetes, addictive behaviours and psychological problems.


During an initial appointment a FM patient will typically have a long initial consultation with a physician discussing lifestyle factors including their health history, living habits, potential toxin exposure and family history of illness. This thorough examination and patient profile aims to identify unique areas of imbalance and dysfunction, for example; “improving the patient’s sleep beneficially influences the immune response, melatonin levels, T-Cell lymphocyte levels, and often help decrease oxidative stress throughout the organism”. (IFM, 2008c).


One condition can be caused by several imbalances; conversely one imbalance can cause several conditions. It is the job of the physician, together with the patient, to identify and remedy the key imbalances in the individual. Jones et al. (2013) propose seven basic principles of FM, including the acknowledgement of each human being as having a unique biochemical makeup; treating the person and not the disease; acknowledging the interconnection between the mind, body and spirit and addressing those interconnections; acknowledging the importance of health as a vital force for good, encouraging a longer health span, not just life span; and finally, keeping up to date with the latest scientific research. It is this uniqueness of the individual and the acknowledgement of the role of external environmental factors, which sets FM apart from its conventional counterpart. 





So, we've had a look at the FM model, let's now examine the role of NT in more detail. NT comes under the umbrella of Complementary and Alternative Medicine (CAM). It currently functions outside the remit of the conventional medicine model, yet it has many of the same underlying principles outlined in the approach to FM. Practitioners are trained to follow holistic principles, gathering information from all areas of a patients’ life and health history and making recommendations based on factors relating to lifestyle, stress, exercise and diet (Nutritional Therapy Council, 2013).


NT + the role of the nutrients we absorb and the toxins we eliminate, has emerged as a complex and integral process of restoring health and homeostasis within the body. Chronic disease is often linked to a dysfunction of both our innate and adaptive immune systems, leading to inflammation and immunopathology (Ash, 2010, p.256). The biochemical epidemiology of nutrition plays a vital role in the prevention of chronic disease. The connection between nutrition + health acts as a continuous feedback loop within the body. The foods that we consume have direct influences on the function of cells within our bodies and the functional changes imposed upon those cells in turn determine the nutritional needs specific to the individual. To further clarify, the catabolic process of metabolizing the food we eat has a direct impact on the anabolic processes of metabolism within our bodies. As explained by Seeley et al. (2006, p.940);


‘Metabolism is the total of all the chemical reactions that occur in the body. It consists of anabolism, the energy requiring process by which small molecules are joined to form larger molecules and catabolism, the energy –releasing process by which large molecules are broken down into smaller molecules. 


For example, the catabolic process of glycolysis (glucose conversion) synthesizes Adenosine Triphosphate (ATP) within the body. Mitochondria surrounding the cell nucleus convert this energy from our food into ATP, the energy required to perform life-sustaining functions throughout the human body. This understanding of the chemical processes of converting one substance into another for use in the body, known as metabolic pathways, has a direct influence on gene expression and as such is both a complex and uniquely individualized process which effects the whole body, mind and spirit. 

After a thorough assessment of the individual and with laboratory analysis of key markers such as microbial aetiology, vitamin and mineral screening and allergy testing, practitioners can make informed and comprehensive nutritional recommendations with the aim of promoting optimum health. 



It is evident that NT shares many of the same core principles as FM but its main detraction to date has been the lack of evidence-based research to substantiate its’ claims. Despite the universal acknowledgement of the benefits of a healthy diet, specific nutritional recommendations have been fraught with ambiguity due to the virtually impossible task of gathering accurate information about an individuals’ food and drink intake within the parameters of a clinical trial. Whilst nutritional intervention must also take into account the differences in the metabolic make-up of the individual (Byers, 1999), together, the tenets of dose and eligibility are compromised. L. Thomas (2013, p.1304-1308) continues; “Unfortunately, this means that many doctors will ignore all of the studies of diet and focus only on the studies of drugs. As a result, those doctors end up writing prescriptions for drugs instead of teaching their patients how to eat properly—even if the dietary intervention works better than the drugs”.  




As NT has come to recognise the importance of evidence-based research in order to gain recognition within the mainstream medicine model, advancements in nutrigenomics and psychoneuroimmunology are providing the evidence to advance NT beyond the existing constraints of differential diagnosis. Tang et al. (2009) negotiate the benefits of genomics, stating;


Genomics, transcriptomics, proteomics, metabolomics, epidemiological data and microbial data provide different angles to our understanding of gene-environment interactions and the determinants of disease and health. The goal + the challenge is to integrate these very different types of data and perspectives of disease into a global model suitable for dissecting the mechanisms of disease and for predicting novel therapeutic strategies.


This combined approach of the thorough profiling of the patient, combined with the latest scientific technologies to isolate and identify unique imbalances within an individual, enables NT to exist comfortably within the framework of FM.




Beyond the direct consumption or deficiency of nutrients in our diet, key catalysts for imbalances within the body are the toxicants in the environment around us. As the body is a complex web of interconnections and communications between the mind and the body, external factors, such as stress and the environment play an important role in the functioning of the digestive system, nutrient intake and optimum functioning of all detoxification systems of the body. As previously discussed, the body becomes susceptible to disease when one or several factors cause allostatic overload, which can lead to the onset of chronic disease.




Psychoneuroimmunology is an emerging field of science of great interest to both FM practitioners and NTs. It studies the role of mind-body medicine and the physical manifestations of our emotions on our immune, endocrine and digestive systems, the negative effects of which can result in chronic disease. Psychoneuroimmunology is a biological process of cause and effect. Nutrition has a key role to play in restoring the imbalances, which are produced by modern lifestyle factors such as stress and environmental toxins. The stress response is known to work in the body as a negative feedback loop. As the brain acknowledges a stressful situation it switches into fight or flight mode, producing the stress hormones known as corticotrophin releasing hormone (CRH) and arginine-vassopressin (AVP). CRH stimulates the pituitary gland to release adrenocorticotrophic hormone (ACTH), prompting the release of cortisol and adrenalin into the bloodstream and activating what is known as the Hypothalamic-Pituitary-Adrenal Axis. Ongoing stimulation and release of cortisol into the bloodstream can cause physiological changes within the body, sending messages back up to the brain to reduce the production of CRH (UWL, 2013). The effects of excess cortisol secretion can lead to immune dysfunction (Bennet, P. 2013). This feedback loop is the cornerstone of psychoneuroimmunology. As an individual experiences a perceived stressful scenario, neurons are stimulated in the brain and chemicals are released to cause biological effects within the body. The hormones secreted by the pituitary gland are responsible for regulating homeostasis within the body and control many functions, including blood pressure, metabolism, water-regulation and pain relief. Tsigos (2002) states;





Activation of the stress system leads to behavioral and peripheral changes that improve the ability of the organism to adjust homeostasis and increase its chances for survival…. Conversely, activation of the HPA axis has profound inhibitory effects on the inflammatory/immune response because virtually all the components of the immune response are inhibited by cortisol.


If stress and environmental toxins are the triggers for these biochemical processes within the body, what can be done to eliminate those triggers? The answer lies in the healing powers of nature and takes us back to the fundamental principles of naturopathy and a holistic approach to health. To combat the detrimental effects of stress we need to find ways to elicit a "relaxation response" which has the exact opposite effect of the "fight or flight' response in our bodies. (Benson, 1975). By lowering our blood pressure, slowing our breathing and calming our minds we have the ability to cause a positive effect on the hypothalamic-pituitary-adrenal axis and expedite good health. A trickle down effect is now being promoted in holistic nursing across the NHS (Lorentz, M. 2006). Lorentz believes that incorporating a mind body approach to nursing brings about a more positive outcome to patients’ illnesses. Meditation, yoga, lifestyle counseling and a health promoting diet of whole, natural foods are all elements of the underlying principles of naturopathy with the aim of restoring homeostasis.



Stress, within the context of modern lifestyles is relatively easy to define. The fast pace of life, large mortgages, financial uncertainty, high rates of divorce to name a few examples, all lead to higher rates of stress. This must be managed through mindful and health promoting techniques, such as a healthy diet, exercise and rest to prevent harmful pathogenesis from developing. Another stress on our bodies, less easy to define, is the increasing effect of harmful toxins proliferating in our environment. Thousands of man made chemicals are released into the atmosphere every year and they are impossible to avoid. From cigarette smoke to pesticides and the everyday toxicants found in our home; Bisphenol A (BPAs), Dioxins, Phthalates, Lead and Asbestos, our bodies are subjected to the harmful effects of these chemicals on a daily basis. (Environmental Protection Agency, 2013). The human body has its own advanced detoxification plant in the form of the liver, the kidneys the skin and the lungs. However, long-term exposure to toxicant agents will impair the efficiency of this system (Ha et al., 2003). Much can be done to decrease the toxic load on our bodies, by altering our lifestyle and nutritional habits. By stopping smoking and eating a healthy diet of organic food, which has not been over-processed with chemicals, we can make a significant difference to lowering toxic stress on the body. By reducing our use of heating food in plastic food containers or under plastic wrap, swapping non-stick pans for enamel or stainless steel and limiting the use of food in tins we reduce exposure to chemicals, which can leach out, into our food. Michael Lyon (2013), in his paper on Functional Toxicology, explains that a detoxification lifestyle is needed to reduce our exposure to ‘toxicologic factors and improve the efficiency of … detoxification mechanisms.” He goes on to explain the importance of nutrition, supplements, exercise and rest as a specific means of “reducing toxic body burdens”.




We have discussed how the rapid rise in long-term chronic disease has led to a need for change in the conventional approach to medicine. Advancements in science and a greater understanding of the role of nutrients, the effects of stress and environmental toxins, reveal that a thorough examination of the whole body in the restoration of health is necessary, that is the physical body, the mind and the lifestyle factors unique to each of us which play a role in determining the underlying causes of disease. The incorporation of research and scientific methodology is vital to enhancing both the reputation of complementary styles of medicine and also understanding the genomic differences in every individual and applying a unique approach to implementing interventions. My research concludes that an integrated approach to medicine is vital in addressing these modern-day concerns, however the allopathic model is deeply ingrained on our psyche and change will not come easily. A report, commissioned in Australia, looked at some of the challenges of a fully integrated medical practice, which was established in 2006. The results of its’ findings show that despite diversity of practitioners at the clinic, the biomedical doctors remained the main income generators for the business, limits were imposed by the lack of fully integrated computer systems for sharing notes between practitioners and for keeping prescriptions of both pharmaceutical drugs and natural-medicine products, making it hard to flag potential negative interactions. Cost was also an issue as most insurance companies only covered the cost of biomedical care. “Comments from the staff questionnaire indicated that biomedical dominance also affected team-building negatively.” (Hunter et al. 2012). The results are of interest because it shows, that despite all the emerging evidence in the field of nutrition, complementary therapy and FM, there are many practical obstacles to overcome if allopathic medicine is to be remodeled on a wide scale.




In conclusion, there are two distinct philosophies and models of health care today, the conventional, allopathic model and the holistic, complementary model. While conventional care has served us well during the past 100 years, eradicating much of the infectious disease that killed our forbears, the world has evolved at a dizzying pace and environmental factors such as man-made chemicals, processed food and stress-fueled lifestyles have led to a new wave of long-term chronic disease which is not best served by the silver bullet approach of allopathy. An integrated approach to medicine, the so called FM model, aims to incorporate the very best of both systems, applying the advanced discoveries of pharmaceutical drugs and procedures to the holistic approach to the human body as an interconnected network of physical and psychological pathways which need restoring to harmony. This harmony, or homeostasis within the body is the key to optimum health and reversing the inherent pathogenesis caused by twenty first century lifestyles. NT is vital to this process. The food we eat produces the energy required to build and maintain our bodily systems as well as to service and uphold our detoxification systems. A healthy diet of whole foods and best quality produce is key to maintaining a healthy body and an individualized programme of nutritional intervention is key to restoring optimum health. 





American Chemical Society (1999) International Historical Chemical landmarks. Discovery and Development of penicillin. [Online]. Available at: [Accessed: 10 January 2014].


Ash, M. (2010) Dysregulation of the Immune System: A gastro-centric perspective. In Nicolle, L. and Woodriff Beirne, A. (eds.) Biochemical Imbalances in Disease, London: Singing Dragon, p.256-268. 


Bennet, P. (2013) Placebo and the Power to Heal. In Pizzorno, J.E. and Murray, M.Y. (eds.) Textbook of Natural Medicine. Missouri: Elsevier Churchill Livingstone, p.69-87.


Benson, H., Beary, J.F. and Carol, M.P. (1974) The relaxation response. Psychiatry: Journal for the Study of Interpersonal Processes, 37(1), p.37-46.


Byers, T. (1999) The role of epidemiology in developing nutritional recommendations: past, present, and future. The American Journal of Clinical Nutrition, 69(6), p.1304-1308.


Environmental Protection Agency (EPA) (2013) Chemical Safety Research [Online]. Available at: [Accessed: 11 January 2014].


Ha, H., Kim, K., Yeom, Y., Lee, J. and Han, P. (2003) Chronic restraint stress massively alters the expression of genes important for lipid metabolism and detoxification in liver. Toxicology Letters, 146(1), p.49-63.


Hunter, J., Corcoran, K., Phelps, K. and Leader, S. (2012) The Challenges of Establishing an Integrative Medicine Primary Care Clinic in Sydney, Australia. The Journal of Alternative and Complementary medicine, 18(11), p.1008-1013.


Jones, D.S., Quinn, S. and Galland, L. (2013) Functional Medicine: A Twenty-First Century Model of Patient Care and Medical Education. In Pizzorno, J.E. and Murray, M.Y. (eds.) Textbook of Natural Medicine. Missouri: Elsevier Churchill Livingstone, p.8-17.


Lorentz, M.M. (2006) Stress and Psychoneuroimmunology Revisited: 

Using mind-body interventions to reduce stress. Alternative Journal of Nursing, 7(11), [Online]. Available at: [Accessed: 13 December 2013].


Lust, B. (1918) Universal directory of naturopathy. New Jersey: Lust Publications.


Lyon, M. (2013) Functional Toxicology. In Pizzorno, J.E. and Murray, M.Y. (eds.) Textbook of Natural Medicine. Missouri: Elsevier Churchill Livingstone, p.475-487.


Nicolle, L. and Woodriff Beirne, A. (2010) The Healthcare Futurescape: How did we get here and where are we going? In Nicolle, L. and Woodriff Beirne, A. (eds.) Biochemical Imbalances in Disease, London: Singing Dragon, p.31-33. 


Nutritional Therapy Council (NCT) (2013) The basis of Nutritional Therapy. [Online]. Available at: [Accessed: 11 January 2014].


Seeley, R.R., Stephens, T.D. and Tate, P. (2006) Anatomy and Physiology. 7th ed. New York: McGraw Hill.


Tang, J., Yew-Tan C., Oresic, M. and Vidal-Puig, A. (2009) Integrating post-genomic approaches as a strategy to advance our understanding of health and disease. Genome Medicine, 1(35).



a The Institute for Functional Medicine (IFM) (2008) Vision/Strategic Plan. [Online]. Available at: [Accessed: 11 January 2014].


b The Institute for Functional Medicine (IFM) (2008) The Movement – Functional Medicine in Clinical Practice. [Online]. Available at: [Accessed: 10 January 2014].


c The Institute for Functional Medicine (IFM) (2008) What is Functional Medicine? [Online]. Available at: [Accessed: 10 December 2013].



Thomas, L.E. (2013) How evidence-based medicine biases physicians against nutrition. Medical hypotheses, 81(6), p.1116-1119.


University of West London (UWL) (2013) Unit 3 Psychoneuroimmunology. [Online]. Available at: [Accessed: 11 December 2013].


University of West London (UWL) (2013) Unit 4 Emergence of Nutritional Therapy as an Evidence Based Practice. [Online]. Available at: 4_Emergence of NT as Evidence Based Practice(1).pdf [Accessed: 11 December 2013].


World Health Organization (2014) Chronic Diseases [Online]. Available at:[Accessed: 10 January 2014).


Wong, J. (2003) Dr. Alexander Fleming and the discovery of penicillin. Primary Care Update for OB/GYNS, 10(3), p.124-126.