Evolutionary nutrition and optimal human health: an integrative perspective for contemporary Australia

What is optimal human nutrition? What dietary parameters offer the greatest potential for human performance and are most healing in their qualities? These questions have driven research agendas in nutrition science and medicine for decades and resulted in a plethora of research. Yet confusion and divergent ideas are endemic both in the scientific community and the general public. The scale and complexity of the modernday food environment means that most aspects of food and nutrition now demand an exceptionally high level of critical thinking (Nestle & Dixon 2004). Most of us do not have a direct understanding of how our food is produced and what we should ideally be eating. In response, Eaton (Eaton, Cordain & Lindeberg 2001; Eaton, Eaton & Konner 1997; Eaton & Konner 1985) and Cordain (2008; Cordain et al. 2000; Cordain et al. 2005), among others, have advocated adopting an evolutionary paradigm for understanding human health and optimal nutritional requirements. This approach is intuitively appealing because it utilises the most basic premise of biology, which is that living organisms function optimally when their life circumstances most closely match the conditions to which they were selected and became adapted to over the course of evolution. Contemporary 'conditions of life', including our food supply, are changing rapidly and are now markedly different from our evolutionarily tailored context. The majority of the population is disconnected from the process of hunting and gathering food, as well as the characteristics of a wild food menu. The health implications of this, specific to Australia, are examined in the present research. Furthermore, this investigation is focused on guiding interested Australians to make food choices that are more aligned with our evolutionarily adapted history. By doing so, the aim is to enable one to selectively eat like a ‘contemporary’ hunter-gatherer. The term ‘contemporary hunter-gatherer diets' does not imply a 'back to nature', or regressive agenda. Creating contemporarily relevant health advice based purely on the examination of the conditions of recent hunter-gatherer societies (often eco-romantically expressed) fails to acknowledge the forward moving process of evolution. We need to recapture this original, primal way of life because it is fundamental to our existence, and we need to incorporate it - to integrate it - into our modern world. Integral theory (Wilber 2000, 2001) provides a methodology with unparalleled depth and scope, and it is the basic skeleton of this theory that draws contemporary relevance from the historic research in this thesis. Hence, two theoretical frameworks are used to define the boundaries of the current investigation: (i) an evolutionary paradigm and (ii) Integral theory. Both theories are ‘evolutionary’ in their approach – meaning they address change or development through time. However, in this thesis an ‘evolutionary paradigm’ refers specifically to Darwinian theory and the mechanisms of natural selection and adaptation in evolutionary change. As such, the so named evolutionary paradigm has been used to estimate optimal nutritional requirements (and lifestyle patterns) based on the environment to which we are most genetically adapted. The database for this analysis was primarily derived from records of the subsistence patterns of 20th century hunter-gatherer societies and the nutritional characteristics of wild foods (Brand-Miller & Holt 1998; Cordain et al. 2000; Eaton & Konner 1985; Murdock 1967). This thesis reviews and critiques current core concepts in the field of evolutionary nutrition and argues the merit of viewing contemporary nutritional recommendations within this wider temporal context. The hypotheses underpinning the field of evolutionary nutrition have been established by only a few researchers, and modern-day interpretation is limited. Furthermore, specific consideration of the contemporary Australian context is absent in the literature. Therefore, the present investigation sought to address this situation by analysing key factors in relation to an 'optimal' benchmark based on an understanding of our biologically adapted needs, the dietary (and lifestyle) matrix of recent hunter-gatherer populations, and the nutritional properties of wild foods. These factors included: an examination of average Australian diets and health status; epidemiological associations between dietary factors and disease; characteristics of modern therapeutic diets; the lifecycle of plant and animal foods in their various modern-day production forms (including how to eat like a ‘contemporary hunter-gatherer’ from the modern food supply); an understanding of eating behaviours in Australian culture and our psychological relationship with food; and recognition of the 'parts' (e.g. macronutrient composition, micronutrient content, fatty acid balance, glycaemic index) and ‘wholes’ (overall guiding principles) that constitute 'optimal' nutrition. The scope of this comparative analysis was governed by the drive to model 'contemporary hunter-gatherer diets' (and lifestyle parameters) with the greatest degree of authenticity currently possible. This interpretive process was grounded in the cognitive matrix of Integral theory. At its most basic level, the theory’s inclusion of the personal ('I') (e.g. personal food choice behaviours), the collective ('We') (e.g. social attitudes to food and health and collective decisions pertaining to these issues) and the environment ('It') (e.g. our agricultural resource base) in the analysis of any issue profoundly enriched the research map. It provides the structure for a comprehensive examination of the inter-related factors involved in human health today and honours the importance of treating health in an increasingly inclusive, holistic and defined way. The consequential integrative synthesis of the evolutionary nutrition data in this way, and the conclusions that are relevant to contemporary Australia are unique and resonate with common sense. he core conclusion of this thesis differs somewhat to consensus thinking in the field of evolutionary nutrition. It is proposed that the inherent health advantages of huntergatherer diets and the wild food supply are not just based in the exclusion of ‘recently’ introduced agrarian and industrial food groups (i.e. dairy, cereal grains, fatty domesticated meats, and refined and processed foods), nor are they necessarily found in the replication of specific hunter-gatherer dietary characteristics (e.g. macronutrient composition, fatty acid balance). Rather, it is suggested that the full therapeutic benefits lie in a whole matrix of nutritive components found in whole foods that are grown and produced with a high index of biological authenticity (which refers to the degree to which food resembles its wild-type counterparts). This requires transparent knowledge of a food’s lifecycle and a deeper awareness of the way food and health decisions are imbedded in the modern Australian psyche. In response, a simple guiding principle for making nutrition decisions is proposed: Choose the freshest and most unrefined foods available from both plant and animal sources that are themselves optimally healthy, and consume these foods in quantities reflecting their availability in the wild. This is the central message of this thesis. As extensively analysed, this principle unanimously supports human health. The reassuring simplicity of the principle belies the extent of analysis undertaken. The value of understanding optimal human nutrition and its paramount importance for health needs little justification. Australia is in critical need of a cohesive nutritional and lifestyle intervention approach as obesity, metabolic disorders, chronic degenerative diseases, and mental health issues continue to escalate in the population and affect quality of life and longevity, as well as posing significant social costs. A key outcome of this research is the development of an illustrative model for guiding and prioritising food choices in contemporary Australia based on an evolutionary perspective. The model is designed to be relevant both to individuals interested in using food as a therapeutic tool and for clinicians across a spectrum of medical, nutritional and allied heath professions. While being cognisant of the use of predictive patterns and unconfirmed assumptions in the present research, what is outlined is viewed as being effective, efficient and of immediate clinical relevance