| Abstract: | The medical diagnostic approach to health sees it as the absence of disease which is classifiable in agreed biomedical terms in accordance with conventions like ICD (International Classification of Disease) and DSM (Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association). WHO also emphasises that wellbeing is an important health dimension. From a public health viewpoint, contributors to health and wellbeing include not only genetic and biomedical factors, but also social, occupational and environmental circumstances. Increasingly, it is recognised that, while Mendelian inheritance may predispose to certain illnesses, its understanding and relevance usually requires gene mapping and linkage, often involving SNPs or ‘single nucleotide polymorphisms’. The overwhelming determinants of health are those of personal behaviours and the environment. Gene expression itself is highly environmentally dependent on epigenetic and nutrigenomic mechanisms. Moreover, our genome is only partially eukaryotic (nuclear DNA), also comprising mitochondrial DNA (matrilineal), non-coding RNA (ncRNA) and dominantly prokaryotic (micro-organismal without nuclei) in our various microbiomes (in gut, skin, reproductive and respiratory systems). Even our eukaryotic genome is considered to have conjoint environmental endosymbiotic origins as advanced by Lyn Margulis. Not only are environmental determinants of this diverse genome likely to be underestimated, but it constitutes a continuum between us and our prevailing ecosystem past and present. From these considerations alone, we would expect that to optimise our health we would need to be attentive to our environmental connections. This is of ancestral interest, and of relevance to biological rhythms as well, most obviously with diurnal, lunar monthly and seasonal phenomena. Even more fundamentally, we now know fairly reliably from where in the cosmos most of the elements in the periodic table come that are found in living creatures, making us cosmological. Our moment-to-moment physiology is ecological. The minimal requirement for movement, usually by walking, is to get out of bed, fetch our food and meet others for one reason or another, taking 30–40 minutes per day (1). Indeed, we know that this is about the minimum we need in the way of daily physical activity in order to have acceptable health. In the course of walking we have the opportunity to interact with nature through contact with the undergrowth and soil (rich in microorganismal life capable of transmitting information), listening to the birds, smelling the flowers, touching the leaves, feeling the breeze and, perhaps, talking with our partner and solving problems or even snacking on fresh fruits or seeds. Countless sensory inputs are experienced, for many of which there are receptors not only at the point of first contact (as with olfaction or taste), but throughout the body after assimilation. The person who does not exercise in this way may be nature-deprived with wide-ranging health implications for mental and physical health. Our biology is affected more by matrilinearity than patrilinearity through the maternal lineage of our mitochondria, the intra-uterine environment, the acquisition of a microbiome from the maternal reproductive tract, lactation, nurturing, dependence on technologies developed initially or mostly by women (food cultivation and gardening, gathering, and cooking; textiles and clothing; language and verbal communication), and by grandmaternal more than grandpaternal support when women outlive men. Nevertheless, men’s personal behaviours – eating, exercising, smoking, drinking and having a partner – which are very much environmentally determined, matter, for not only their own health, but also their descendants. Collectively, these inputs add to our ecological characteristics. |
