The contribution of soy consumption to three current major world epidemic diseases.

Abstract

With the current worldwide health problems of an epidemic of obesity identified by the WHO in 1997 as a disease running parallel with other major diseases that are causing untold suffering both amongst the very young with childhood blood cancer leukaemia and an increasing epidemic amongst the elderly with Alzheimer's Dementia disease. The problem for many authorities is both cause and possible solutions. Most explanations as to why obesity occurs remain unsatisfactory. While medical science has improved the survival rates for childhood leukaemia cancer, it so far, has not provided sufficient explanation, as to why, the high incidence of child leukaemia continues to occur despite medical advances. The burden of Alzheimer's disease is also reaching epidemic proportions across the Western world as well as other countries, such that, the spiralling economic cost of care alone is now calculated in the billions, and which, if it continues may possibly cripple the, economy of some countries. The question remains, why, in this modern day and age with all the advances of science and understanding of medical science these three apparently disparate areas of human affliction continue to increase across many populations. Currently there are no plausible answers forthcoming for the proliferation of these diseases. In relation to obesity, many still regard it merely a matter of eating too much and exercising too little. For child leukaemia especially those born leukaemic, it is tenuous to correlate the disease with lifestyle factors. For those who develop Alzheimer’s Disease, lifestyle over a lifetime could certainly have a part to play, but what, when other individuals with similar lifestyles do not develop the disease? The simplest common factor explaining the onset of these three afflictions is diet. The question arises as to what kinds of dietary changes are now in place or what type of food changes are being invoked and consumed, in sufficient quantities, and that are perhaps markedly different from previous generations. The food supply of the majority of humans in the 21st century contains large amounts of industrially processed products. These new, and abundant, dietary components may contain, and have, unexpected consequences and effects contributing to obesity, child leukaemia and Alzheimer's disease. The one foremost food ingredient besides sugar, that seems to dominate the food supply is soybean. Industrially processed soybean products are now ubiquitous in the food supply of many nations. Unlike traditional Asian soy derived foods, western style industrially processed soy products (soybean oil, soy flour, soy milk, soy lecithin, tofu and an extensive array of soy utilizing processed packaged foods), are not subject to fermentation. Fermentation reduces anti-nutrient and phytohormonal contents of soy although not completely. It is well recognized that modern soy products block absorption of essential minerals (e.g. iodine) and that they contain large amounts of (e.g. genistein). Although soy is promoted as a source of cheap protein, that is supposed to improve human diets, its anti-nutrient and xenoestrogen component content, may in actual fact, produce more detrimental effects for the human body, than the so far perceived and commercially promoted “benefits” derived from increased consumption of readily and cheaply available soy protein. The capacity of soy to not only lower iodine intake besides other essential minerals and nutrients, also, introduces into the human body, a number of extraneous estrogen like substances which may slow down metabolism sufficiently and promote female pattern of fat deposition. Hence, their hypothesized link to obesity in the first instance. Genistein is also known to be a topoisomerase type II poison, and could well be a contributing factor to interference of cellular development, causing DNA disruption and creating chromosomal aberrations in the rapidly developing embryo, during the vulnerable prenatal stages, especially, where the mother is ingesting soy products as part of her diet. And similarly therefore, the hypothesis linking soy to childhood leukaemia. Furthermore, genistein, despite some short term studies not only disrupts thyroid function, with its interaction with the hippocampus, pituitary and thyroid axis may also possibly be a slow, contributing factor, to the early stages of memory loss as well as impaired motor coordination as frequently observed in Alzheimer's symptoms. The meta-analysis of soy consumption and these three major diseases with prevalence across all countries for which WHO information is available, presented in this thesis, is the first in the literature tabulating an empirical result supporting the hypothesis that industrially processed soy products may contribute to the worldwide increase of overweight and obesity, childhood leukaemia and Alzheimer's disease. Of special interest are the results showing greater prevalence of obesity and poor, but heavily soybean exposed, Latin American countries than in wealthy, but using little soy, countries of the European Union. The results also show, that the two nations with the highest consumption of soy per capita, are also the two nations with the highest incidence of child leukaemia, and also the highest incidence of Alzheimer's disease (China and USA) besides their problems with an epidemic of obesity. These empirical findings indicate the need for the implementation of public health measures, to counter the increasing obesity and Alzheimer’s epidemics, the continued high incidence of childhood leukaemia despite improved medical survival rates. At policy level it may have to be decided to weigh up the economic-political benefits as opposed to the economic drain due to the escalating high cost and maintenance of medical care for all these diseases. On a broader scale, this thesis also argues that the food industry needs to be more thoroughly scrutinised to prevent its profit seeking business model and/or behaviour from creating worldwide public health problems.