The twentieth century has seen huge changes in the way in which we eat, what we breathe and changes in the flora in our gut. We all ate organic food before 1942, for example. The genetic makeup of homo sapiens has evolved over millions of years in environments very different to those we encounter today in our industrialised society. It is not surprising then that our ability to adapt to the changes that which have occurred in the past one hundred years has been inadequate. There have been more changes in the last century, than in the rest of recorded human history.

These changes in what we eat and breathe have been compounded by nutritional deficiencies which have occurred as a result of modern farming and food manufacturing processes. In addition, lifestyle factors such as cigarette smoking, high alcohol intake and ingestion of medical or illegal drugs, can all diminish nutritional status with a resulting reduction in an individual's ability to adapt.

A major science has developed in the past forty years, which has managed to link a large number of chronic serious illnesses to individual adverse reactions to what we eat, what we inhale and the flora of our guts. These and other conditions can also be related, partly or totally, to individual deficiencies of essential trace minerals, vitamins, essential fatty acids and amino acids.

Allergy, environmental and nutritional medicine is thus the science of cause and effect in illness. We consider the investigation of chronic illness in terms of causation to represent highly orthodox medicine. Orthodox literally means straight teaching and in medical science, straight teaching should mean that the demonstration of the basic causes of illness should be preferred to the suppression of the symptoms. There have been huge advances in determining the fundamental causes of much of human illness, and several thousand papers have been published in medical journals relating to the fields of Food Sensitivity, Chemical Sensitivity and Reactions to Gut Flora and Nutritional Medicine.

The main thrust of modern medical therapeutics is the development of novel man-made chemicals that were certainly not present during the evolution of our genes. Modern drugs are almost entirely foreign to our biological systems. In fact, if they were not novel and foreign then they would not attain a patent. As a result, several pages of contra-indications, side effects and warnings can be attached to the use of these products. In the United Kingdom, government figures show over 20,000 deaths last year as a result of an adverse reaction to prescribed drugs, and in the USA with its larger population the figure stands at 106,000. This, incidentally, contrasts interestingly with about 7,000 deaths a year at the height of the Vietnam war.

The major exception is the field of microbiology in which bacterial illnesses can usually be cured with antibiotics and viruses prevented with vaccines. The reputation of conventional medicine largely stems from the success of this particular area, which is, of course, based entirely on the concept of cause and effect.