The relevance of nutrition to health has been known since the Enlightenment. Before industrialization and processed food manufacturers, it was commonplace for doctors to treat conditions with dietary controls or supplements. In the 1740s a naval surg

At the end of the 19th century, a Dutch doctor, Christian van Eijkman, traced the cause of the fatal disease beri-beri to a diet of polished rice.

With such discoveries, the illnesses associated with gross nutritional deficiencies were cured. As the industrial revolution and mechanized agriculture developed in the 19th century, scientists began to understand the more complex make-up of food. They identified the relationship of trace elements and minerals to human health and towards the end of the 19th century came the discovery of some of the most important elements, such as iron, copper and zinc. The first vitamins were also identified at the turn of the century.

What science was not able to do until much later in the 20th century was to describe the interaction of vitamins, minerals and other elements in their journey through the human body. The development of knowledge about nutrition has grown with the development of the technology used to assess increasingly small parts of biological material. Only in the last 10 to 15 years has the effect on human health of the more esoteric elements like vanadium, cobalt and nickel been identified.

During the 1920s and 1930s, great strides were made by science in identifying vitamins and minerals and relating these elements to human health and nutrition. During this period, a divergence became evident between the producers of industrially processed food and those who followed the scientific evaluation of nutrition. A school of nutritional medicine began to develop, but, even in the 1930s, those who followed the scientific paradigm of nutrition were isolated and their ideas ridiculed.

A number of doctors and therapists had begun to base their practice solely on the regulation of diet. Dr Max Gerson treated cancer with cleansing diets based on fruit and vegetables, from which tea, coffee, sugar and refined carbohydrates were sternly excluded. Dr Max Birchner-Benner cured patients of a variety of illnesses with a regime based on raw fruits and vegetables.

Soon after the Second World War, the food industry resumed its long courtship with the chemical industry and from the late 1950s onwards, it was downhill all the way for the British diet. The end of the war left the economy with a glut of chemicals and a wide range of new industrialized processes. With the sudden growth of the processed food industry and the greater dependence of the medical profession on pharmaceuticals, there came a divergence between those nutritionists who pursued a scientific theory of nutrition, and the food manufacturers who no longer knew nor cared about nutritional content.

By the mid-1960s in America, old ideas about wholefoods and the high- quality nutritional status of vegetables and fruits were being revitalized by the "health-food" revolution. Representatives of the chemical and pharmaceutical industries tried to ensure, however, that those who believed in the health-food concept did not link concepts of nutrition with those of disease.

What industry was trying to contain, and what it is still trying to contain, is preventative medicine; those doctors and therapists who believe in the practice of nutritional medicine lay down rules for life, not single treatments. Such rules for life have usually implied a basic antagonism with the industrial and chemical empire.

Equally, the training of orthodox doctors has consistently failed to take nutrition into account. Even when dealing with food-based problems such as allergy and intolerance, many orthodox doctors steer their way carefully through any discussion of nutrition. The idea of nutritional treatment conflicts with their training and the culture of modern medicine, which has been largely shaped by pharmaceutical interests.

Increasingly, general practitioners and MDs have been de-skilled in the healing arts. Gradually, they are losing any understanding of the biological effects of the drugs which they prescribe and the foodstuffs and chemicals which their patients consume. In a world in which doctors become detached from the basic skills of healing, issues of nutrition tend to be approached in only the crudest terms.

!AMartin J Walker