Food Additives and Ingredients Association FAIA

WISDOM OF THE BODY

How proteins are synthesized

To renew the tissues and enzymes needed by the body, the tissues of foodstuffs have to be broken down by the body and reassambled. All proteins, in all living things on earth, are made from various combinations of just 20 Amino acids. They have to be assembled in a precise order and that order is dictated by the RNA and DNA of the genes. Each protein is coded for by a combination of 3 bases along the chain of DNA. This is the Genetic Code. To make a particular protein every amino acid in the molecule has to be available. Some foods are deficient in some amino acids and lead to deficiency diseases if the diet is not broadened to make good the missing amino acid. In this illustration the RNA code at the top is fed into the protein-making machinery in the cell (the ribosomes). RNA recognises the amino acids that corresponds to base sequence and links them together. The protein emerges, amino acid by amino acid in a linked chain which then folds up into the 3-dimensional form which allows the protein to serve its function.

NATURAL AND CHEMICAL

To be nutritious food ingredients have to have a specific function

WHY INGREDIENTS WORK

How the cook uses a battery of chemical reagents (better known by their more homely names to create familiar foods

CHEMIST IN THE KITCHEN

Chemicals have always been welcome in the kitchen: sodium bicarbonate, pectin, yeast, acetic acid etc

Food consists of nutrients held together in a form for which the body is equipped by evolution to digest. The body doesn't use food 'naturally' - it processes it ruthlessly and extracts what it needs

What we and our bodies regard as 'food' are somewhat different, and the difference is at the heart of the problem many people have with the idea of food additives. The body is in a constant turmoil of breaking down its cells and building new ones, a process know as metabolism. Its functions require energy from food, the heart pumping, the lungs extracting oxygen etc - and it requires the substances necessary to build tissue. Whole food cannot be assimilated by the body, it has to be broken down to some very basic building blocks, simple sugars like glucose, the 20 amino acids from which all proteins are made.

The body, it has to be stressed, is not interested in wholeness, quite the reverse. The only reason that the body prefers traditional solid food to a liquid diet of essential nutrients is that it has evolved as a churning machine and the gut needs bulk fibre to remain healthy. In the early days of food science some misguided visionaries believed that chemistry would one day provide all our essential nutrients, thus doing away with the need for agriculture: in 1884 the great organic chemist Marcellin Berthollet wrote a paper called 'In the year 2000'. He said:

'In the world at that time there will no longer be any agriculture or pasturage or farm laborers: the problem of existing by means of cultivating the soil will have been solved by chemistry... The day will come when everyone will carry around with him as nourishment his little nitrogen lozenge, his little pat of fats, his little piece of starch and sugar, his little flagon of aromatic spices adapted to his personal taste. 'All this will be manufactured economically and in inexhaustible quantities in our factories...Finally, all this will be free from pathogenic microbes, which are the source of epidemics and the enemies of human life....It is even possible that the sandy deserts will become the chosen sojourn of human civilisation, for they will be healthier than these infested alluvia and these marshy plains, enriched with putrefaction, which today form the agricultural scene.'

'The pendulum has swung 180 degrees since Berthollet wrote, and his distaste for messy, disease-ridden nature has been replaced by a veneration for all things natural and organic. But the baby has been thrown out with the bath water. The body's wisdom is closer to Berthollet's vision than to that of the organic lobby. It really does want its 'little nitrogen lozenge'.

The first serious use of chemistry in food was Justus von Liebig's book Organic Chemistry and its Application to Agriculture and Physiology (1840) which started to show how specific chemicals in the soil (or their absence) affected the crops grown on them, the health of the animals that browsed and, ultimately, ourselves.

Liebig was the leading organic chemist of his day and his work was widely taken up by practical agriculturists. The science of nutrition was born. Before this point everyone's diet was, by definition, organic. As a result, far from sustaining health, millions of people in Europe suffered from dietary deficiencies which could have been alleviated by specific chemicals in their diet. Goitre, rickets, scurvy were all diseases that stemmed from specific deficiencies in the diet: iodine in the case of goitre, Vitamin D in the case of rickets, and Vitamin C in the case of scurvy.