Food Health Revolution in food fibre coming to N.Z.

Press, 5 June 1982, Page 10

Food Health Revolution in food fibre coming to N.Z.

Professor

Don Beaven

"Fibre in food." a conference just finished at Massey University was an important event. This multi-disciplinary conference was sponsored by the Royal Society of New Zealand., It took nearly three years to plan and was attended by New Zealanders, Australians, and many experts from the Northern’Hemisphere. Torrent of words During the last- decade, and stimulated by sue!, names as Denis Burkitt and Hugh Trowell - famous in their field — the bio-medical literature of the Western world has been deluged with popular and scientific articles on. fibre. Experiments using dietary changes with an increase in dietary fibre have been carried out on widely varying groups of people. Healthy subjects in England, blacks in the United Slates, heart disease patients, people with colon disorders.. and others with diabetes have all been studied and reported. So widespread and persuasive has been the writing that it has stimulated the natural food movements around the world.

These have led to changes as widespread as the introduction of Nouvelle Cuisine in France. Europe, and Australia, and to a very major dietary change in the United States' of America. The anti-meat, ' anti-fat, high natural carbohydrate changes in the United States are now believed to be the single most important reason for a reversal in death from coronary figures in North America. What is fibre? Up until the time of the industrial revolution, uppermiddle classes ate cruder foods which were in a much more natural and less processed state. Bread, for example, was hard and rough and less refined than now, It was then harder to undertake milling; and so less was extracted from the whole wheal grains. During the last century and the firsj half of this century,-.the supply of foodstuffs became more adequate for most of the Western countries of the world. Equally, there was a steady "development of food techno-

logy in the direction of refinement. What had been done in digestion and breakdown of complex foodstuffs by the .stomach and intestines for nearly 200 million years was changed in only 150 years! Now the fossil fuel reserves of two billion years of accumulated solar energy were used to reduce the “work” of the stomach.

Food was progressively made more refined, softer, and more rapidly and readily absorbed without digestion. Gradually, up to the 1950 s and 19605. we evolved a diet that became the now traditional New Zealand diet — over-fat. over-high in meat and calories, excessive sugar and energy from refined carbohydrates. Steadily the whole world is swinging away from such a diet, and the change towards a higher fibre diet is part of a world trend towards more natural ' and unprocessed foods. Fibre is the indigestible plant cell walls made of various celluloses, lignins, or woody substances in food which we think of as stalks and husks. Thus, most of the fibre in grains is in the outer part of the husk — the more refined or whiter the flour, the less the fibre content. In a cabbage or cauliflower, the more stalky parts contain more, fibre. There is more fibre in the skin and pips of a tomato, and it may be noticed that these may go through the bowel without, being absorbed.

Physiology of Fibre: Fibre is largely indigestible to humans. This may be because we have eaten less and less over the last few hundred years. Woody materials can only be digested by fermentation, as in a ruminant or animal with a specially adapted stomach. The fibre eaten by humans goes through the z stomach and intestines without being digested. This material produces greater speed through the gastro-intestinal tract with larger, softer and more frequent bowel motions. High-fibre eaters, as in Africa, may have up to three or four bowel motions daily, each three to four times larger in volume than a constipated Westerner. The rapid soft passage is thought to remove bile acids and thus prevent gallstones and some other possibly harmful substances. The fast movement of food in the small intestines, together with its more complex nature, slows down over-rapid absorption of fat and refined carbohydrates. The slower the absorption of modern refined foods, the better to prevent many disorders and diseases. More and more careful and conservative nutritionists, doctors, dietitians, and health workers are impressed by the evidence which shows that the digestive system slowly evolved over 200 million years to best use a wide variety of raw and crude plants, vegetable and animal products.

It is now clear that our preoccupation with processing and refining of food over the last 150 years has proceeded too fast for the adaptation of our physiology. Probably more than half the costs of running all our health services result from our failure to truly understand the unique adaptive ability of man to survive — but over 200 million years and not over 150 years using half the world's fossil fuels, often inappropriately!

The fibre “revolution" is, in fact, a normal swing of the pendulum towards a more rational, balanced diet of whole-grain breads, plenty of fruit, vegetables, and nuts, and a reduction of the inap-' propriately' high fat, meat, and sugar diets which des-. troy many and damage even more New Zealanders.