Only in recent years have scientists begun to study the actual blood sugar responses to hundreds of different foods in real people, healthy people and people with diabetes. They gave them real foods—not solutions of sugars and starches in water. They measured the blood sugar levels at frequent intervals, for as long as two to three hours after the meal. To compare foods according to their true physiological effect on blood sugar levels, they came up with the term ‘glycaemic index’.

The glycaemic index (or G.I. factor as we have called it) is a ranking of foods from 0 to 100 that tells us whether a food will raise blood sugar levels dramatically, moderately, or just a little.

This research has turned some widely held beliefs upside down.

The first surprise was that many starchy foods (bread, potatoes and many types of rice) are digested and absorbed very quickly, not slowly as had always been assumed.

Secondly, they found that moderate amounts of most sugary foods (confectionery, ice cream etc.) did not produce dramatic rises in blood sugar as had always been thought. The truth was that foods containing sugar actually showed quite low-to-moderate blood sugar responses, lower than foods like bread.

So, it is time to forget the old distinctions that were made between starchy foods and sugary foods or simple versus complex carbohydrate. These distinctions are based on chemical analysis of the food, which does not reflect the effects of these foods in the body. The G.I. factor takes us nearer to a full understanding of how the body responds to carbohydrate foods.

The G.I. factor is a ranking of foods based on their overall effects on blood sugar levels. Blood sugar or blood glucose? Blood sugar and blood glucose mean the same thing, although the latter is technically more correct However, we use the term blood sugar in this book because It is more widely understood. ‘Glycaemic’ refers to ‘blood sugar’.

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Islet cells can be obtained from the pancreas of fetuses obtained in abortion, or new-born babies who die soon after birth. It has been hoped that these islet cells, which can be cultured in the laboratory, can be placed in the body of persons with diabetes and grow there to produce enough insulin to control the diabetes.

So far work in this field has been somewhat discouraging, though there is some encouragement in that the system works well in experimental animals. It is not known yet whether in the human the islet cells could grow in number and function normally after transplantation.

Tissue rejection remains a problem with islet cells as with transplantation of the whole or part of the pancreas. It is likely that this problem of tissue rejection will be solved eventually. Tissue rejection refers to the process in which the body fights against strange and foreign tissues placed in the body, and thus rejects the transplant which can no longer survive.

The major problems may prove to be in the supply of islet cells and whether they can function properly when they are transplanted. There are problems in obtaining pancreas tissue from aborted fetuses – problems that are moral, ethical and practical – and these problems have not been resolved. It is not known whether islet cells will grow and function adequately when placed in a person with diabetes or whether they themselves may be damaged in the same way as the person’s own pancreas cells were damaged when he developed diabetes.

These questions are the subject of a great deal of active research in several world centers including in Australia. It may be many years before they are answered but the possibilities are very hopeful.

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