And, indeed, the statistics are frightening. There are now an estimated two-and-a-half million diabetics in the UK and nearly 20 million in the US - roughly 8 per cent of the population. At the current rate of increase, those numbers are expected to double by 2010 (Br J Commun Nurs, 2002; 7: 414-9).

A ‘Cinderella disease’ for decades, diabetes is finally becoming recognised as a major health problem. 'Diabetes could become the AIDS of the 21st century,' says Professor George Alberti, president of the International Diabetes Federation.

Diabetes used to be a disease of middle-age, but now, adolescents and even children are succumbing to it. In 1982, about 4 per cent of children in the US had diabetes but, by 1994, that figure had risen to a staggering 16 per cent. Similarly, in Britain, childhood diabetes has been increasing by 4 per cent a year since 1984 - with a staggering 11 per cent annual increase in the under-fives (BMJ, 1997; 315: 713-7).

Such a situation has been described as 'potentially devastating' because children with diabetes are doomed to die prematurely from heart disease or stroke - just two of the many diseases that diabetes brings in its wake.

Once a rarity in the underdeveloped countries, diabetes is on the rise in these countries too, as they begin to adopt the Western lifestyle. This was first seen in Japan after World War II, then in Korea, Taiwan, Southeast Asia, and now Mexico and the more affluent parts of North Africa (Publ Health Nutr, 2002; 5: 141-8). The generally accepted explanation is the increased food intake coupled with a more sedentary lifestyle.

That diabetes is a ‘disease of civilisation’ has been acknowledged almost since the condition was first identified. For years, obesity has been thought to be the primary risk factor because 90 per cent of diabetics are seriously overweight.

But there’s increasing evidence that this picture is incomplete. New research suggests that the obesity-diabetes connection is too simplistic. In fact, a major rethink of the whole diabetes picture is now taking place as previously unrecognised causes of the disease are beginning to be uncovered.

What is diabetes? Diabetes is basically a disorder of the bodily system that regulates the amount of glucose in the bloodstream. Glucose is the body’s chief source of energy, and is manufactured by metabolising carbohydrates in the diet.

Despite wide variations in carbohydrate intake, the body manages to maintain glucose levels at a constant 1 gram/litre of blood. The organ responsible for this marvel of regulation is the pancreas. If blood glucose levels are too low, the pancreas makes a chemical called glucagon, which releases stored glucose. In contrast, if blood glucose levels are too high, the pancreas releases insulin, which removes the excess glucose from the blood and stores it in the muscles, liver or fat cells.

Any dysfunction in the insulin- glucose regulatory system will cause diabetes. One type of malfunction is the result of damage to the insulin-producing cells in the pancreas, leading to a dramatically reduced supply of insulin. This is called type 1 diabetes, the severe form of the disease that mainly strikes children and young adults.

The cause of type 1 diabetes is largely mysterious, but it often occurs after a viral infection, particularly of the intestines. Enteric viruses have therefore been suggested as a possible cause of damage to the insulin-producing cells of the pancreas (Clin Diag Virol, 1998; 9: 77-84). Type 1 diabetics must receive artificial insulin or they will go into a glucose-induced coma and die.