Enduring myth about diabetes

In the last three presentations I have given in Adelaide, Perth and Brisbane I have been thrown the question “Doesn’t sugar in the diet cause diabetes?” Maybe it was coincidence, but I thought I would give you a quick answer.

It was believed that sugar caused diabetes about 100 years ago. When Canadians Dr Frederick Banting and graduate student Charles Best isolated insulin and gave the first injection to Len Thompson on 11 January 1922, the research world took a whole new view of the cause and treatment of diabetes. It was quickly realised that sugar in the diet was not involved in either type 1 (requiring insulin injections) or type 2 (usually requiring a better diet and exercise) diabetes.

Type 1 diabetes in young people is likely due to a viral infection that affects insulin-producing cells in the pancreas. Type 2 diabetes, in most cases, is caused by too much food and too little exercise making the cells in the body less sensitive to the insulin from the pancreas. A lifestyle disease, as they say.

The bottom line is that, although it sounds logical, excess sugar in the blood hasn’t got anything to do with sugar in food (just as cholesterol in food has little to do with cholesterol in blood, another confusing physiology story for a later date).