A new review claims that a diet rich in carbohydrates may help improve insulin control, giving more support to FAO/WHO recommendations for a high-carbohydrate diet with low GI foods.
The review aims to clarify current scientific knowledge of dietary carbohydrate intake and insulin resistance, giving a much needed 'progress report' on the state of current nutrition research.
Modern dietary advice to reduce the risk of diabetes is to avoid simple carbohydrates and sugars and to eat starch and complex carbohydrates.
"However, this approach assumes that simple sugars are digested and absorbed more quickly and does not take into account metabolic evidence that many starchy foods can produce even higher glycaemic responses than simple sugars," wrote author Dr Neville McClenaghan from the University of Ulster.
Insulin resistance occurs when the body does not respond appropriately to the effects of insulin and is a precursor and feature of type 2 diabetes, the most common form of diabetes in the UK.
More than two million people suffer from diabetes in the UK, with a further million suspected as living with the disease but unaware of their condition. Diabetes care costs the British National Health Service over £5 million per year, equivalent to nine per cent of its total budget.
The review, published in Nutrition Research Reviews, pulls together numerous epidemiological and intervention studies to fully evaluate the effects of high and low carbohydrate diets on blood sugar control in people with and without diabtetes.
"Collectively, the data described in the present paper support the view that high-carbohydrate diets do not adversely affect insulin sensitivity, and may offer some beneficial effects," said McClenaghan.
The review also appears to support the method of ranking foods by their glycaemic index (GI). The system has been slow to gain public acceptance due to its complexity.
But McClenaghan warned, "GI values cannot be used in isolation and nutrient composition of the foods and overall dietary pattern are also important."
"Although an increasing body of evidence would suggest merit in adopting high-carbohydrate, low-GI diets, the charge that high-GI diets result in insulin resistance is unproven on the basis of current experimental data," he said.
This view echoes recent claims by Dr. Glenn Gaesser from the US Grain Foods Foundation.
"The utility of the glycaemic index and glycaemic load (GL) with regard to health and weight control is overstated and not backed by a fair amount of published research," he said.
While the debate about the validity of GI rumbles on, it is widely accepted that a high-fat, low-carbohydrate diet is associated with insulin resistance and diabetes development.