High GI foods linked to greater risk of type 2 diabetes

Men and women with the highest quartile of white bread intake were 37 per cent more likely to develop the disease than those with lowest intake, showed results from the prospective study.

It also revealed that intakes of carbohydrate, sugars and magnesium were inversely associated with incidence of diabetes, whereas intake of starch and dietary glycaemic index were positively associated with the disease.

The researchers from the Cancer Council Victoria and the Charles Darwin University suggest that people looking to minimize their risk of diabetes should choose foods that do not cause spikes in blood sugar levels, like fruit, vegetables and wholegrain breads.

However while this offers food makers a significant opportunity, barriers to marketing such foods remain.

The number of people in the UK with diabetes has surged to 1.8 million from 400,000 in just eight years, according to recent figures, with most of these -1.5 million - suffering from type 2 diabetes.

Low-glycaemic index foods could therefore give food makers a valuable way of addressing the rapid rise in this obesity-related disease. The new study supports a growing body of evidence demonstrating its benefits in at-risk consumers, although assessing the value to otherwise healthy people remains a challenge, not yet overcome.

There is also a need for further work to support the GI method of ranking foods before it can be widely used by consumers.

AFSSA, the French food safety authority, which last month called for a significant reduction of sugars added to processed foods, considers the glycaemic index to be too complicated and lacking in evidence to of its health benefits to be included in nutritional labelling.

But some groups are attempting to better define which foods fit into the 'low-GI' category. The American Association of Cereal Chemists (AACC)has recently approved​ the formation of a committee to develop a science-based definition of glycaemic carbohydrates.

The committee's aim is to provide a measurable definition that will enable manufacturers to communicate the glycemic response in grams per serving of food. This information will hopefully help consumers better understand how the carbohydrate content of a given food will affect blood sugar levels.

Until then, food makers can help provide the necessary scientific evidence by offering consumers a choice of low-GI products, even if they are not allowed to make claims, suggest industry observers.

The new study results, published in this month's Diabetes Care​ (27, pp 2701-2706), were gathered from data on 31,641 men and women aged 40-69 years, enrolled without diabetes, and followed-up four years later.