Eating white bread is associated with increased risk of type 2 diabetes, according to a new Australian study.

After following the diets and health records of more than 36,000 men and women in Australia for four years, researchers say they found white bread and starchy foods were linked to diabetes.

"White bread was the food most strongly related to diabetes incidence," they write in the November issue of the journal Diabetes Care.

Results were based on food frequency questionnaires and diabetes diagnoses made during the study. Special attention was paid to the glycemic index (GI) of the foods eaten by participants.

The glycemic index measures a food's impact on blood sugar. High-GI foods like white bread, cakes, and biscuits spike blood sugar dramatically, while lower-GI carbs including most vegetables and legumes have a smaller effect.

Participants who ate the most white bread -- more than 17 slices per week -- had the highest risk of diabetes, say the researchers, who included Allison Hodge, MENVSC, of the Cancer Council in Victoria, Australia.

Eating lots of high-GI foods like white breads and white potatoes can cause weight gain, raising the risk of diabetes, say the researchers. A high-GI diet could also lead to insulin resistance (decreased ability for the body to respond to the hormone insulin), which can lead to diabetes.

On the other hand, participants who ate a lot of sugar, magnesium, and total carbohydrates had a lower risk of diabetes.

That's not a green light to guzzle sugar. The surveys included naturally sweet fruit, which may affect the body differently than added sugars found in cakes, pastries, and sweets.

All things considered, you may want to reach for whole-grain bread for your next sandwich.

"The simple change from white bread to lower-GI bread within a high carbohydrate diet could reduce the risk of diabetes," write the researchers. "Changing bread type may be a more acceptable dietary change than one requiring a whole new eating pattern."

Of course, eating too much of any food can add pounds, raising the risk of diabetes, Hodge and colleagues warn.

By Miranda Hitti, reviewed by Charlotte E. Grayson, MD

SOURCES: Hodge, A. Diabetes Care, November 2004; vol 27: pp 2701-2706. Reuters Health.