Effect of baking process on postprandial metabolic consequences: randomized trials in normal and type 2 diabetic...

To determine the impact of the form, fibre content, baking and processing on the glycaemic, insulinaemic and lipidaemic responses of different French breads.

First study: Nine healthy subjects were randomized to consume in a crossover design one of six kinds of French bread (each containing 50 g available carbohydrate): classic baguette, traditional baguette, loaf of wholemeal bread (WM-B), loaf of bread fermented with yeast or with leaven, a sandwich and a glucose challenge as reference.

The glycaemic index (GI) values ranged from 57+/-9% (mean+/-s.e.m.), for the traditional baguette, to 85+/-27% for the WM-B. No significant difference was found among the different tested bread. The insulinaemic index (II), however, of the traditional baguette and of the bread fermented with leaven were lower than the other breads (analysis of variance: P<0.01). Postprandial plasma triglycerides showed similar profiles. The traditional baguette tended to decrease postprandial free fatty acids compared to levels after the classic baguette.

The GI of the traditional baguette was lower than that of the classic baguette (n=8, venous blood: 70+/-4 vs 75+/-4, P=0.002; capillary blood: 69+/-5 vs 83+/-6, P=0.028, respectively).

Some varieties of French bread (the TB) have lower II, in healthy subjects, and lower GI, in type 2 diabetic subjects, than that of the other varieties. These results might be due to bread processing difference rather than fibre content.

Supported by grants from the National French Milling Association.