Glycemic responses to whole grain sourdough bread versus refined white bread in patients with gestational diabetes

Nutritional therapy remains a key tool for prevention and management of gestational diabetes (GDM). Carbohydrate type and absorption rate rather than the carbohydrate amount have more impact on postprandial glucose (PPG) levels in GDM. The effect of refined white bread and whole grain sourdough bread on glycemic indexes were compared in GDM patients.

A total of 43 patients with GDM and 38 healthy pregnant women were included. A similar breakfast menu was given to both groups of patients at two different times in consecutive weeks; however, different types of bread with the same weight were used for both breakfasts; 1) white wheat (WW) bread, 2) sourdough whole grain wheat (SWGW) bread. Blood glucose, insulin and C‑peptide levels were compared before and after breakfast.

Fasting glucose, insulin and c‑peptide levels were similar between groups (p > 0.05). While the second hour glucose levels were similar between the groups, the first hour results of glucose, insulin and C‑peptide levels were lower in the SWGW group (p < 0.05). In the control patients, first hour glucose, insulin and C‑peptide levels were also lower in the SWGW group (p < 0.05).

The WW bread, which is more preferred in daily life routine, causes 45.5% more insulin secretion and 9.6% more first hour postprandial blood glucose compared to SWGW bread both in GDM patients and healthy pregnant women. According to the results of this study, we recommend that sourdough whole grain bread should be preferred in order to increase the success in the management of GDM.