Inconsistency between glycemic and insulinemic responses to regular and fermented milk products

\Background: Foods with a low glycemic index are increasingly being acknowl edged as beneficial in relation to the insulin resistance syndrome. Certain organic acids can lower the glycemic index of bread products. However, the possible effect of acids in fermented milk products on the glycemic index and on insulinemic characteristics has not been addressed. The metabolic ef fects of fermented milk or pickled products used as additives to mixed meal s have also not been addressed. Objectives: One objective was to characterize the glycemic and insulinemic responses after intake of regular or fermented milk products (study 1). In addition, the acute metabolic effect of fermented milk (yogurt) and pickled cucumber as supplements to a traditional breakfast based on a high-glycemi c index bread:was evaluated (study 2). Design: Ten healthy volunteers were served different breakfast meals after an overnight fast. Capillary blood samples were collected before and during 2 (study 1) or 3 (study 2) h after the meal. White-wheat bread was used as a reference meal in both studies. Results: The lactic acid in the fermented mirk products did not lower the g lycemic and insulinemic indexes. Despite low glycemic indexes of 15-30, all of the milk products produced hi h insulinemic indexes of 90-98, which wer e not significantly different from the insulinemic index of the reference b read. Addition of fermented milk (yogurt) and pickled cucumber to a breakfa st with a high-glycemic index bread significantly lowered postprandial glyc emia and insulinemia compared with the reference meal. In contrast, additio n of regular milk and fresh cucumber had no favorable effect on the metabol ic responses. Conclusions: Milk products appear insulinotropic as judged from 3-fold to 6 -fold higher insulinemic indexes than expected from the corresponding glyce mic indexes. The presence of organic acids may counteract the insulinotropi c effect of milk in mixed meals.