Effects of Red Wine and Daily Exercise on Glycemic Control in Insulin Resistant Individuals

Alcohol increases insulin secretion in response to ingested carbohydrates and exercise enhances insulin sensitivity; therefore, we tested the hypothesis that the combination of wine and exercise would enhance glycemic control in individuals with type 2 diabetes (T2D) or prediabetes. Eleven participants (8 women, 3 men; T2D n=5 [3 women, 2 men], prediabetes n=6 [5 women, 1 man]) completed four different 1-week treatment periods consisting of no alcohol and no exercise (Con), daily red wine with dinner and no exercise (Wine), no alcohol and daily exercise (60 min at 55% heart rate reserve; Ex), or daily wine with dinner and daily exercise (Ex + Wine). During the last three days of each treatment period, each participant wore a continuous glucose monitor (CGM) to record blood glucose data. Mean 24-hr glucose levels, defined as the average of all CGM values collected at 5-min intervals over 3 consecutive days in each treatment period, were 130 ± 22.7, 130 ± 20.6, 122 ± 17.5, 121 ± 24.9 mg/dl for Con, Wine, Ex, and Ex + Wine treatments, respectively. Exercise lowered mean 24-hr glucose (p = 0.017), but wine had no effect. Dinner postprandial glucose (PPG) responses were reduced by wine (p = 0.003), but not exercise, and breakfast PPG responses were unaffected by either treatment. There was no wine-exercise interaction detected for any variable. These results suggest that one week of exercise lowers mean 24-hr glucose and that wine was associated with lower evening PPG responses after a mixed meal in this group of insulin resistant individuals.