Postprandial glucose and insulin responses to onion ingestion with breakfast in patients with type 2 diabetes

Several studies on animals reveal that some plants like onion can change serum glucose and insulin level. Thus, this study was performed to find out the effect of onion ingestion with breakfast on postprandial glucose and insulin responses in type 2 diabetic patients. This quasi-experimental research was performed on 26 patients with type 2 diabetes who were referred to Iranian Diabetic Association in 2 different days (1 week interval). In each day of the study, 2 ml fasting blood sample was collected in the morning from each patient and then the patients received their breakfasts. In the second day, patients had the same breakfast plus 60 grams of onion. Blood samples were collected at 60, 120 and 180 minutes after the having the breakfasts in both days. Eventually serum glucose and insulin were measured in the taken blood samples. Data were analyzed with SPSS v.13 and nutritionist IV software and were assessed using the Repeated-measures analysis of variance and paired t-test. The average age of the patients was 49.4±7.4 and mean duration of the disease was 6.9±5.05 years. Effect of onion breakfast on glucose level was not significant (P>0.05), whereas serum insulin level was increased significantly (P<0.001). Significant differences were detected in the area under the curve of glucose between first day and second day (P<0.05). Daily onion ingestion with breakfast may have beneficial effect on glycemic control in type 2 diabetic patients.