The Effect of 3‐Month Ingestion ofGinkgo bilobaExtract on Pancreatic β‐Cell Function in Response to Glucose Loading in Normal Glucose Tolerant Individuals

Ginkgo bilobaextract is ingested on a chronic basis for enhancing mental focus and improving cognitive function in the elderly. This study was undertaken to determine the effect ofGinkgo bilobaextract on glucose‐stimulated pancreatic β‐cell function in normal glucose‐tolerant individuals. Twenty individuals (14 females and 6 males, ages 21–57 years) underwent a 2‐hour 75 g oral glucose tolerance test (OGTT) before and after ingestion ofGinkgo bilobaextract (120 mg/day at bedtime) for 3 months. Ginkgo bilobaextract ingestion caused a decrease in systolic blood pressure from 125 ± 15 to 118 ± 12 mmHg (p <0.05) and in diastolic blood pressure from 86 ± 10 to 68 ± 10 (p <0.01). Fasting plasma insulin and C‐peptide were increased, and the insulin and C‐peptide areas under the curve during the OGTT changed from 136 ±55 to 162 ± 94 μU/ml/h (p =0.1232) and 9.67 ± 5.34 to 16.88 ± 5.20 ng/ml/h (p <0.001), respectively. The observed dissimilar insulin/C‐peptide response curves may be due toGinkgo biloba‐induced increase of the rate of insulin metabolic clearance.