Cafestol and Kahweol Acutely Reduce Glucose Levels In Subjects With Type 2 Diabetes

Abstract

Objectives: Coffee consumption is inversely associated with the development of Type 2 Diabetes (T2D). The bioactive coffee substance cafestol has shown promising preventive effects towards T2D in cell and animal studies. The acute and combined effects of the main diterpenes in coffee, cafestol and kahweol, on glucose metabolism have not previously been investigated in subjects with T2D. Methods: In this randomized, double-blinded crossover study, 15 subjects with T2D ingested a cafestol/kahweol mixture or placebo along with a 75-g glucose load during two oral glucose tolerance tests (OGTT). Results: Results showed that the cafestol/kahweol mixture compared to placebo increased gastric inhibitory peptide (GIP) after 15-minutes by 19 pmol/l (p=0.055), and reduced glucose by 1.5 mmol/l after 60-minutes (p = 0.007). The area under the curve (AUC) for glucose after 1.5 hours appeared 4% lower after cafestol/kahweol capsule ingestion compared to placebo (p = 0.11), while the 3-hour AUC for GIP tended to be increased by 12% (p=0.16). Conclusions: This study is the first to demonstrate that a mixture of cafestol and kahweol acutely increases GIP levels and reduces blood glucose levels during an oral glucose tolerance test in subjects with T2D. Our findings suggest that cafestol and/or kahweol are potential contributors to the inverse association between coffee consumption and development of T2D. This indicates that a cafestol/kahweol mixture may be used in the prevention of T2D in the future.