Dietary supplementation with decaffeinated green coffee improves diet-induced insulin resistance and brain energy metabolism in mice

Objectives: There is accumulating evidence that coffee consumption may reduce risk for type 2 diabetes, a known risk factor for Alzheimer's and other neurological diseases. Coffee consumption is also associated with reduced risk for Alzheimer's disease and non-Alzheimer's dementias. However, preventive and therapeutic development of coffee is complicated by the cardiovascular side effects of caffeine intake. As coffee is also a rich source of chlorogenic acids and many bioactive compounds other than caffeine, we hypothesized that decaffeinated coffee drinks may exert beneficial effects on the brain. Methods: We have investigated whether dietary supplementation with a standardized decaffeinated green coffee preparation, Svetol®, might modulate diet-induced insulin resistance and brain energy metabolism dysfunction in a high-fat diet mouse model. Results: As expected, dietary supplementation with Svetol® significantly attenuated the development of highfat diet-induced deficits in glucose-tolerance response. We have also found that Svetol® treatment improved brain mitochondrial energy metabolism as determined by oxygen consumption rate. Consistent with this evidence, follow-up gene expression profiling with Agilent whole-genome microarray revealed that the decaffeinated coffee treatment modulated a number of genes in the brain that are implicated in cellular energy metabolism. Discussion: Our evidence is the first demonstration that dietary supplementation with a decaffeinated green coffee preparationmay beneficially influence the brain, in particular promoting brain energy metabolic processes.