Health benefits
What evidence supports the strength of the effect of antioxidants in roasted coffee?
Coffee
According to Cancer Research UK, the results of the large-scale study published in 2012 clarified the evidence of the effect of coffee drinking on cancer, and that evidence beforehand had been conflicting. They say the study showed that drinking coffee "had no effect on the risk of dying from cancer. "Other studies suggest coffee consumption reduces the risk of Alzheimer's disease, dementia, Parkinson's disease, heart disease, diabetes mellitus type 2, non-alcoholic fatty liver disease, cirrhosis, and gout. The fact that decaffeinated coffee also exhibits preventative effects against diseases such as prostate cancer and type 2 diabetes suggests that coffee's health benefits are not solely a product of its caffeine content. Specifically, the antidiabetic effect of caffeine has been attributed to caffeic acid and chlorogenic acid. The presence of antioxidants in coffee has been shown to prevent free radicals from causing cell damage. Evidence suggests that roasted coffee has a stronger antioxidant effect than green coffee. Coffee is no longer thought to be a risk factor for coronary heart disease. A 2012 meta-analysis concluded that people who drank moderate amounts of coffee had a lower rate of heart failure, with the biggest effect found for those who drank more than four cups a day. Moreover, habitual coffee consumption is associated with improved vascular function. In a ten year study among 50,739 US women (mean age, 63 years) free of depressive symptoms at baseline (in 1996), coffee consumption was negatively correlated with risk of developing depression. A review published in 2004 indicated a negative correlation between suicide rates and coffee consumption. It was suggested that the action of caffeine in blocking the inhibitory effects of adenosine on dopamine nerves in the brain reduced feelings of depression. Coffee consumption is also associated with improved endothelial function. Coffee extracts have been shown to inhibit 11beta-hydroxysteroid dehydrogenase type 1, enzyme which converts cortisone to cortisol and is a current pharmaceutical target for the treatment of diabetes type 2 and the metabolic syndrome.