Years ago, coffee had a reputation as being bad for your health. Since then, a growing body of research has been accumulating indicating that coffee may provide strong health benefits. Of course most people associate coffee with caffeine. This most well-known of coffee alkaloids is of interest to bodybuilders and other performance athletes because it  stimulates the metabolism, providing energy and enhanced body fat oxidation. It is not hard to see why so many athletes use it, and why it is so ubiquitous in fat burners, weight-loss products, pre-workouts, and energy drinks. It is effective, safe, cheap, familiar, relatively unregulated, and one of the few stimulants that is allowed by most sports federations, after the World Anti-Doping Agency (WADA) removed it from the banned list in 2004.

Aside from caffeine, however, there are many other compounds in coffee that various and sundry studies have shown to have health benefits such as reducing risk factors for type 2 diabetes, helping to regulate blood sugar, and mitigating oxidative damage to both cells and to DNA within the cells.

Add to these studies new research from Japan that indicates polyphenols in coffee may help improve endothelial function and thereby contribute to cardiovascular health with a consequent reduction in the risk of heart disease. It has been estimated that there are roughly 350 mg of polyphenols in the average American sized cup of coffee (about 300 ml).

In the Japanese study, polyphenols were extracted from green coffee beans, the caffeine removed and the extract dried and powdered. Fifteen healthy adult men consumed 75 grams of glucose with one group ingesting coffee polyphenols at the same time, and the other group receiving no polyphenols. Blood sugar levels and insulin response were the same for all subjects, but the group receiving the polyphenols registered significantly higher reactive hyperemia, a measure of increased blood flow in reaction to the increase in cellular metabolic activity.

The researchers said their findings suggest a single ingestion of coffee polyphenols improves peripheral endothelial function after glucose loading, and thus might have the potential to prevent coronary heart disease. The researchers said the specific compound for the improved endothelial function has not been identified, but chlorogenic acids were a strong candidate.

Other studies have indicated chlorogenic acids as a beneficial active ingredient in coffee, but it is concentrated in the type you can’t really drink. Green (ie: unroasted) coffee beans contain approximately 12% chlorogenic acid, but much of this is destroyed by roasting, which is essential to producing a palatable brew. For now, it appears green coffee and its extracts will be confined to supplements.


Suguira Y, Shioya Y, Ochiai R, Otsuka K, Hashiguchi T, Katsuragi Y, Kagoshima University Graduate School of Medicine and Dental Sciences, Kao Corporation Health Care Food Research Laboratories, Coffee polyphenols improve endothelial function after glucose loading in healthy male adults, Nutrition Research, doi:10.1016/j.nutres.2013.11.001

Kolb H, Herder C, Kempf, K, Erlund I, et al, Effects of coffee consumption on subclinical inflammation and other risk factors for type 2 diabetes: a clinical trial, Amercian Journal of Clinical Nutrition doi:10.3945/ajcn.2009.28548

Misik M, Hoelzl C, Cavin C, Wagner K, et al, Impact of paper filtered coffee on oxidative DNA damage: results of a clinical trial, Journal of Mutation Research, Fundamental and Molecular Mechanisms of Mutagenesis, doi:10.1016/j.mrfmmm,2010.08.003