12 January - 20 June 2016

Coffee high in chlorogenic acids may improve endothelial function

Coffee consumed worldwide contains ample amounts of polyphenols. The beverage has been associated with lower risk of metabolic syndrome, diabetes and coronary heart disease. However there have been mixed results regarding coffee drinking and risk of cardiovascular disease. A study published in the European Journal of Nutrition notes that “one possible reason for the different results of studies is that the content of chlorogenic acids which are the most abundant antioxidants in coffee may vary depending on several factors.”

Coffee consumed worldwide contains ample amounts of polyphenols.  The beverage has been associated with lower risk of metabolic syndrome, diabetes and coronary heart disease.  However there have been mixed results regarding coffee drinking and risk of cardiovascular disease. A study published in the European Journal of Nutrition notes that “one possible reason for the different results of studies is that the content of chlorogenic acids which are the most abundant antioxidants in coffee may vary depending on several factors.”  The scientists of this current study therefore decided to investigate the effect of coffee with a high content of chlorogenic acids and different contents of hydroxyhydroquinone on endothelial function. Endothelial dysfunction has been found to have an “independent predictor” of cardiovascular events. 

Higashi et al. recruited 37 participants, aged 30 years or older with borderline or stage 1 hypertension. The participants were split into two study groups.  In the first study the participants consumed a test meal with either a beverage (beverage A - roasted coffee with hydroxyhydroquinone removed) containing 412 mg chlorogenic acids, 0.11 mg hydroxyhydroquinone, and 69 mg caffeine or a test meal with a beverage (beverage B - ordinary brewed coffee) containing 373 mg chlorogenic acids, 0.76 mg hydroxyhydroquinone, and 75 mg caffeine.  Higashi et al note that “Direct measurements of commercially available brewed coffee showed that less than 200 mg chlorogenic acids is generally contained in one serving.” After a 7 day wash out period the participants consumed the alternative beverage and test meal.  The participants fasted for 12 hours prior to consuming the meal.  Blood samples were taken and flow mediated vasodilation (FMD) used to evaluate endothelial function measured at 1 and 2 hours after ingestion. 

The scientists found that compared to baseline, at 1 hr and 2 hrs after ingestion of the beverages, there was an increase in triglyceride,  glucose, insulin and chlorogenic acid.  With beverage A increasing FMD by 20% at 1 hr and 33% at 2 hrs.  No difference in FMD was observed after drinking beverage B.  The study notes that “there were no significant difference in other postprandial parameters between beverage A and beverage B”. 

In the second study, the participants consumed a test meal but this time with either beverage A or beverage C (placebo) containing 0 mg chlorogenic acids, 0.1 mg hydroxyhydroquinone and 59 mg caffeine. Again after a 7 day wash out period the participants consumed the alternative beverage and test meal. In this study the chlorogenic acid concentration were significantly higher in the participants blood after ingestion of beverage A than beverage C.  Beverage A increased FMD by 58% at 1 hr and by 48% after 2 hours whilst beverage C results were no different from that at baseline. 

Higashi et al report that their finding showed that a “single intake of coffee with a high content of chlorogenic acids and high content of hydroxyhydroquinone or placebo coffee, significantly improved postprandial endothelial dysfunction.”  The authors discuss a number of limitations including that this was a small study, and that long term interventions are needed “to determine whether acute effects of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone are sustained over time.” They also note that coffee contains “hundreds of compounds that might affect endothelial function” and report that other compounds other than chlorogenic acids and hydroxyhydroquinone may have a greater influence.   

share this article
RSSL endeavours to check the veracity of news stories cited in this free e-mail bulletin by referring to the primary source, but cannot be held responsible for inaccuracies in the articles so published. RSSL provides links to other World Wide Web sites as a convenience to users, but cannot be held responsible for the content or availability of these sites. This document may be copied and distributed provided the source is cited as RSSL's Food e-News and the information so distributed is not used for profit.

Previous editions

Load more editions

Make an Enquiry