Coffee and flow-mediated dilation

• In two small experiments, with 15 and 20 participants respectively,researchers tested for effects of decaffeinated and caffeinated espresso coffee on the flow-mediated dilation in the brachial artery^30,31. They tested for a very short-term effect, up to 60 minutes after consumption. They observed a 22% reduction of the flow-mediated dilation after consumption of a cup of caffeinated espresso. After the decaffeinated espresso, there was indication of an opposite effect, but this did not reach statistical significance

• A further small study published in 2016 compared flow-mediated dilation in caffeine consumers to caffeine abstainers, concluding that after 8 weeks no significant difference on flow mediated dilation between the groups was observed³²

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