European Coffee Federation: Nuance needed for diuretic effect

European Coffee Federation director Tijmen de Vries said: “The statement that ‘it is well established that caffeine has a diuretic effect’ is misleading in its conciseness and would benefit from adding nuance.”​

He referenced one study conducted by an employee of PepsiCo that came in after the opinion’s cut off point, which found no significant differences in total body water​ or any of the blood measures of hydration status between those who drank coffee compared to water.

Other research not assessed by EFSA suggested genetic variations in the sleep effects of caffeine as well as a review that suggested caffeine intakes of 2.5 mg per kg body weight may be okay for children aged four and over.

de Vries said the opinion contained some contradictions, referencing the 2011 health claim opinion on reduced perceived exertion as a beneficial effect at one point and potentially adverse later.

EFSA responded to him and others that it was impossible to include all research but welcomed the suggested reading. The agency also said that it was possible for a foodstuff to have both an adverse and beneficial effect, depending on the context.