Following an application from Tchibo GmbH, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of Germany, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific substantiation of a health claim related to coffee C21 and reduction of DNA damage by decreasing spontaneous DNA strand breaks. The scope of the application was proposed to fall under a health claim based on newly developed scientific evidence. Coffee C21, a coffee standardised by its content of caffeoylquinic acids, trigonelline and N-methylpyridinium (NMP), which is the subject of the health claim, is sufficiently characterised. Reduction of DNA damage by decreasing spontaneous DNA strand breaks is a beneficial physiological effect. In weighing the evidence, the Panel took into account that one human intervention study showed that daily consumption of coffee C21 (750 ml/day) for four weeks decreased spontaneous DNA strand breaks in habitual coffee drinkers after coffee withdrawal over the previous four weeks, but that no other human studies in which these results have been replicated were provided, and that no evidence was provided for a mechanism by which coffee (including coffee C21) could exert the claimed effect. The Panel concludes that a cause and effect relationship has not been established between the consumption of coffee C21, a coffee standardised by its content of caffeoylquinic acids, trigonelline and NMP, and a reduction of DNA damage by decreasing spontaneous DNA strand breaks.