The patients will be given a form in which they registered any deviation and compliance with respect to coffee intake and appropriate telephone contacts to report immediately any side effect. To reduce the risk of any bias due to inter-individual changes in the preparation of coffee, the patients will be provided with typical Italian-style coffee machine of the stove-top type (MokaTMBialetti), the required amount of coffee for the preparation of the 4 coffee cups/day (8 g for each coffee preparation) and instructions on how to prepare it.