Before the beginning of the intervention phase, for each patient, demographical data will be collected, together with information on coffee and smoking habits, alcohol, fruit, vegetable, anti-inflammatory drugs consumption, energy and nutrients intake, as potential bias. All these data will be assessed by using a quantity-frequency questionnaire designed for use in the present study. At time 0 (T0) the patients will be categorized into two groups in relation to their routine coffee intake: 0-2 cups/day and 3-5 cups/day. This cut-off was chosen because in most papers an effect of coffee consumption is observed for over 2 cups/day.