Tics affect 4% to 24% of children and are not always clearly related to a specific condition. In a case study of two related children, caffeine intake was associated with facial and neck muscle tics. Investigators noticed a correlation between children's tics and their consumption of 2 to 4 daily servings of caffeine beverages and multiple servings of chocolate. When the children eliminated caffeine from their diet for 6 months, their tics stopped. When they tried caffeine again, the tics returned. The children avoided caffeine for 2 years, and when they tried it again his tics returned again.
Pediatrics electronic pages 1998;101(6):e4.
COMMENT: Another reason to avoid coffee. One should wonder what additional subtle biochemical complications that one can not readily observe that are also occurring when consuming foods we were not designed to eat.