Coffee consumption and fibrocystic breasts: an unlikely association.

Caffeine and other methylxanthines have recently come under scrutiny as substances that may cause breast tissue to undergo fibrocystic changes. The authors present a retrospective 5-year study of 358 women with fibrocystic breast disease and a 6-month prospective study of 72 women with this condition. Although methylxanthine consumption was constant, the clinical findings in semiannual or monthly examinations in both studies were inconsistent. On the basis of their results and a review of available studies, the authors believe there is no scientific basis for an association between the consumption of methylxanthines and the development of fibrocystic breast disease.