Methylxanthines and fibrocystic breast disease: a study of correlations.

Daily methylxanthine ingestion from drug and dietary sources was studied by means of questionnaires from a sample of 102 women who visited the office of a radiologist for xeromammograms. The mammograms were used to measure the level of fibrocystic breast disease. Fibrocystic breast disease was found to be positively correlated with both caffeine and total methylxanthine ingestion. These positive findings are discussed in light of the fact that most recent studies of this link have been negative.