Potential mechanisms of diet therapy for fibrocystic breast conditions show inadequate evidence of effectiveness

Fibrocystic breast conditions, formerly referred to as fibrocystic breast d isease, affect about half of all women and typically present as any combina tion of breast nodularity, swelling, and pain. We reviewed the literature t o evaluate evidence supporting nutrition interventions commonly recommended for fibrocystic breast conditions by health care providers. Randomized, co ntrolled studies of the effectiveness of caffeine restriction fail to suppo rt any benefit in fibrocystic breast conditions. Similarly, evidence suppor ting evening primrose oil, vitamin E, or pyridoxine as treatments for the d iscomforts of fibrocystic breast conditions is insufficient to draw conclus ions about effectiveness. Dietary alterations that influence the intermedia te markers for fibrocystic breast conditions include low-fat (15% to 20% en ergy), high-fiber (30 g/day), and soy isoflavone regimens. However, our fin dings provide no solid evidence for secondary prevention or treatment of fi brocystic breast conditions through a dietary approach. Health care providers should limit recommendations to proven diet therapies supported by randomized, placebo-controlled trials, given the instability inherent in fibrocystic breast conditions and the near 20% placebo effect a ssociated with intervention. Because excessive estrogen or altered sensitiv ity to estrogen is the dominant theory of etiology, interventions that may modulate endogenous steroid hormones warrant further investigation as poten tial treatments for symptomatic fibrocystic breast conditions.