Dietary Flaxseed May Relieve Cyclic Mastalgia.

SAN ANTONIO -- Dietary flaxseed proved to be an effective nonpharmacologic therapy for cyclic breast pain in a double-blind, randomized clinical trial.

Eating a single daily muffin containing 25 g of ground flaxseed resulted in a significant reduction in symptoms of severe cyclic mastalgia in the 127-patient, 3-month study, Dr. Tong Li reported at a breast cancer symposium sponsored by the San Antonio Cancer Institute.

Cyclic mastalgia in premenopausal women is thought to be hormonally related. Pharmacotherapy typically involves drugs with antiestrogenic effects, including tamoxifen, danazol, and bromocriptine, but many women would prefer a nonpharmacologic alternative, as these hormonal agents are costly and have unpleasant side effects, Dr. Li commented.

Flaxseed was selected for study because it is an exceedingly rich source of mammalian lignan precursors, alpha-linoleic acid, and n-3 fatty acids. Flaxseed's likely mechanism of benefit in cyclic mastalgia involves the antiestrogenic effects of these compounds, according to Dr. Li of Princess Margaret Hospital in Toronto.

Breast pain, as assessed by patients with the aid of a visual analog scale, decreased both in the flaxseed eaters and in control subjects who consumed a daily placebo wheat-based muffin, but the reduction in pain was significantly greater in flaxseed eaters. This is a relatively mild dietary intervention, however, and flaxseed didn't become significantly more effective than placebo until after two menstrual cycles of treatment, she noted.

Symptoms of breast swelling and lumpiness in the premenopausal subjects were reduced to a comparable extent by flaxseed and placebo.

Serum levels as well as 24-hour urinary excretion of alpha-linoleic acid and total n-3 unsaturated fatty acids were significantly increased over baseline ...