DISEASE CHARACTERISTICS:

• Bothersome hot flashes, defined by their occurrence ≥ 28 times per week and of sufficient severity to make the patient desire therapeutic intervention

  • Presence of hot flashes for ≥ 1 month

• Meets 1 of the following criteria:

  • History of breast cancer or other cancer (currently without malignant disease)
  • No history of breast cancer and wishes to avoid estrogen due to a perceived increased risk of breast cancer
• Hormone receptor status not specified

PATIENT CHARACTERISTICS:

• Postmenopausal as defined by 1 of the following*:

  • Absence of a period in the past 12 months
  • Bilateral oophorectomy
• NOTE: *Women with ≥ 1 ovary but without a uterus should be deemed postmenopausal by either age > 55 OR a combination of estrogen within a postmenopausal range (per local lab) and follicle-stimulating hormone > 40 mIU/mL
• ECOG performance status 0-1
• Life expectancy ≥ 6 months
• Able to complete questionnaire(s) alone or with assistance
• No diabetes requiring oral or injectable antihyperglycemics
• No hypotension
• No history of allergic or other adverse reaction to flaxseed
• No irritable bowel syndrome, colitis, Crohn disease, or any gastrointestinal condition where the patient should not consume and/or has an intolerance/allergies to seeds or nuts

PRIOR CONCURRENT THERAPY:

• At least 4 weeks since prior and no concurrent or planned androgens, estrogens, or progestational agents

  • Tamoxifen, raloxifene, or aromatase inhibitors are allowed provided the patient has been on a constant dose for ≥ 4 weeks and is not expected to stop the medication during study treatment

• At least 4 weeks since prior and no concurrent anti-cancer therapies of any kind

  • Trastuzumab allowed
• No concurrent treatment with other anti-cancer therapies of any kind except for trastuzumab or endocrine therapies

• No concurrent (≤ 7 days prior to registration) or planned use of other agents for treating hot flashes (i.e., gabapentin, clonidine, antidepressants, estrogen treatment, megestrol acetate, or Bellergal)

  • Stable dose of vitamin E (as a general vitamin supplement) allowed provided it is ≤ 800 IU/day, it was started > 30 days before study initiation, and is to be continued through study period
  • Patients who have been using antidepressants for mood and have been on a stable dose for over a month and meet the eligibility criteria for hot flash frequency and duration are eligible

• No concurrent anticoagulants or anti-platelets (1 mg of coumadin for central line patency allowed)

  • Aspirin allowed (≤ 81 mg)
• No concurrent anti-hypertensives
• No other concurrent herbal supplements for any reason, including soy and soy supplements (i.e., powders, pills, or milk)