Key Findings:
Two slices of bread containing a total of 25g partially defatted ground flaxseed was examined for effects of the lignans on the climacteric symptoms and endometrial thickness of 38 postmenopausal patients. The control wheat bran group had significant reductions in plasma HDLC and FSH concentrations after the intervention. In contrast to many studies, flaxseed had no effect on total- and LDL-C. Both groups had significant reductions in climacteric symptoms (Kupperman Menopausal Index) and occurrences of hot flashes. The total intake of flaxseed lignans may have been too low and the duration of the study too short, to yield significant results under the experimental conditions.
ABSTRACT:
Our objective in this work was to test the effects of daily intake of bread produced with partially defatted ground flaxseed on the climacteric symptoms and endometrial thickness of postmenopausal women. A double-blind, placebo-controlled, randomized clinical trial was performed with 38 women who had been postmenopausal for 1–10 y and consumed 2 slices of bread containing 25 g of flaxseed (46 mg lignans) or wheat bran (1 mg lignans; control) every day for 12 consecutive weeks. The outcome variables were the daily number of hot flashes, the Kupperman Menopausal Index (KMI), and endometrial thickness. The plasma lipid profile (total cholesterol and HDL, LDL, and VLDL cholesterol fractions and triglycerides) and the hormones estradiol, follicle-stimulating hormone, thyroid-stimulating hormone, and free thyroxine also were measured. Food intake was evaluated by means of 2 24-h recalls, before and after the treatment. Twenty patients in the study group and 18 in the control group completed the study. The general characteristics did not differ between the 2 groups at the start of the study. Both had significant, but similar, reductions in hot flashes and KMI after 3 mo of treatment. Moreover, endometrial thickness was not affected in either group. Our findings clearly show that although flaxseed is safe, its consumption at this level (46 mg lignans/d) is no more effective than placebo for reducing hot flashes and KMI. (Author’s abstract)