Consumption of a Flaxseed-Rich Food Is Not More Effective Than a Placebo in Alleviating the Climacteric Symptoms of Postmenopausal Women 1,2
Consumption of a Flaxseed-Rich Food Is Not More Effective Than a Placebo in Alleviating the Climacteric Symptoms of Postmenopausal Women 1,2
Year: 2010
Authors: Simbalista, R.L. Sauerbronn A.V. Aldrighi J.M. Areas, J.A.G.
Publication Name: J. Nutr.
Publication Details: Volume 140; Pages 293 – 297.
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 to 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. (Authors abstract)
There is an increasing number of women with contraindications for hormonal therapy or with a preference for more natural treatments because they fear the side effects. Some epidemiological studies have shown that symptoms such as hot flashes and sweating are less prevalent and of lower intensity in Asian countries which has been associated with the consumption of phytoestrogens, such as isoflavones and lignans. Studies on isoflavones and lignans consumed in different ways have shown inconclusive results regarding effects on menopause symptoms. The main objective in this study was to test the effects of daily consumption of bread produced with partially defatted ground flaxseed that is rich in lignans on the climacteric symptoms and endometrial thickness of postmenopausal patients. The results showed that the control group had significant reductions in plasma HDLC and FSH concentrations after the intervention. Although some biological and clinical assays on flaxseed have shown its ability to reduce total- and LDL-C, this did not occur in the present intervention; these values did not vary during the study. No significant differences in symptoms between the 2 groups were noted after 12 wk of treatment. In both groups, the patients had a significant reduction in the number of hot flashes and in the KMI, in relation to the beginning of the treatment, but the groups did not differ at the end of the treatment. This improvement may be partly related to decreasing willingness to mark the symptoms correctly in the diary as time passed. The authors conclude that, in this trial, the phytoestrogens from flaxseed did not significantly affect menopausal symptoms, compared with placebo. However, this study confirms the importance of the placebo group for comparing the effects of other treatments on these symptoms. (Editors comments)
There is an increasing number of women with contraindications for hormonal therapy or with a preference for more natural treatments because they fear the side effects. Some epidemiological studies have shown that symptoms such as hot flashes and sweating are less prevalent and of lower intensity in Asian countries which has been associated with the consumption of phytoestrogens, such as isoflavones and lignans. Studies on isoflavones and lignans consumed in different ways have shown inconclusive results regarding effects on menopause symptoms. The main objective in this study was to test the effects of daily consumption of bread produced with partially defatted ground flaxseed that is rich in lignans on the climacteric symptoms and endometrial thickness of postmenopausal patients. The results showed that the control group had significant reductions in plasma HDLC and FSH concentrations after the intervention. Although some biological and clinical assays on flaxseed have shown its ability to reduce total- and LDL-C, this did not occur in the present intervention; these values did not vary during the study. No significant differences in symptoms between the 2 groups were noted after 12 wk of treatment. In both groups, the patients had a significant reduction in the number of hot flashes and in the KMI, in relation to the beginning of the treatment, but the groups did not differ at the end of the treatment. This improvement may be partly related to decreasing willingness to mark the symptoms correctly in the diary as time passed. The authors conclude that, in this trial, the phytoestrogens from flaxseed did not significantly affect menopausal symptoms, compared with placebo. However, this study confirms the importance of the placebo group for comparing the effects of other treatments on these symptoms. (Editors comments)
