A phase III, randomized, placebo-controlled, double-blind trial of flaxseed for the treatment of hot flashes

Abstract

Objective Preliminary data suggest that flaxseed, a rich source of dietary lignans, may be a potentially effective treatment for hot flashes. A phase III randomized, placebo controlled trial was conducted to evaluate the efficacy of flaxseed in reducing hot flashes. Methods Postmenopausal women with or without breast cancer were randomly assigned to a flaxseed bar (providing 410 mg of lignans) for 6 weeks vs. a placebo bar. Participants completed daily, prospective, hot flash diaries during the baseline week, and then ate one study bar/day for 6 weeks while recording their daily hot flashes. The intra-patient difference in hot flash activity between baseline and the last treatment week was the primary endpoint. Side effects were evaluated through self report and CTC assessment. Results 188 women were enrolled onto this trial. Mean hot flash score was reduced 4.9 in the flaxseed group and 3.5 in the placebo group (p=.29). In both groups, a little over a third of the women received a 50% reduction in their hot flash score. Only one side effect was significantly different between groups, grade 1 pruritis, which was more common in the placebo group (8% versus 1%). Both groups reported abdominal distension, flatulence, diarrhea and nausea. Adherence and ability to detect treatment assignment did not differ between groups. Conclusions The results of this trial do not support the use of 410 mg of lignans for the reduction of hot flashes. The bars were fairly well tolerated, with both groups reporting gastrointestinal effects, likely due to the fiber content.

Exogenous Hormonal Regulation in Breast Cancer Cells by Phytoestrogens and Endocrine Disruptors

“…The effects are further influenced by age, health status and, in case of dietary assumption, by the quality of the gut microflora that contributes to the metabolic conversion of phytoestrogens [130]. The assumption of phytoestrogens during infancy and puberty could be dangerous [14, 23, 131, 132] whereas their use for the treatment of post-menopausal women is thought to provide benefits without serious adverse effects [126, 133]. The antioxidant properties of many phytoestrogens may contribute to prevent the formation of estrogen-DNA adducts, thus preventing ER independent carcinogenic activities [114, 134].…”

Management of Potential Long-Term Toxicities in Breast Cancer Patients

“…These include soy products (69–71), black cohosh (72), magnesium oxide (73), flaxseed (74) and vitamin E (75). Prescription drugs that do seem to reduce hot flashes include clonidine (76, 77) selective serotonergic and/or noradrenergic reuptake inhibitors (SSRIs and/or SNRIs) (78–88), and gabapentin (89–92).…”

North Central Cancer Treatment Group N10C2 (Alliance)

“…13 Furthermore, antidepressants have a stigma for many patients. While herbs and dietary supplements such as soy, black cohosh, flaxseed and vitamin E are popular hot flash remedies, to date, randomized placebo-controlled trials have not proven them to be effective 14–18 .…”