Effect of Flaxseed Consumption on Urinary Levels of Estrogen Metabolites in Postmenopausal Women

Abstract

Flaxseed is a rich source of dietary lignans. It has been hypothesized that lignans may decrease breast cancer risk through modulation of endogenous hormone levels. The aim of this study was to determine the effect of flaxseed supplementation on urinary levels of estrogen metabolites that may be involved in the development of breast cancer. Forty-three postmenopausal women participated in this 12-wk preintervention-postintervention study. Participants consumed 7.5 g/day of ground flaxseed for 6 wk, followed by 15 g/day for an additional 6 wk. The mean urinary level of 16alpha -hydroxyestrone (16alpha -OHE1) was higher at the end of 12 wk compared to baseline (change of 1.32 ug/day, P = 0.02). There was no significant change in 2-OHE1 excretion. The mean urinary level of the 2-OHE1/16alpha -OHE1 ratio was lower at the end of 12 wk compared to baseline (change of -1.1, P = 0.02). Mean urinary excretion of 2-methoxyestradiol was also lower at 12 wk than at baseline (P = 0.03). Based on the current paradigm of the effects of estrogen metabolism on breast cancer risk, the regimen of dietary flaxseed intake used in this study did not appear to favorably alter breast cancer risk through shifts in estrogen metabolism pathways in postmenopausal women.

Dietary Intervention of Flaxseed: Effect on Serum Levels of IGF-1, IGF-BP3, and C-Peptide

“…Similarly, there was no change in serum levels of C-peptide after 6 and 12 wk of flaxseed ingestion. As we previously reported (15), there was a suggestion of a decline in total energy intake between the first and second follow-up visits (-96.6 kcal/day, P = .15), consistent with small statistically significant declines in several macronutrients and micronutrients (total fat, total protein, vegetable protein, carbohydrates, total fiber, insoluble fiber, and linolenic acid). The results in Table 2 were essentially unchanged after adjustment for these factors.…”

Oilseeds ameliorate metabolic parameters in male mice, while contained lignans inhibit 3T3-L1 adipocyte differentiation in vitro

“…Lignans are expected to have beneficial effects in humans after fermentative conversion in the colon to the mammalian lignans ENL and END [13,14]. Subpopulations with higher consumption of lignans display considerable lower disease frequency [7,[15][16][17][18][19][20][21][22]. In several studies, lignan-rich foods, concentrates or partially purified compounds have been shown to improve blood lipids, to enhance glycemic control and to alleviate or cure type 1 and type 2 diabetes [23][24][25][26][27].…”

Redefining Unusable Weeds to Beneficial Plants: Purslane as a Powerful Source of Omega-3 for the Future

“…Estrogens are three biochemically distinct molecules the body produces naturally and they include estrone (E1), estradiol (E2), and estriol (E3) (Sturgeon et al, 2010). There is no report in the literature on anti-estrogenic activity of omega-3 from purslane.…”

“…Estradiol is the major biologically active estrogen in women. Excessive amounts of estrogen can increase the risk for hormone sensitive cancers such as breast or ovarian cancers (Sturgeon et al, 2010 …”