Usual dietary isoflavone intake and reproductive function across the menstrual cycle

Amanda C Filiberto; Sunni L Mumford; Anna Z Pollack; Cuilin Zhang; Edwina H Yeung; Karen C Schliep; Neil J Perkins; Jean Wactawski-Wende; Enrique F Schisterman

doi:10.1016/j.fertnstert.2013.08.002

Lifestyle and Environment Nutrition and Metabolic Health

Usual dietary isoflavone intake and reproductive function across the menstrual cycle

Filiberto AC, Mumford SL, Pollack AZ, Zhang C, Yeung EH, Schliep KC, Perkins NJ, Wactawski-Wende J, Schisterman EF

Published December 2013 Fertility and sterility, 100(6), 1727-1734

DOI 10.1016/j.fertnstert.2013.08.002 PMID 23998910 PMC PMC3867935

RRM Academy Synopsis

Isoflavone intake in healthy women was not linked to missed ovulation

A prospective cohort of 259 healthy women with regular periods found usual dietary isoflavone intake was not associated with cycles lacking ovulation. The women were followed for up to two cycles. Intake was also not associated with estradiol, LH or FSH. The highest-intake group had slightly higher SHBG, a protein that carries sex hormones in blood.

About 1 in 10 women had a cycle without ovulation during the study. Source: Filiberto AC et al., 2013, PMID 23998910.

Study at a glance, prospective cohort: Isoflavone intake in healthy women was not linked to missed ovulation — Study at a glance, prospective cohort of 259 healthy women: Isoflavone intake in healthy women was not linked to missed ovulation. Source: Filiberto AC et al., 2013, PMID 23998910.

Key Findings

Of 259 women followed for up to two cycles, 35 (14%) had a cycle without ovulation: 28 (11%) had one such cycle and seven (3%) had two.
Women in the highest quartile of isoflavone intake showed no association with cycles lacking ovulation, compared with the lowest quartile (adjusted odds ratio 0.87, 95% CI 0.32–1.66).
Isoflavone intake showed no statistically significant association with total estradiol, free estradiol, or LH and FSH around ovulation.
In some models, luteal progesterone showed a modest positive association with intake in the second and third quartiles relative to the lowest, with no significant trends.
The highest quartile had greater SHBG than the lowest (β = 0.09; 95% CI 0.02–0.16; model 3), with hormones analyzed on the log scale.

Interpretation

This cohort study followed 259 healthy women with regular periods for up to two cycles. The researchers timed hormone draws to each woman's own cycle phases with fertility monitors, then tracked usual diet against ovulation and hormone levels. Their diets were close to typical American diets, the authors say. Isoflavone intake was linked with higher SHBG, a protein that carries sex hormones in the blood and is tied to a more favorable metabolic profile. The authors call for further studies that extend to time-to-pregnancy outcomes. The findings support larger studies of isoflavone intake and reproductive hormones.

RRM Context

Restorative reproductive medicine reads hormone results against the timing of the cycle, with ovulation as its central event. The BioCycle team timed clinic visits to each woman's own cycle phases using fertility monitors. The authors cite monitors catching the LH surge in over 75% of cycles, against 37% to 57% for calendar or cycle-length methods.

Our editorial summary of this paper, not the article's abstract.

Abstract

Objective

To assess the association of total isoflavone intake with ovulatory function, including sporadic anovulation in healthy premenopausal women.

Design

Prospective cohort study.

Setting

University.

Patients

Participants included 259 healthy regularly menstruating women aged 18-44 years.

Interventions

None.

Main Outcome Measures

Serum concentrations of E2, free E2, P, LH, FSH, and SHBG and sporadic anovulation in healthy premenopausal women.

Results

Isoflavone intake was not associated with E2, free E2, P, LH, and FSH concentrations. Consumption in the highest quartile (Q4: 1.6-78.8 mg/d) was significantly associated with greater SHBG concentrations (β = 0.09; 95% confidence interval [CI] 0.02-0.16), compared with the first quartile (Q1: 0.0-0.3 mg/d).

Conclusions

Isoflavone intake was not associated with sporadic anovulation (Q4 vs. Q1: odds ratio 0.87, 95% CI 0.32-1.66). Dietary isoflavone intake among young premenopausal women was not related to sex hormone concentrations or anovulation, but was associated with minimally increased SHBG concentrations. These results suggest potential endocrine effects with no subsequent effects on ovulation, easing concerns regarding their impacts on fertility.

Topics

Lifestyle and Environment › Nutrition and Metabolic Health › Dietary Patterns · Reproductive Endocrinology › Ovarian Hormones › Estrogen · Menstrual Cycle › Cycle Physiology › Ovulation

Amanda C Filiberto, Sunni L Mumford, Anna Z Pollack, Cuilin Zhang, Edwina H Yeung, Karen C Schliep, Neil J Perkins, Jean Wactawski-Wende, Enrique F Schisterman

A Filiberto, S Mumford, A Pollack, C Zhang, E Yeung, K Schliep, N Perkins, J Wactawski-Wende, E Schisterman

PMID 23998910 23998910 DOI 10.1016/j.fertnstert.2013.08.002 10.1016/j.fertnstert.2013.08.002 Filiberto et al. 2013, Filiberto 2013

Usual dietary isoflavone intake and reproductive function across the menstrual cycle

Isoflavone intake in healthy women was not linked to missed ovulation

Key Findings

Interpretation

RRM Context

Abstract

Topics

By this author

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