Evidence map›Paper›PMID 41527991›Full record

ArticleAsian journal of andrology2026

Urinary isoflavone concentrations and semen parameters of Japanese men seeking fertility treatment.

Shoko Konishi, Yuki Mizuno, Kazumitsu Yamasaki, Masahiro Uchida, Teruaki Iwamoto

Abstract read
In one paragraph

Article in Asian journal of andrology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Shoko KonishiDepartment of Human Ecology, School of International Health, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan.
Yuki MizunoDepartment of Human Ecology, School of International Health, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033, Japan.
Kazumitsu YamasakiDepartment of Urology, Tsukuba Gakuen Hospital, 2573-1 Kamiyokoba, Tsukuba, Ibaraki 305-0854, Japan.
Masahiro UchidaDepartment of Urology, Tsukuba Gakuen Hospital, 2573-1 Kamiyokoba, Tsukuba, Ibaraki 305-0854, Japan.
Teruaki IwamotoSanno Hospital, Tokyo 170-0052, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

This study aimed to analyze the associations between urinary genistein, daidzein, and equol concentrations and semen parameters in Japanese men exposed to high levels of isoflavone in their diet. Between September 2020 and March 2021, men seeking fertility treatment (n = 157) at Sanno Hospital (Tokyo, Japan) and Tsukuba Gakuen Hospital (Ibaraki, Japan) provided spot urine and semen specimens on the same day. Sperm concentration, sperm count, and total sperm motility were quantified. Urinary isoflavones were measured using liquid chromatography-tandem mass spectrometry and adjusted for specific gravity. The median (interquartile range [IQR]) total sperm count and concentration were 112 × 10 6 (50 × 10 6 , 221 × 10 6 ) and 39 × 10 6 (17 × 10 6 , 72 × 10 6 ) ml -1 , respectively. Men in the second, third, and fourth quartile of urinary daidzein concentration had -40% (95% confidence interval [CI]: -59%, -13%), -37% (95% CI: -56%, -9%), and -32% (95% CI: -53%, -3%) low sperm count, respectively, than those in the lowest quartile. Men in the second, third, and fourth quartile of urinary genistein concentration had -23% (95% CI: -47%, 12%), -50% (95% CI: -66%, -26%), and -29% (95% CI: -51%, 3%) low sperm count than those in the lowest quartile, respectively. Sperm count showed no association with urinary equol concentration ( P > 0.05). No associations were observed between urinary isoflavones and total sperm motility. A higher isoflavone intake may be associated with reduced sperm concentration and count. The effect of these alterations in semen parameters on the fecundity of couples trying to conceive remains unknown.

Indexed as

Infertility, MaleIsoflavonesAdultEquolGenisteinHumansJapanMaleSemen AnalysisSperm CountSperm MotilitydaidzeinEquolGenisteinIsoflavonesAsiadaidzeinequolgenisteinsemen

Identifiers

PMID41527991
PMCPMC13258347

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.