Male Fertility · Male Factor Treatment

Systematic Review and Critical Analysis on Dietary Supplements for Male Infertility: From a Blend of Ingredients to a Rationale Strategy

Garolla A, Petre GC, Francini-Pesenti F, De Toni L, Vitagliano A, Di Nisio A, Grande G, Foresta C

Published February 4, 2022 Frontiers in endocrinology, 2021
DOI 10.3389/fendo.2021.824078 PMID 35185789 PMC PMC8854851
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RRM Academy Synopsis

Many Italian male infertility supplements list unproven ingredients

Many supplements sold in Italy for male infertility contain ingredients with no trial evidence for sperm health. This review of randomized trials scored each product by its ingredients. Three products landed in the high expected efficacy class, 9 in the lower class and 12 in the class with none.

Key Findings

  • From 1,731 studies examined, the review included 45 randomized trials that reported effects on sperm parameters.
  • Manufacturers used 36 ingredients in all: 18 had a reported effect on at least one sperm parameter and 18 had no evidence.
  • Fifteen supplements held at least 1 ingredient lacking evidence for sperm parameters, and 21 formulations dosed some ingredients below the minimal effective daily dose.
  • Half of the potentially active ingredients had a trial with no or even negative effects. For α-tocopherol, three of six trials were positive and three found no effect.

Interpretation

The authors reviewed randomized trials only, for ingredients in products on an Italian Ministry of Health list. A scoring formula applied to each product's ingredient list gives the efficacy classes, so the classes are estimates of expected efficacy. The authors report that most trials had weak designs, tested ingredient mixtures, and tracked semen results with little attention to pregnancy rates. Since many trials tested combinations, interactions between ingredients cannot be excluded. Findings cover the Italian market.

RRM Context

The authors argue that trials should group men by the cause of infertility, because one sperm change can come from varicocele, infection or testicular impairment. Restorative reproductive medicine shares that principle: find the cause first and treat it. The paper also names pregnancy as the outcome that matters and criticizes trials that report semen results without it.

Abstract

Content

Dietary supplements (DS) for male infertility marketed in Italy were evaluated for composition, concentration of ingredients, and recommended daily dose. A systematic review of literature identified ingredients potentially effective on sperm parameters and their minimal effective daily dose (mED).

Objective

This study was conducted in order to critically evaluate the composition and efficacy of DS marketed in Italy.

Design, Setting, and Participants

This was a systematic review of randomized controlled trials.

Evidence Acquisition

A formula allowed us to classify the expected efficacy of each DS, based on composition. Each DS was scored and included into three classes of expected efficacy: high, low, and none.

Evidence Synthesis

Among 24 supplements, 3 (12.5%) fall in high, 9 (37.5%) in lower, and 12 (50.0%) in no expected efficacy class. DS composition showed 36 substances, 18 with no literature on male fertility and 18 showing positive effect on sperm parameters, thus considered potentially active ingredients (PAI). All DS were mixtures of ingredients, containing from 2 to 17 different substances. Fifteen supplements (65.2%) contained at least 1 ingredient without evidence of efficacy and 21 formulations had PAI dosed below mED. Some PAI were associated to the improvement of specific sperm parameters.

Conclusions

DS were usually blends of many substances that are frequently employed at negligible dose or without any evidence of efficacy on male reproduction. Some ingredients have been demonstrated to be effective on specific sperm parameters by RCTs. We report a list of ingredients with potential efficacy on specific sperm parameters, aimed to allow a tailored use of DS.

Patient Summary

The market of DS for male infertility offers products with potential efficacy in the improvement of sperm parameters but also many with uncertain effects. Based on current scientific literature, our study can help in the choice of DS that are more likely to be effective on specific sperm alterations, so providing the best supplementation for each patient.

Topics

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Related research

Male Fertility › Male Factor Treatment › Medical Management · Therapeutics › Supplements and Botanicals › Antioxidant Supplements · Research Methods › Evidence Synthesis › Systematic Reviews
Gabriel Cosmin Petre, Francesco Francini-Pesenti, L De Toni, Amerigo Vitagliano, A Di Nisio
G Petre, F Francini-Pesenti, A Vitagliano
PMID 35185789 35185789 DOI 10.3389/fendo.2021.824078 10.3389/fendo.2021.824078 Garolla et al. 2021, Garolla 2021