Antioxidants for male subfertility

Current drawbacks and future perspectives in the diagnosis and treatment of male factor infertility, with a focus on FSH treatment: an expert opinion

PURPOSE

Infertility is defined as the inability to conceive after 1 year of unprotected intercourse, affecting approximately 15-20% of couples in Western countries. It is a shared problem within the couple; when the main issue lies with one of the partners, it is preferable to refer to "male factor" or "female factor" infertility rather than simply male or female infertility. Despite male factor infertility accounting for half of all couple infertility cases, the clinical approach to the male partner is not uniformly standardized across international guidelines.

METHODS

To provide an expert overview, we have comprehensively reviewed and critically analyzed the most up-to-date literature on this sensitive topic, leading to the development of a proposal for tailored assessment of the diagnostic-therapeutic pathway and preventive strategies. The diagnostic approach also considers that infertile men are objectively less healthy than their fertile counterparts of the same age and ethnicity.

RESULTS

This article discusses the diagnostic flow, the classification of male factor infertility, the definition of idiopathic infertility, the involvement of general health, and treatment recommendations, emphasizing follicle-stimulating hormone treatment in selected groups of patients.

CONCLUSION

We provide expert opinion on current drawbacks and future perspectives in this field, with practical advice for the clinical practice of general practitioners and expert in reproductive medicine.

Analyzing free fatty acids in seminal plasma from asthenozoospermia patients undergoing antioxidant therapy

OBJECTIVE

Different aspects of the functions of free fatty acid (FFA) in seminal plasma and their implications on male fertility are known. However, the profile of FFA in seminal plasma in asthenozoospermic patients following antioxidant therapy has not been studied.

METHODS

In this case-control study, the total antioxidant capacity (TAC) and FFA profile of the seminal plasma were determined in 80 patients (29 normozoospermic volunteers and 51 asthenozoospermic men) who were treated with antioxidants for three months.

RESULTS

The TAC level in normozoospermic men was significantly higher than in asthenozoospermic men before and after antioxidant therapy with even lower values after the treatment (p=0.0001). The most abundant identified FFAs in seminal plasma were palmitic acid, vaccenic acid, eicosatrienoic acid, stearic acid, and myristoleic acid. Palmitic acid was lower in asthenozoospermic patients (p=0.0001), and antioxidant treatment restored its level to near-control levels. Compared to normozoospermic controls, the level of eicosatrienoic acid is significantly lower in asthenozoospermia patients before (p=0.01) and after treatment (p=0.0001). Additionally, following oral antioxidant supplementation, the FFA pattern in asthenozoospermic patients changes to the pattern observed in normozoospermic men. However, these changes are not statistically significant.

CONCLUSIONS

The TAC level in asthenozoospermic patients after antioxidant treatment did not change to the levels in the control group; it even dropped to a lower level following three months of treatment. Antioxidant treatment can change the level of the FFA compositions of seminal plasma.

Kidney disease and reproductive health

Understanding the relationship between reproductive health and kidney function is important to provide holistic care for people living with kidney disease. Chronic kidney disease (CKD) has negative impacts on both male and female fertility owing to factors including inflammation, hormonal dysregulation, reduced ovarian reserve, reduced sperm quality and sexual dysfunction. However, pregnancy is achievable for most cisgender women with kidney disease, including kidney transplant recipients and patients on dialysis. CKD in pregnancy is associated with health risks to the mother and child, including increased risk of progression of kidney disease, hypertensive complications of pregnancy, and neonatal complications including fetal growth restriction, preterm birth and stillbirth. However, with appropriate pre-pregnancy counselling, fertility assessment and support, health optimization, and evidence-based antenatal care, the majority of patients will achieve a good outcome. Medication safety should be reviewed before and during pregnancy and lactation, weighing the risk of disease flare against potential adverse effects on the offspring. Important areas for further research include the optimal timing of delivery and the short- and long-term cardiovascular and renal impacts of pregnancy in patients with CKD, as well as long-term kidney and cardiovascular outcomes in their offspring.

Sperm DNA Fragmentation and Fertility

Elevated levels of sperm deoxyribonucleic acid (DNA) fragmentation (SDF) have been associated with several adverse reproductive outcomes, including: lower natural and assisted reproductive technology (ART) pregnancy rates, abnormal embryo development, and recurrent pregnancy loss. However, due to conflicting study results, limited high-level evidence, multiple clinically available assays, and variable standard reference ranges, precisely how SDF testing should be applied to the evaluation and treatment of infertile men remains controversial. To better understand SDF and its role in clinical practice, this chapter aims to: (1) review the literature that has made SDF such a controversial topic, (2) discuss newly published evidence contributing to this complex discussion, and (3) outline the most recent practice guidelines currently available.

Impact of Reductive Stress on Human Infertility: Underlying Mechanisms and Perspectives

Antioxidants have a well-established effect on general health and are essential in preventing oxidative damage to cells by scavenging free radicals. Free radicals are thought to be neutralized by these substances, which include polyphenols, β-carotene, and vitamins C and E, reducing cellular damage. On the other hand, recent data indicates that consuming excessive amounts of antioxidants may have side effects. Apoptosis and cell signaling are two beneficial physiological processes that are affected by excessive supplementation. Other negative effects include paradoxical enhancement of oxidative stress and unbalanced cellular redox potential. Overdosing on particular antioxidants has been associated with increased medication interactions, cancer progression, and fatality risks. Additionally, the complex impacts they may have on fertility might be both useful and adverse, depending on the quantity and duration of usage. This review delves into the dual role of antioxidants and emphasizes the importance of employing antioxidants in moderation. Antioxidant overconsumption may disrupt the oxidative balance necessary for normal sperm and oocyte function, which is one of the potential negative effects of antioxidants on fertility in both males and females that are also investigated. Although modest usage of antioxidants is generally safe and useful, high levels of antioxidants can upset hormonal balance, impair sperm motility, and negatively impact the outcomes of assisted reproductive technologies (ART). The findings emphasize the need to use antioxidant supplements in a balanced way, the importance of further research to optimize their use in fertility treatments, and the importance of supporting reproductive health to avoid adverse effects.

Comprehensive review of the traditional uses and the potential benefits of epimedium folium

Epimedium Folium has been extensively utilized for medicinal purposes in China for a significant period. This review undertakes a comprehensive examination of literature pertaining to Epimedium and its metabolites over the past decade, drawing from databases such as PubMed. Through meticulous organization and synthesis of pertinent research findings, including disease models, pharmacological effects, and related aspects, this narrative review sheds light on the principal pharmacological activities and associated mechanisms of Epimedium in safeguarding the reproductive system, promoting bone health, mitigating inflammation, and combating tumors and viral infections. Consequently, this review contributes to a more profound comprehension of the recent advances in Epimedium research.

From Bench to Babies - Drug Development for Male Subfertility

Infertility is estimated to affect more than 50 million couples around the world, with male factor accounting for half of these cases, yet there is a notable absence of effective treatment options for men, other than in-vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). This review considers unlicensed and empirical treatments used for male subfertility, including hormonal therapy, phosphodiesterase inhibitors, and antioxidants. Compounds generally demonstrate variable improvements in sperm function but benefits for fertility are less clear. There is a pressing need for effective treatment options for subfertile men, however, our knowledge of sperm function is limited, restricting the identification of precise treatment targets. The traditional drug discovery pathway is also notorious for its extensive resource and time requirements, often extending over decades and demanding significant financial investment. Unfortunately, a substantial number of potential therapies fail before reaching the marketplace. Furthermore, reliance on mammalian models is not possible in the drug development process for male subfertility, due to significant variability between animals and man. We review recent breakthroughs and highlight novel methods aimed at improving the effectiveness and efficiency of drug discovery for male subfertility. High-throughput screening, combinatorial chemistry, and the repurposing of established medications have great potential. These strategies offer the promise of accelerating the pace of drug development, curbing the extensive demand for resources, and, in the case of drug repurposing, diminish the demand for comprehensive pharmacokinetic and pharmacodynamic studies. As these innovative approaches are adopted, the feasibility of addressing male subfertility through scientific advancements appears to be increasingly attainable.

Impact of sperm DNA fragmentation in couples with unexplained recurrent pregnancy loss: A cross-sectional study

OBJECTIVE

Recurrent pregnancy loss (RPL) has a multifactorial etiology, with a majority of cases remaining unexplained. To account for these unexplained cases, possible male factors are being explored. Conventional semen analysis lacks a qualitative assessment of sperms and information regarding sperm DNA integrity. Sperm DNA fragmentation (SDF) has diagnostic value in unexplained RPL, and it may account for a number of unexplained cases. Hence, we planned a study to explore and evaluate the impact of sperm DNA fragmentation in couples with unexplained recurrent pregnancy losses.

STUDY DESIGN

Analytical cross-sectional study was conducted at a tertiary-level referral facility in India between August 2021 and July 2023. Participants (n = 70) were divided into two groups-male partners of couples with unexplained RPL (following spontaneous conceptions) (n = 35) and men with at least one previous live birth (spontaneous or following fertility treatments for female factor infertility such as ovulation induction or intrauterine insemination) as controls (n = 35). Neither of the two groups of couples recruited for this study had undergone ART as fertility treatment. Primary outcome assessed was mean DNA fragmentation index (DFI). Secondary outcomes included differences in semen parameters such as sperm concentration, progressive sperm motility and morphology, proportion of men with high (≥30%) and low DFI in the two groups, and the association between various semen parameters and DFI.

RESULTS

Univariate logistic regression revealed that sperm DNA fragmentation was higher in men with unexplained RPL (30.0; IQR (interquartile range) 19.0, 46.0) as compared to controls (22.0; IQR 14.0, 30.0) although it was not statistically significant (OR, odds ratio, 1.02; 95% CI 1.0-1.1, p = 0.08). A higher proportion of men with unexplained RPL had DFI ≥30% compared to controls (54.2% vs. 25.7%; OR 3.43 (95% CI 1.2-9.4); p = 0.02). No statistically significant differences were observed in semen volume, sperm concentration, progressive motility, and morphology between the two groups. Sperm DNA fragmentation index also showed a weak but significant inverse relationship with sperm morphology (r = -0.336, p = 0.004).

CONCLUSION

The current study did not show any significant difference in the mean sperm DNA fragmentation levels in male partners of couples with unexplained RPL compared to controls. However, a higher proportion of men with DFI ≥30% were observed in unexplained RPL population when compared to controls.

Micronutrient Antioxidants for Men (Menevit®) Improve Sperm Function by Reducing Oxidative Stress, Resulting in Improved Assisted Reproductive Technology Outcomes

Oxidative stress (OS) affects men's health and impairs spermatogenesis. Micronutrient antioxidants are available for male infertility as complemental support; however, their efficacy remains debatable. This study aimed to investigate whether antioxidants can help to reduce sperm OS and improve semen analysis and quality. We included 171 male partners of couples planning to undergo assisted reproductive technology (ART). Male partners, aged 29-41 years, of couples intending to conceive were self-selected to take daily antioxidants (n = 84) containing folic acid and zinc, or not to take antioxidants (n = 52) for 6 months. We analyzed the alterations in serum oxidant levels, sperm parameters, OS, and deoxyribonucleic acid fragmentation after 3 and 6 months. Additionally, implantation, clinical pregnancy, and miscarriage rates after vitrified-warmed embryo transfer were compared between those taking antioxidants and those not taking them after 6 months. In men with high static oxidation-reduction potential (sORP), we observed a significant improvement in sperm concentration and sORP. The high-quality blastocyst rate tended to increase, and implantation and clinical pregnancy rates also significantly increased after 6 months of intervention. The micronutrient antioxidants could improve sperm function by reducing OS and improving ART outcomes. Therefore, micronutrient antioxidants may be a viable treatment option for male infertility.

Effect of antioxidants on semen parameters in men with oligo-astheno-teratozoospermia: a network meta-analysis

BACKGROUND

Although antioxidants are largely used in subfertile men with oligo-astheno-teratozoospermia (OAT), the choice among different molecules is challenged by the lack of comparative head-to-head studies. The network meta-analysis (NMA) can overcome limitations of pairwise meta-analyses, since it incorporates direct and indirect evidence into a single model generating an effectiveness hierarchy.

OBJECTIVE

To assess with a NMA the effects of antioxidants in improving seminal parameters in idiopathic OAT.

MATERIALS AND METHODS

PubMed, Scopus, Cinahl, and Cochrane Library databases were searched for randomized controlled trials (RCTs) comparing any antioxidant treatment to each other or placebo in men with at least one idiopathic seminal abnormality. Data were included in a random-effects NMA, where efficacy of treatments was ranked by surface under the cumulative ranking curve (SUCRA).

RESULTS

29 RCTs provided information on 2045 men (mean age: 33.5 years) with idiopathic OAT and 19 antioxidant preparations. Compared to placebo, l-carnitine, especially in combination with l-acetyl-carnitine (LAC), had the highest SUCRA for sperm concentration, progressive motility, and morphology. Folate was the only other compound effective on sperm concentration. Vitamin E+selenium or zinc had the highest SUCRA for total motility. A contribution on progressive motility was revealed for pentoxifylline and vitamin E+CoQ10.

The role of oral antioxidants in the improvement of sperm parameters in infertile men

PURPOSE

A variety of pathologic conditions may increase oxidative stress in semen resulting in structural modifications to spermozoa's plasma membrane that interfere with sperm motility, morphology, and count. Antioxidants are currently being marketed to treat male infertility. In semen, antioxidants may decrease oxidative stress and potentially improve sperm parameters. In this narrative, mini-review we evaluated the effectiveness of antioxidants in infertility.

METHODS

This mini-review of the current literature has been carried out through searching of the PubMed and Google scholar databases.

RESULTS AND CONCLUSIONS

The literature review suggests that there is evidence that oral antioxidants such as selenium, carnitine, zinc, coenzymeQ10, vitamins E and C, etc. alone or in combinations, improve sperm count, motility, morphology as well as pregnancy rates in infertile men with idiopathic oligoasthenospermia. Unfortunately, most of these studies are poorly designed, limited by sample size, varying in dosage, differing in primary end points, and most notably lacking live birth data. Importantly, large randomized, well-designed, placebo-controlled trials are needed.

Frequency, morbidity and equity - the case for increased research on male fertility

Currently, most men with infertility cannot be given an aetiology, which reflects a lack of knowledge around gamete production and how it is affected by genetics and the environment. A failure to recognize the burden of male infertility and its potential as a biomarker for systemic illness exists. The absence of such knowledge results in patients generally being treated as a uniform group, for whom the strategy is to bypass the causality using medically assisted reproduction (MAR) techniques. In doing so, opportunities to prevent co-morbidity are missed and the burden of MAR is shifted to the woman. To advance understanding of men's reproductive health, longitudinal and multi-national centres for data and sample collection are essential. Such programmes must enable an integrated view of the consequences of genetics, epigenetics and environmental factors on fertility and offspring health. Definition and possible amelioration of the consequences of MAR for conceived children are needed. Inherent in this statement is the necessity to promote fertility restoration and/or use the least invasive MAR strategy available. To achieve this aim, protocols must be rigorously tested and the move towards personalized medicine encouraged. Equally, education of the public, governments and clinicians on the frequency and consequences of infertility is needed. Health options, including male contraceptives, must be expanded, and the opportunities encompassed in such investment understood. The pressing questions related to male reproductive health, spanning the spectrum of andrology are identified in the Expert Recommendation.

Recurrent miscarriage and male factor infertility: diagnostic and therapeutic implications. A narrative review

Introduction

Recurrent miscarriage is defined as 2 or more failed clinical pregnancies, typically known as repeated pregnancy loss, occurring before 20 gestational weeks, and further categorized into primary and secondary types. It represents a common and distressing condition to deal with in the field of reproductive medicine, usually affecting <5% of couples, with up to 50% of cases lacking a clearly defined aetiology. The epidemiology also varies depending on maternal age. Remarkably, the situation significantly afflicts expecting parents, whereas maternal factors, such as age and previous pregnancy loss rate, are commonly reported as risk factors. Although previously underestimated, existing evidence suggests the male factor is a possible cause of recurrent pregnancy loss.

Material and methods

A non-systematic literature review was conducted in the PubMed and Scopus databases for articles written in English investigating the possible association of the male factor in recurrent pregnancy loss. The eligible studies were synthesized in a narrative review format upon discussion and consensus among the authors after being previously independently assessed and selected.

Results

Lifestyle, obesity, genetic predisposition, chromosomal anomalies, endocrine dysfunction, anatomical abnormalities, immunological factors, infections, and oxidative stress can result in poor embryo development and recurrent miscarriage. Although professional organizations currently recognize male gender as a possible risk factor, specific recommendations on the diagnostic and therapeutic field are still lacking, and the condition necessitates a high level of suspicion and case-by-case management.

Conclusions

In this review, we delve deeper into the contribution of the male factor in the concept of recurrent miscarriage.

Male infertility

Clinical infertility is the inability of a couple to conceive after 12 months of trying. Male factors are estimated to contribute to 30-50% of cases of infertility. Infertility or reduced fertility can result from testicular dysfunction, endocrinopathies, lifestyle factors (such as tobacco and obesity), congenital anatomical factors, gonadotoxic exposures and ageing, among others. The evaluation of male infertility includes detailed history taking, focused physical examination and selective laboratory testing, including semen analysis. Treatments include lifestyle optimization, empirical or targeted medical therapy as well as surgical therapies that lead to measurable improvement in fertility. Although male infertility is recognized as a disease with effects on quality of life for both members of the infertile couple, fewer data exist on specific quantification and impact compared with other health-related conditions.

Coenzyme Q: food sources, adequate and clinically effective doses

Coenzyme Q (CoQ) plays a key role in cell bioenergetics; it is not only supplied with food, but also synthesized in the body. Endogenous CoQ synthesis decreases with age, with statin use, with cardiovascular, neurodegenerative, and other diseases. In this regard, specialized food products (SFP) enriched with CoQ are being developed. Aim of the review – compare the CoQ doses allowed for use as part of dietary supplements and SFP with doses that provide a clinical effect. Literature review was carried out using the RSCI, Pubmed databases and Google Scholar, ReserchGate systems for the keywords “ubiquinone”, “coenzyme Q10”. The amount of CoQ contained in SFP is set by domestic regulatory documents based on an adequate daily intake for adults (30 mg) and the upper allowable intake level as part of SFP and dietary supplements – 100 mg/day. Actually used doses of CoQ range from 60 to 500 mg/day. Various ways to increase the bioavailability of CoQ have been described. When patients take CoQ, a U-shaped dose-effect relationship is observed, an effective dose that significantly reduces systolic blood pressure, fasting glucose and insulin levels, the degree of hemoglobin glycation, the HOMA-IR glycemic test is in the range of 100–200 mg / day. An improvement in the antioxidant status and a decrease of pro-inflammatory cytokines concentration in the blood plasma of athletes is provided by CoQ doses of 60–300 mg/day, in patients with type 2 diabetes mellitus and coronary heart disease, doses of 100–150 mg/day. Clinically effective doses of CoQ (100–200 mg/day) when used for at least 12 weeks correspond to or are 1.5–2 times higher than the upper allowable consumption level in the composition of SFP and dietary supplements. The inclusion of CoQ in the dietary therapeutic SFP in an amount that does not reach doses that are effective in a certain pathology does not achieve the expected result. A possible way to solve the problem is to increase the acceptable levels of consumption of CoQ in SFP, as well as increasing the bioavailability of CoQ in the composition of emulsions, liposomes, phytosomes and oleogels.

A novel mutation in CFAP47 causes male infertility due to multiple morphological abnormalities of the sperm flagella

Introduction

A previous study suggested that loss of CFAP47 function is involved in multiple morphological abnormalities of the sperm flagella (MMAF) in humans and mice. However, the comprehensive role of CFAP47 in spermatogenesis is largely unknown.

Methods

Whole-exome sequencing (WES) was conducted to identify pathogenic variant in two patients with MMAF. The functional effect of the identified mutations was investigated by immunofluorescence staining and western blotting. Intracytoplasmic sperm injection (ICSI) was used to assist fertilization for the patient with MMAF.

Results

In this study, we identified a novel missense mutation (c.1414G>A; p.V472M) in CFAP47 in two unrelated patients with oligoasthenoteratozoospermia. Intriguingly, in addition to the MMAF phenotype very analogous to the previous report, the two patients notably presented abnormal morphology of sperm heads, the sperm mitochondrial sheath was obviously disorganized, and the sperm annulus were almost defective. Further functional experiments confirmed that the expression of CFAP47 was markedly reduced in the spermatozoa of the patients. Mechanism analysis suggested that CFAP47 might regulate the expression of CFAP65, CFAP69 and SEPTIN4 through their physical interactions and thus modulating sperm morphogenesis.

Conclusion

we revealed a novel mutation in CFAP47 and further expanded the phenotype and mutation spectrum of CFAP47, as well as the potential mechanism of CFAP47 manipulating spermatogenesis, finally providing important guidance for genetic counseling and targeted treatment for CFAP47 mutation-related male infertility.

The lack of evidence behind over-the-counter antioxidant supplements for male fertility patients: a scoping review

STUDY QUESTION

What is the evidence for over-the-counter antioxidant supplements for male infertility?

SUMMARY ANSWER

Less than half of over-the-counter antioxidant supplements for male fertility patients have been tested in a clinical trial, and the available clinical trials are generally of poor quality.

WHAT IS KNOWN ALREADY

The prevalence of male infertility is rising and, with this, the market for supplements claiming to improve male fertility is expanding. Up to now, there is limited data on the evidence for these over-the-counter supplements.

STUDY DESIGN SIZE DURATION

Amazon, Google Shopping and other relevant shopping websites were searched on 24 June 2022 with the following terms: 'supplements', 'antioxidants', 'vitamins', AND 'male fertility', 'male infertility', 'male subfertility', 'fertility men', 'fertility man'. All supplements with a description of ingredients in English, Dutch, French, Spanish, or German were included. Subsequently, Pubmed and Google Scholar were searched for studies that included the supplements.

PARTICIPANTS/MATERIALS SETTING METHODS

Inclusion criteria were supplements with antioxidant properties, of which the main purpose was to improve male fertility. Included supplements must be available without a doctor's prescription. Supplements containing plant extracts were excluded, as well as supplements of which the content or dosage was not clear. The ingredients, dosage, price and health claims of the supplements were recorded. We assessed whether substances in the supplements exceeded the recommended dietary allowance (RDA) or tolerable upper intake level (UL). All clinical trials and animal studies investigating included supplements were selected for this review. Clinical trials were assessed for risk of bias with a risk of bias tool appropriate for the study design.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 34 eligible antioxidant supplements found, containing 48 different active substances. The average price per 30 days was 53.10 US dollars. Most of the supplements (27/34, 79%) contained substances in a dosage exceeding the recommended daily allowance (RDA). All manufacturers of the supplements made health claims related to the improvement of sperm quality or male fertility. For 13 of the 34 supplements (38%), published clinical trials were available, and for one supplement, only an animal study was found. The overall quality of the included studies was poor. Only two supplements were tested in a good quality clinical trial.

LIMITATIONS REASONS FOR CAUTION

As a consequence of searching shopping websites, a comprehensive search strategy could not be formulated. Most supplements were excluded because they contained plant extracts or because supplement information was not available (in an appropriate language).

WIDER IMPLICATIONS OF THE FINDINGS

This is the first review that gives an insight into the market of male fertility supplements as available to infertility patients and other men seeking to improve their fertility. Earlier reviews have focused only on supplements with published clinical trials. However, we show that more than half of the supplements have not been tested in a clinical trial. To our knowledge, this review is the first to assess the dosage of supplements in relation to the RDA. In agreement with the literature, we found that the evidence on male fertility supplements is generally of poor quality. This review should urge pharmaceutical companies to evaluate their products in randomized controlled trials in order to provide people with substantiated information.

STUDY FUNDING/COMPETING INTERESTS

The research position of W.R.d.L. is funded by an unrestricted grant from Goodlife Pharma. W.R.d.L., K.F., and J.P.d.B. are in the research team of a clinical trial on Impryl®, one of the supplements included in this review.

REGISTRATION NUMBER

N/A.

Dietary trends and the decline in male reproductive health

Over the twentieth century, male reproductive health has suffered a substantial decline, as evidenced by decreases in sperm counts and testosterone levels and increases in reproductive pathologies. At the same time, the prevalence of chronic diseases such as obesity, diabetes, and metabolic syndrome has risen dramatically. Metabolic and reproductive health are highly interconnected, suggesting that their respective trends are intertwined and, given the timeframe of such trends, environmental and not genetic factors are most likely to be the primary causes. Industrialization, which began in Europe in the mid-eighteenth century, has resulted in profound changes to our diet, lifestyle, and environment, many of which are causal factors in the rise in chronic diseases. Industrialization results in a nutrition transition from an agricultural unprocessed to a modern processed diet, incorporating increases in sugar, vegetable oils, ultra-processed foods, linoleic acid, trans-fats, and total energy. This dietary shift has incurred numerous adverse effects on metabolic and reproductive health, characterized by chronic inflammation, oxidative stress, and insulin resistance. Moreover, these effects appear to multiply across subsequent generations via epigenetic inheritance. Men's fertility is markedly affected by obesity and diabetes, with an increase in total energy via processed food intake arguably being the key factor driving the diabesity pandemic. In contrast, wholefoods rich in micronutrients and phytonutrients support male fertility and a healthy body weight. Therefore, men wanting to maximize their fertility should consider making positive dietary changes, such as replacing processed foods with unprocessed foods that support metabolic and reproductive health.

From Oxidative Stress to Male Infertility: Review of the Associations of Endocrine-Disrupting Chemicals (Bisphenols, Phthalates, and Parabens) with Human Semen Quality

Exposure to endocrine-disrupting chemicals (EDCs) may result in oxidative stress and endocrine system disturbance, which can have an impact on human reproduction and development. In male reproductive health, EDCs have been related to impaired reproductive function and male infertility, altered fetal development, and testicular germ-cell, prostate, and breast cancers. We conducted an electronic search using PubMed on endocrine disruptors related to oxidative stress and male infertility, and evaluated their association with endocrine-disrupting chemicals (bisphenols, phthalates, and parabens) in 25 articles. Higher levels of urinary bisphenols showed correlation with impaired semen quality and increased DNA damage. Considering phthalates and their metabolites, all studies found a positive association between urinary levels of phthalates and at least one semen parameter indicative of low semen quality; some studies also revealed sperm DNA damage. The studies on parabens less often revealed correlation of urinary parabens concentrations with a decrease in sperm count, as well as motility and DNA damage. Moreover, EDCs can elevate ROS production and lipid peroxidation, increase apoptosis, induce epigenetic modifications, and change the Y:X sperm chromosome ratio and sperm protein composition. Our review revealed detrimental effects of EDCs on semen quality and sperm DNA integrity-especially in BPA and phthalates, but also in parabens.

Sperm as a Carrier of Genome Instability in Relation to Paternal Lifestyle and Nutritional Conditions

Endogenous and exogenous factors can severely affect the integrity of genetic information by inducing DNA damage and impairing genome stability. The extent to which men with and without subfertility are exposed to several adverse lifestyle factors and the impact on sperm DNA fragmentation (SDF), sperm chromatin maturity (condensation and decondensation), stability (hypo- and hypercondensation) and sperm aneuploidy are assessed in this study. Standardized assays employing flow cytometry were used to detect genome instability in 556 samples. Semen parameters deteriorated with age, BMI, increased physical activity and smoking. Age and BMI were associated with increased SDF. Increased BMI was associated with increased hypocondensed chromatin and decreased decondensed chromatin. Increase in age also caused an increase in sex chromosome aneuploidy in sperms. Surprisingly, alcohol abuse reduced chromatin hypercondensation and drug abuse reduced SDF. Although genome instability was more pronounced in the subfertile population as compared to the fertile group, the proportion of men with at least one lifestyle risk factor was the same in both the fertile and subfertile groups. While one in three benefited from nutritional supplementation, one in five showed an increase in SDF after supplementation. Whilst the message of ‘no smoking, no alcohol, no drugs, but a healthy diet’ should be offered as good health advice, we are a long way from concluding that nutritional supplementation would be beneficial for male fertility.