The Role of Dietary Nutrients in Male Infertility: A Review

A comparison of the expression patterns and diagnostic capability of the ncRNAs NEAT1 and miR-34a in non-obstructive azoospermia and severe oligospermia

Infertility is a major global health problem, affecting 8-12% of couples worldwide, with male causes contributing to approximately 50% of cases. Notably, around 15% of infertile men are azoospermic. Consequently, there is a critical necessity to find noninvasive biomarkers to help in diagnosing and assessing the susceptibility of patients with various infertility disorders. This study is designed to determine the roles of NEAT1 and miR-34a as diagnostic and susceptibility biomarkers for non-obstructive azoospermia and severe oligospermia. The interactions between these non-coding RNA (ncRNAs) were explored, along with their correlations to hormonal profiles and clinical parameters like sperm count and motility. The potential of serum NEAT1 and miR-34a as diagnostic biomarkers for these conditions was explored. The study included 100 participants: 40 non-obstructive azoospermia patients, 40 severe oligospermia patients, and 20 healthy controls. Quantitative real-time PCR and transcriptomics-based bioinformatics tools were employed to explore the co-expression networks and molecular interactions of NEAT1, miR-34a, SIRT1, and their associated hormonal and genetic pathways. Results indicated that NEAT1 was significantly downregulated in severe oligospermia patients, while its levels in non-obstructive azoospermia patients did not differ significantly from healthy controls. Furthermore, serum miR-34a expression was considerably upregulated in both patient groups compared to controls. This study highlights the promise of serum NEAT1 and miR-34a as diagnostic markers for non-obstructive azoospermia and severe oligospermia. These findings provide valuable insights into male infertility and indicate potential avenues for personalized treatment strategies.

Joint and individual associations between multiple vitamins and sperm quality in adult men

Background

Several studies have suggested that a healthy diet is associated with improved male fertility outcomes. However, the joint and individual associations between the status of multiple vitamins and sperm quality remain unclear.

Objectives

This study aimed to investigate the associations between serum vitamin levels and sperm quality parameters in adult men.

Methods

A cross-sectional study was conducted among 156 adult men seeking fertility care at a reproductive center from December 2023 to June 2024. Blood and semen were collected on the same day to determine the concentrations of nine kinds of vitamins (B1, B2, B6, B9, B12, C, A, D, E) and five parameters of sperm quality [total sperm number, sperm concentration, progressive motile sperm, morphologically normal rate, and DNA fragment index (DFI)]. The joint and individual associations between vitamin levels and sperm quality were analyzed using multiple linear regression and Bayesian kernel machine regression (BKMR) models.

Results

Increased tertiles of vitamin B1 and 1,25-dihydroxyvitamin D3 [1,25-(OH)2-D3] in serum were associated with higher sperm quality (all P for trends < 0.10). Compared with the lowest tertiles, the highest tertiles of vitamin B12 had β: 3.0 (95% CI: 0.8, 5.2) increasing in DFI, and vitamin A was negatively associated with progressive sperm motility (P for trends = 0.05). We generally found null results between multiple vitamin levels and the parameters of sperm quality in the BKMR models.

Discussion

These research findings imply that vitamins could have a dose-dependent dual effect on sperm quality. More specifically, the impact of vitamins varies according to their dosage levels and types. Personalized vitamin supplementation may be more effective than taking multivitamins in improving sperm quality.

Micronutrient-Antioxidant Therapy and Male Fertility Improvement During ART Cycles

Today, accumulating evidence highlights the impact of oxidative stress (OS) on semen quality. It is considered to be a key factor contributing to the decline in male fertility. OS is detected in 30-80% of men with infertility, highlighting its strong association with impaired reproductive function and with clinical outcomes following the use of assisted reproductive technologies. Spermatozoa are particularly vulnerable to oxidative damage due to their high content of polyunsaturated fatty acids (PUFAs) and limited antioxidant defense abilities. OS arises from an imbalance between the production of reactive oxygen species and the capacity to neutralize or repair their adverse effects. Evidence indicates that OS leads to lipid peroxidation, protein oxidation, mitochondrial dysfunction, and genomic instability. Micronutrient-antioxidant therapies can play a key role in infertility improvement by neutralizing free radicals and preventing cellular damage. Many different micronutrients, including L-carnitine, L-glutathione, coenzyme Q10, selenium, and zinc, as well as vitamins complexes, are proposed to improve sperm parameters and male fertility potential. This study aims to review the impact of antioxidant supplementation on semen parameters, including sperm volume, motility, concentration, morphology, genome integrity (maturity and fragmentation), and in vitro fertilization (IVF) outcomes. Antioxidant intake and a balanced lifestyle reduce oxidative stress and mitochondrial dysfunction, enhancing the spermatogenesis and spermiogenesis processes, improving sperm quality, and protecting DNA integrity.

The Impact of Parental Preconception Nutrition, Body Weight, and Exercise Habits on Offspring Health Outcomes: A Narrative Review

An increasing number of studies highlight the critical role of both maternal and paternal nutrition and body weight before conception in shaping offspring health. Traditionally, research has focused on maternal factors, particularly in utero exposures, as key determinants of chronic disease development. However, emerging evidence underscores the significant influence of paternal preconception health on offspring metabolic outcomes. While maternal health remains vital, with preconception nutrition playing a pivotal role in fetal development, paternal obesity and poor nutrition are linked to increased risks of metabolic disorders, including type 2 diabetes and cardiovascular disease in children. This narrative review aims to synthesize recent findings on the effects of both maternal and paternal preconception health, emphasizing the need for integrated early interventions. The literature search utilized PubMed, UNF One Search, and Google Scholar, focusing on RCTs; cohort, retrospective, and animal studies; and systematic reviews, excluding non-English and non-peer-reviewed articles. The findings of this review indicate that paternal effects are mediated by epigenetic changes in sperm, such as DNA methylation and non-coding RNA, which influence gene expression in offspring. Nutrient imbalances during preconception in both parents can lead to low birth weight and increased metabolic disease risk, while deficiencies in folic acid, iron, iodine, and vitamin D are linked to developmental disorders. Additionally, maternal obesity elevates the risk of chronic diseases in children. Future research should prioritize human studies to explore the influence of parental nutrition, body weight, and lifestyle on offspring health, ensuring findings are applicable across diverse populations. By addressing both maternal and paternal factors, healthcare providers can better reduce the prevalence of metabolic syndrome and its associated risks in future generations.

Collagen-based materials in male genitourinary diseases and tissue regeneration

Male genitourinary dysfunction causes serious physical or mental distress, such as infertility and psychological harm, which leads to impaired quality of life. Current conventional treatments involving drug therapy, surgical repair, and tissue grafting have a limited effect on recovering the function and fertility of the genitourinary organs. To address these limitations, various biomaterials have been explored, with collagen-based materials increasingly gaining attention for reconstructing the male genitourinary system due to their superior biocompatibility, biodegradability, low antigenicity, biomimetic 3D matrix characteristics, hemostatic efficacy, and tissue regeneration capabilities. This review covers the recent biomedical applications of collagen-based materials including treatment of erectile dysfunction, premature ejaculation, penile girth enlargement, prostate cancer, Peyronie's disease, chronic kidney disease, etc. Although there are relatively few clinical trials, the promising results of the existing studies on animal models reveal a bright future for collagen-based materials in the treatment of male genitourinary diseases.

Graphic Abstract

The Impact of Minerals on Female Fertility: A Systematic Review

Female fertility and reproductive system disorders are influenced by a complex interplay of biological, physiological, and environmental factors. Minerals have emerged as crucial yet often overlooked elements that impact fertility and the prevalence of reproductive system disorders.

BACKGROUND/OBJECTIVES

This review aims to provide a comprehensive overview of the multifaceted role of minerals in female fertility, focusing on key areas such as oocyte quality, ovulation, embryo development, oxidative stress, miscarriage, hormonal regulation, environmental exposure, and in-vitro fertilization (IVF) outcomes.

METHODS

A systematic review was conducted, focusing on randomized controlled trials (RCTs), prospective cohort studies, case-control studies, nested case-control, and observational studies examining mineral supplementation and nutrition in women planning pregnancy or utilizing assisted reproduction technologies (ARTs). Relevant literature was sourced from multiple electronic databases, including PubMed, Scopus, Google Scholar, Web of Science, and the Cochrane Library, using keywords related to minerals and female fertility. The quality of studies was assessed using the Newcastle-Ottawa Scale (NCO) for non-randomized studies and the Risk of Bias (RoB) tool for RCTs. This systematic review has been registered on PROSPERO (registration number is CDR 42024547656).

RESULTS

From an initial pool of 20,830 records, 39 articles met the inclusion criteria and were analyzed. The studies addressed various reproductive outcomes influenced by minerals: embryo development, oocyte quality, oxidative stress, miscarriage, hormonal regulation, IVF outcomes, environmental exposure, and minerals as biomarkers. The analysis revealed that minerals like selenium, zinc, and copper are essential for maintaining reproductive health, while exposure to toxic metals such as cadmium and lead is detrimental.

CONCLUSIONS

This review highlights the crucial role of both mineral supplementation and serum mineral status in female fertility. The findings provide key insights for clinicians to improve reproductive health through targeted mineral intake and monitoring. Further research is needed to refine guidelines for supplementation and serum levels in women with fertility issues.

Exploring the impact of lipid stress on sperm cytoskeleton: insights and prospects

The decline in male fertility correlates with the global rise in obesity and dyslipidaemia, representing significant public health challenges. High-fat diets induce metabolic alterations, including hypercholesterolaemia, hepatic steatosis and atherosclerosis, with detrimental effects on testicular function. Testicular tissue, critically dependent on lipids for steroidogenesis, is particularly vulnerable to these metabolic disruptions. Excessive lipid accumulation within the testes, including cholesterol, triglycerides and specific fatty acids, disrupts essential sperm production processes such as membrane formation, maturation, energy metabolism and cell signalling. This leads to apoptosis, impaired spermatogenesis, and abnormal sperm morphology and function, ultimately compromising male fertility. During spermiogenesis, round spermatids undergo extensive reorganization, including the formation of the acrosome, manchette and specialized filamentous structures, which are essential for defining the final sperm cell shape. In this Perspective, we examine the impact of high-fat diets on the cytoskeleton of spermatogenic cells and its consequences to identify the mechanisms underlying male infertility associated with dyslipidaemia. Understanding these processes may facilitate the development of therapeutic strategies, such as dietary interventions or natural product supplementation, that aim to address infertility in men with obesity and hypercholesterolaemia. The investigation of cytoskeleton response to lipid stress extends beyond male reproduction, offering insights with broader implications.

Minerals and the Menstrual Cycle: Impacts on Ovulation and Endometrial Health

The role of minerals in female fertility, particularly in relation to the menstrual cycle, presents a complex area of study that underscores the interplay between nutrition and reproductive health. This narrative review aims to elucidate the impacts of minerals on key aspects of the reproductive system: hormonal regulation, ovarian function and ovulation, endometrial health, and oxidative stress. Despite the attention given to specific micronutrients in relation to reproductive disorders, there is a noticeable absence of a comprehensive review focusing on the impact of minerals throughout the menstrual cycle on female fertility. This narrative review aims to address this gap by examining the influence of minerals on reproductive health. Each mineral's contribution is explored in detail to provide a clearer picture of its importance in supporting female fertility. This comprehensive analysis not only enhances our knowledge of reproductive health but also offers clinicians valuable insights into potential therapeutic strategies and the recommended intake of minerals to promote female reproductive well-being, considering the menstrual cycle. This review stands as the first to offer such a detailed examination of minerals in the context of the menstrual cycle, aiming to elevate the understanding of their critical role in female fertility and reproductive health.

Carvacrol showed a curative effect on reproductive toxicity caused by Bisphenol AF via antioxidant, anti-inflammatory and anti-apoptotic properties

Bisphenol AF (BPAF) is an endocrine disruptor, and human exposure to these chemicals is growing in industrialized nations. BPAF has been demonstrated in studies to have toxic effects on reproductive health. This study examined the effects of oral exposure to BPAF on the reproductive system and the protective effects of carvacrol in rats. From 32 Wistar albino rats, four separate groups were set up for this purpose. Carvacrol 75 mg/kg and BPAF 200 mg/kg were administered by oral gavage method. Rat sperm parameters and serum testosterone levels were measured after 28 days of administration. The study looked at the MDA in the testis tissues, as well as CAT, GPx, and GSH as antioxidants parameters, NF-κB and TNF-α as inflammatory markers, caspase-3 and Bcl-2 as apoptosis parameters, and PCNA as cell proliferation markers. In addition, testis tissues underwent histological evaluation. As a result, in rats exposed to only BPAF, sperm counts declined, testosterone levels reduced, oxidative stress, inflammation, and apoptosis increased, and cell proliferation decreased. Furthermore, severe disruptions in tissue architecture and decreased spermatogenesis were reported. In contrast, sperm parameters improved, testosterone levels increased, oxidative stress and inflammation decreased, and apoptosis was prevented in the carvacrol-treated group compared to the BPAF-only group. It was also found that spermatogenesis was maintained, and structural abnormalities in testicular tissue were mostly avoided with an increase in PCNA expression. According to the findings, despite BPAF-induced testicular and reproductive toxicity, carvacrol had therapeutic potential due to its anti-inflammatory, antioxidant, cell proliferation-increasing, and anti-apoptotic activities.