Dietary supplementation with docosahexaenoic acid (DHA) improves seminal antioxidant status and decreases sperm DNA fragmentation

Association of the serum metabolomic profile by nuclear magnetic resonance spectroscopy with sperm parameters: a cross-sectional study of 325 men

OBJECTIVE

To determine whether 155 circulating metabolic measures relevant to lifestyle and metabolic health are associated with sperm parameters, as measured by concentration, motility, and total motile sperm count (TMSC).

STUDY DESIGN

Cross sectional.

SETTING

University hospital.

PATIENT(S)

Three hundred twenty-five men prospectively recruited between April 1, 2017 and March 31, 2019.

INTERVENTION(S)

Detailed demographic, lifestyle, fertility, medical history, and semen analysis with quantification of nonfasting serum lipids, lipoprotein subclasses, and low-molecular weight metabolites (including amino acids, glycolysis, and inflammatory markers) by nuclear magnetic resonance (NMR) spectroscopy.

MAIN OUTCOME MEASURE(S)

Association of serum metabolic profiles with sperm parameters.

RESULT(S)

The age of the participants was mean 37.2 years, with a median sperm concentration of 35 million/mL and median motility of 53%. Of these men, 76% had a TMSC >15 million, 10% had 5-15 million, and 14% had <5 million. In both univariate and confounder adjusted analyses, an extensive range of lipids and lipoproteins, glycolysis-related metabolites, amino acids, ketone bodies, creatinine, or albumin showed no strong statistically significant association with sperm concentration, motility, or the odds of having a reduced or low TMSC. Higher levels of glycolysis metabolites and ketone bodies were associated with an increased odds of TMSC <15 million compared with ≥15 million (odds ratios of ∼1.2-1.3), and several lipids/lipoprotein concentrations appeared to protect against very low TMSC (<5 million compared with ≥5 million) with odds ratios of ∼0.8 or greater.

CONCLUSION(S)

Several metabolites exhibited potentially clinically relevant strength of association with the odds of a low TMSC and warrant replication.

Antarctic Krill Oil Attenuates Oxidative Stress via the KEAP1-NRF2 Signaling in Patients with Coronary Heart Disease

Background

Antarctic krill oil (AKO) has strong antioxidant activities and is effective for alleviating coronary heart disease (CHD). Kelch-like ECH-associated protein 1-NF-E2-related factor 2 (KEAP1-NRF2) axis is a crucial antioxidant signaling pathway. Thus, AKO may exert its antioxidant effects on CHD patients via KEAP1-NRF2 signaling.

Methods

AKO fatty acid (FA) profiles were analyzed by using gas chromatography (GC). One hundred CHD patients were divided into the intervention (IG, AKO) and control (CG, placebo) groups. Before and after 1, 2, and 3 months of intervention, we measured serum levels of reactive oxygen species (ROS), 8-hydroxy-2-deoxyguanosine (8-OHdG), nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione (GSH), and glutathione peroxidase (GPx), and KEAP1 and NRF2 levels in peripheral blood leukocytes (PBLs). Serum FAs were measured by GC at baseline and after 3-month intervention.

Results

AKO contains rich eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which is more than 27% of total FA. The levels of EPA and DHA, KEAP1, and NRF2 in the IG group were higher than those in the CG group (p < 0.05). Serum levels of ROS, 8-OHdG, NO, and MDA in the IG group were lower than those in the CG group, whereas the levels of SOD, GSH, and GPx in the IG group were higher than those in the CG group (p < 0.05). Serum levels of saturated fatty acids (UFA) in the IG group were higher than those in the CG group, whereas reverse results were obtained for the levels of saturated fatty acids (SFA). Serum levels of EPA and DHA had a strong negative relationship with the level of ROS, whereas the ROS level had a strong negative relationship with the levels of KEAP1-NRF2.

Conclusion

AKO increases antioxidant capacities of CHD patients via the KEAP1-NRF2 signaling in the PBL.

DHA from microalgae Schizochytrium spp. (Thraustochytriaceae) modifies the inflammatory response and gonadal lipid profile in domestic cats

The present study aimed to evaluate the inflammatory response, oxidative status and fatty acid deposition in reproductive tissues of cats supplemented with the dried microalgae Schizochytrium spp. (Thraustochytriaceae) as a DHA source. Thirty-seven cats (males, n 21; females, n 16; 11·5 (sd 0·5) months of age) were divided by sex into five groups. Treatment diets contained algae biomass at 4·0, 8·0, 12·0 or 16·0 g/kg replacing poultry fat (n-6 source). Cats were fed the respective diet for 62 d and neutered on day 58. Blood samples were collected at the beginning of the experiment (day 1), before neutering (day 58) and 4 d after surgery (day 62) for analysis of inflammation and oxidative markers. Acute-phase protein levels were altered (P < 0·01) in the postoperative period, without any treatment effect (P > 0·05). PGE2 concentrations after surgery were reduced linearly (R2 0·8706; P = 0·002) with microalgal inclusion. Blood platelet count was reduced (P = 0·001) after the surgery regardless treatment, but it was higher in the DHA group compared with control (P < 0·001). The DHA deposition (testicles, R2 0·846; ovaries, R2 0·869) and the n-6:n-3 ratio (testicles, R2 0·859; ovaries, R2 0·955) in gonads had a pattern which fitted a quadratic model. DHA from Schizochytrium spp. modifies PGE2 response after the surgery in cats. The physiological roles of the DHA in the reproduction of cats were not investigated, but its gonadal deposition after supplementation was observed.

Sperm DNA Fragmentation: A New Guideline for Clinicians

Sperm DNA integrity is crucial for fertilization and development of healthy offspring. The spermatozoon undergoes extensive molecular remodeling of its nucleus during later phases of spermatogenesis, which imparts compaction and protects the genetic content. Testicular (defective maturation and abortive apoptosis) and post-testicular (oxidative stress) mechanisms are implicated in the etiology of sperm DNA fragmentation (SDF), which affects both natural and assisted reproduction. Several clinical and environmental factors are known to negatively impact sperm DNA integrity. An increasing number of reports emphasizes the direct relationship between sperm DNA damage and male infertility. Currently, several assays are available to assess sperm DNA damage, however, routine assessment of SDF in clinical practice is not recommended by professional organizations. This article provides an overview of SDF types, origin and comparative analysis of various SDF assays while primarily focusing on the clinical indications of SDF testing. Importantly, we report four clinical cases where SDF testing had played a significant role in improving fertility outcome. In light of these clinical case reports and recent scientific evidence, this review provides expert recommendations on SDF testing and examines the advantages and drawbacks of the clinical utility of SDF testing using Strength-Weaknesses-Opportunities-Threats (SWOT) analysis.

Oxidative Stress in Chronic Liver Disease and Portal Hypertension: Potential of DHA as Nutraceutical

Chronic liver disease constitutes a growing public health issue worldwide, with no safe and effective enough treatment clinical scenarios. The present review provides an overview of the current knowledge regarding advanced chronic liver disease (ACLD), focusing on the major contributors of its pathophysiology: inflammation, oxidative stress, fibrosis and portal hypertension. We present the benefits of supplementation with docosahexaenoic acid triglycerides (TG-DHA) in other health areas as demonstrated experimentally, and explore its potential as a novel nutraceutical approach for the treatment of ACLD and portal hypertension based on published pre-clinical data.

Best laboratory practices and therapeutic interventions to reduce sperm DNA damage

Conventional semen analysis is considered the cornerstone investigation for infertile men. Nonetheless, this routine test does not provide information on important sperm functions like sperm DNA fragmentation (SDF). Abnormalities of human spermatozoal nucleus and chromatin have a detrimental impact on both natural and assisted reproductive outcomes. In vivo, SDF results from abnormalities in chromatin compaction, abortive apoptosis and oxidative stress, while in vitro, a number of factors may be implicated. Various SDF testing methods are available, and the most commonly utilised assays include terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL), sperm chromatin dispersion (SCD) test, sperm chromatin structure assay (SCSA) and Comet assay. SDF testing has shown beneficial effects on treatment decision-making; however, its routine use in the initial evaluation of infertile men is still not recommended. One of the treatment options to reduce sperm DNA damage is the use of antioxidants. Despite the documented improvement in semen parameters and sperm DNA integrity following antioxidant therapy, no definitive recommendation is reached due to lack of large, well-designed, randomised, placebo-controlled trials assessing their exact role in male factor infertility. The objectives of this review article are to illustrate the aetiologies of SDF, to describe the effects of SDF on male factor fertility, to explore the common techniques utilised in SDF testing, to review the clinical indications for SDF testing and to review the effect of antioxidant therapy as a method to alleviate SDF.

Mediterranean Diet as a Tool to Combat Inflammation and Chronic Diseases. An Overview

Since ancient times, the quality of nourishment is a milestone for the maintenance of health and as it is stated 'prevention is better than cure', amongst the so-called 'healthy' diets Mediterranean diet (MD) claims the lion's share. It stands in good stead because of a variety of valuable macro- and micronutrients. So, adherence to a MD is associated with the reduction of inflammation and non-communicable (NCD) OR chronic diseases. Numerous studies try to scrutinize the role of MD components as regards reducing inflammation, lowering rate, and mortality for disorders and illnesses, and preventing NCD. MD regime of the inhabitants of the Mediterranean basin includes a variety of ethnic nutritional habits and regulates an array of effects and epigenetic changes that affect human wellbeing. The research is still ongoing and endeavors to elucidate every aspect of this issue. This review focuses on the impact of MD on inflammation highlights positive results regarding NCD and indicates the need for more high-quality experiments and trials in order to overcome any discrepancies.

Biochemical profiling of three indigenous Dunaliella isolates with main focus on fatty acid composition towards potential biotechnological application

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Biochemical composition of native isolates determined their potential application.

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The isolates tend to store energy and carbon mainly in lipid, not carbohydrate, form.

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The fatty acid profile of the isolates show appropriate n3:n6 and health lipid indices.

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Dunaliella sp. ABRIINW-B1 and -G2/1 are the proper options for nutraceutical purposes.

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Dunaliella sp. ABRIINW-I1 well suits pharmaceutical and aquaculture application.

This study describes the biochemical composition of three isolates, Dunaliella sp. ABRIINW-B1, -G2/1 and -I1 towards the biotechnological potential. Dunaliella sp. ABRIINW- G2/1 and -I1 had a remarkable protein content (∼40% dry weight). Dunaliella sp. ABRIINW-I1 contained a pigment fraction of 3.2% largely composed of chlorophyll a (1.9%) and carotenoid (1.1%). Dunaliella sp. ABRIINW-B1, -G2/1 and -I1 produced respectively 42, 36 and 47% lipid content. The occurrence of high lipid and low carbohydrate (4–7%) in the isolates demonstrated their cell tendency to store energy and carbon mainly in lipid form. The lipid profile of the isolates expressed adequate n3:n6 ratio and health indices. The biochemical analysis revealed that Dunaliella sp. ABRIINW-B1 and -G2/1 have potential applications in the food and freshwater aquafeed sector. While Dunaliella sp. ABRIINW-I1 owing to appropriate pigment, protein, and lipid level containing very-long-chain polyunsaturated fatty acids showed a great promise in nutritional, pharmaceutical and marine aquafeed industries.

Oxidative Stress in Male Infertility: Causes, Effects in Assisted Reproductive Techniques, and Protective Support of Antioxidants

The spermatozoon is a highly specialized cell, whose main function is the transport of the intact male genetic material into the oocyte. During its formation and transit throughout male and female reproductive tracts, sperm cells are internally and externally surrounded by reactive oxygen species (ROS), which are produced from both endogenous and exogenous sources. While low amounts of ROS are known to be necessary for crucial physiological sperm processes, such as acrosome reaction and sperm-oocyte interaction, high levels of those species underlie misbalanced antioxidant-oxidant molecules, generating oxidative stress (OS), which is one of the most damaging factors that affect sperm function and lower male fertility potential. The present work starts by reviewing the different sources of oxidative stress that affect sperm cells, continues by summarizing the detrimental effects of OS on the male germline, and discusses previous studies addressing the consequences of these detrimental effects on natural pregnancy and assisted reproductive techniques effectiveness. The last section is focused on how antioxidants can counteract the effects of ROS and how sperm fertilizing ability may benefit from these agents.

Relevance of Fatty Acids to Sperm Maturation and Quality

Almost 50% of infertility cases are associated with human male infertility. The sperm membrane is a key structure influencing sperm morphology and function in normal and pathological conditions. The fatty acid profile determines the performance not only of sperm motility but also of acrosomal reaction and sperm-oocyte fusion. This review presents available knowledge on the role of fatty acid composition in human sperm and spermatogenesis and discusses the influence of dietary fatty acids on the sperm fatty acid profile. Recent studies in biological sciences and clinical researches in this field are also reported. The topic object of this review has potential application in medicine by identifying potential causes of infertility.

Associations of Fish Oil Supplement Use With Testicular Function in Young Men

IMPORTANCE

Many young men have poor semen quality, and the causes are often unknown. Supplement intake of ω-3 polyunsaturated fatty acid has been found to improve semen quality among men with infertility, but the association with semen quality among healthy men is unknown.

OBJECTIVE

To determine if intake of ω-3 fatty acid supplements is associated with testicular function as measured by semen quality and reproductive hormone levels among healthy men.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included young Danish men from the general population recruited between January 1, 2012, and December 31, 2017, at compulsory examinations to determine their fitness for military service. Young unselected men were approached after the examination and invited to participate in a study of reproductive function, regardless of their fitness for military service. Data analysis was conducted from September 1, 2018, to June 30, 2019.

EXPOSURES

Intake of supplements, including fish oil, during the past 3 months.

MAIN OUTCOMES AND MEASURES

Semen quality, measured as volume, concentration, total sperm count, percentage of morphologically normal spermatozoa, and motility, and serum reproductive hormone levels, measured as follicle-stimulating hormone, luteinizing hormone, testosterone, free testosterone, and inhibin B levels.

RESULTS

Among 1679 young Danish men (median [interquartile range] age, 18.9 [18.7-19.4] years) recruited to participate, 98 men (5.8%) reported use of fish oil supplements during the past 3 months, of whom 53 (54.1%) reported intake on 60 or more days. After adjustment and compared with men with no supplement intake, men with fish oil supplement intake on fewer than 60 days had semen volume that was 0.38 (95% CI, -0.03 to 0.80) mL higher, and men with fish oil supplement intake on 60 or more days had semen volume that was 0.64 (95% CI, 0.15 to 1.12) mL higher (P for trend < .001). Similarly, testicular size in men with supplement intake on fewer than 60 days was 0.8 (95% CI, -0.2 to 1.9) mL larger and in men with fish oil supplement intake on 60 or more days was 1.5 (95% CI, 0.2 to 2.8) mL larger compared with men with no supplement intake (P for trend = .007). After adjustment, men with fish oil supplement intake had a 20% (95% CI, 9%-31%) lower follicle-stimulating hormone level and 16% (95% CI, 8%-24%) lower luteinizing hormone level compared with men with no supplement intake. There were no associations of intake of other supplements with measures of testicular function.

CONCLUSIONS AND RELEVANCE

These findings suggest that intake of fish oil supplements was associated with better testicular function, which is less likely to be due to confounding by indication, as no associations of intake of other supplements with testicular function were found. This cross-sectional study did not examine the actual content of ω-3 fatty acids in the supplements; therefore, these findings need confirmation in well-designed randomized clinical trials among unselected men.

Dietary Cholesterol and Lipid Overload: Impact on Male Fertility

Lipid metabolic disorders due to poor eating habits are on the rise in both developed and developing countries, with a negative impact of the "Western diet" on sperm count and quality. Dietary lipid imbalance can involve cholesterol, fatty acids, or both, under different pathophysiological conditions grouped under the term dyslipidemia. The general feature of dyslipidemia is the development of systemic oxidative stress, a well-known deleterious factor for the quality of male gametes and associated with infertility. Sperm are particularly rich in polyunsaturated fatty acids (PUFA), an important characteristic associated with normal sperm physiology and reproductive outcomes, but also targets of choice for oxidative thrust. This review focuses on the effects of dietary cholesterol or different fatty acid overload on sperm composition and function in both animals and humans. The links between oxidative stress induced by dyslipidemia and sperm dysfunction are then discussed, including possible preventive or therapeutic strategies to preserve gamete quality, longevity when stored in cryobanking, and male fertility.

Incidence of high sperm DNA fragmentation in a targeted population of subfertile men

Sperm DNA integrity is important for fertility, however the incidence of high levels of DNA fragmentation (DNA fragmentation index (DFI) >30%) is not well described. In 2011, our clinics implemented guidelines for sperm DNA fragmentation (SDF) testing based on risk factors using the sperm chromatin structure assay (SCSA). The aim of this retrospective study is to characterise SDF and associated factors (age, semen parameters, smoking status and BMI) for sub-fertile males (n = 1082) and sperm donors (n = 234). The average DFI was 12.1 ± 9.8%. The distribution of men with low, moderate and high SDF (<15, 15-30 and >30%) was 74.8%, 19.4% and 5.8%, respectively. Men with high DFI were older (45 ± 9.5 vs 38 ± 6.7) and had lower percentage of motile sperm (38.8 ± 16.1% vs 55.3 ± 15.8%) than men with normal DFI. Over 17% of the men in the quartile with the highest age and lowest motility had a high DFI (>30%), compared to a high DFI rate of 2-4% for the other 3 quartiles. Repeat testing following lifestyle interventions was available for 29 couples where the men had high initial DFI (35 ± 9.5%). Of these men, 71.4% had a decrease of DFI into the moderate or low range. This study shows that SDF testing can be targeted based on age and sperm motility, thereby reducing unnecessary testing. Furthermore, we provide evidence that lifestyle modifications can reduce DNA fragmentation in men with high DFI.

Interventions to Prevent Sperm DNA Damage Effects on Reproduction

Excessive oxidation and antioxidant imbalance resulting from several conditions may cause sperm DNA damage, which, in turn, affect male fertility, both natural and assisted. Sperm DNA damage transferred to the embryo might also affect the health of offspring. Several conditions associated with excessive oxidative stress are modifiable by the use of specific treatments, lifestyle changes, and averting exposure to environmental/occupational toxicants. Here, we discuss the strategies to reduce sperm DNA damage with a focus on clinical and surgical interventions.

The influence of omega-3 fatty acids on semen quality markers: a systematic PRISMA review

BACKGROUND

Infertility affects about 15% of all couples worldwide. Male factors such as decreased semen quality contribute to around 40% of the cases. Recent reviews have shown that different foods and nutrients may improve semen quality.

OBJECTIVES

We conducted a systematic review in order to investigate whether intake of omega-3 fatty acids can improve semen quality markers.

MATERIALS AND METHODS

A systematic search of PubMed, Embase, and Cochrane was conducted in adherence with the PRISMA guideline from the earliest available online indexing year to October 2018. Keywords related to male fertility or infertility was combined with words describing omega-3 fatty acids and dietary fish intake. RCTs and observational studies on infertile and fertile men were included. Studies were considered eligible if they met the inclusion criteria, evaluated either the effect of omega-3 fatty acids or dietary fish intake and had semen quality as primary outcome.

RESULTS

Thousand and seventy four records were screened, and sixteen studies were ultimately included. Fourteen of the included studies found an improvement or association between omega-3 and at least one semen quality marker. As the studies were very inhomogeneous in participants (fertile/infertile, age, BMI, ethnicity etc), no meta-analysis was performed.

DISCUSSION

The findings in this review are limited by the few available RCTs. Furthermore, RCTs were very heterogenetic according to study population, sample size, dosage of omega-3, and durations of follow up. Results from the observational studies might have been affected by recall bias and confounded by lifestyle factors.

CONCLUSION

Based on the findings in this review, omega-3 supplements and dietary intake of omega-3 might improve semen quality parameters in infertile men and men from couples seeking fertility treatment. However, more research is required in order to fully clarify the effect of omega-3 on semen quality and research with fecundity as end point is needed.

Antioxidants for male subfertility

BACKGROUND

The inability to have children affects 10% to 15% of couples worldwide. A male factor is estimated to account for up to half of the infertility cases with between 25% to 87% of male subfertility considered to be due to the effect of oxidative stress. Oral supplementation with antioxidants is thought to improve sperm quality by reducing oxidative damage. Antioxidants are widely available and inexpensive when compared to other fertility treatments, however most antioxidants are uncontrolled by regulation and the evidence for their effectiveness is uncertain. We compared the benefits and risks of different antioxidants used for male subfertility. This review did not examine the use of antioxidants in normospermic men.

OBJECTIVES

To evaluate the effectiveness and safety of supplementary oral antioxidants in subfertile men.

SEARCH METHODS

The Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and two trials registers were searched on 1 February 2018, together with reference checking and contact with study authors and experts in the field to identify additional trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any type, dose or combination of oral antioxidant supplement with placebo, no treatment or treatment with another antioxidant, among subfertile men of a couple attending a reproductive clinic. We excluded studies comparing antioxidants with fertility drugs alone and studies that included fertile men attending a fertility clinic because of female partner infertility.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. The primary review outcome was live birth. Clinical pregnancy, adverse events and sperm parameters were secondary outcomes.

MAIN RESULTS

We included 61 studies with a total population of 6264 subfertile men, aged between 18 and 65 years, part of a couple who had been referred to a fertility clinic and some of whom were undergoing assisted reproductive techniques (ART). Investigators compared and combined 18 different oral antioxidants. The evidence was of 'low' to 'very low' quality: the main limitation was that out of the 44 included studies in the meta-analysis only 12 studies reported on live birth or clinical pregnancy. The evidence is current up to February 2018.Live birth: antioxidants may lead to increased live birth rates (OR 1.79, 95% CI 1.20 to 2.67, P = 0.005, 7 RCTs, 750 men, I2 = 40%, low-quality evidence). Results suggest that if in the studies contributing to the analysis of live birth rate, the baseline chance of live birth following placebo or no treatment is assumed to be 12%, the chance following the use of antioxidants is estimated to be between 14% and 26%. However, this result was based on only 124 live births from 750 couples in seven relatively small studies. When studies at high risk of bias were removed from the analysis, there was no evidence of increased live birth (Peto OR 1.38, 95% CI 0.89 to 2.16; participants = 540 men, 5 RCTs, P = 0.15, I2 = 0%).Clinical pregnancy rate: antioxidants may lead to increased clinical pregnancy rates (OR 2.97, 95% CI 1.91 to 4.63, P < 0.0001, 11 RCTs, 786 men, I2 = 0%, low-quality evidence) compared to placebo or no treatment. This suggests that if in the studies contributing to the analysis of clinical pregnancy, the baseline chance of clinical pregnancy following placebo or no treatment is assumed to be 7%, the chance following the use of antioxidants is estimated to be between 12% and 26%. This result was based on 105 clinical pregnancies from 786 couples in 11 small studies.Adverse eventsMiscarriage: only three studies reported on this outcome and the event rate was very low. There was no difference in miscarriage rate between the antioxidant and placebo or no treatment group (OR 1.74, 95% CI 0.40 to 7.60, P = 0.46, 3 RCTs, 247 men, I2 = 0%, very low-quality evidence). The findings suggest that in a population of subfertile men with an expected miscarriage rate of 2%, the chance following the use of an antioxidant would result in the risk of a miscarriage between 1% and 13%.Gastrointestinal: antioxidants may lead to an increase in mild gastrointestinal upsets when compared to placebo or no treatment (OR 2.51, 95% CI 1.25 to 5.03, P = 0.010, 11 RCTs, 948 men, I2 = 50%, very low-quality evidence). This suggests that if the chance of gastrointestinal upsets following placebo or no treatment is assumed to be 2%, the chance following the use of antioxidants is estimated to be between 2% and 9%. However, this result was based on a low event rate of 35 out of 948 men in 10 small or medium-sized studies, and the quality of the evidence was rated very low and was high in heterogeneity.We were unable to draw any conclusions from the antioxidant versus antioxidant comparison as insufficient studies compared the same interventions.

AUTHORS' CONCLUSIONS

In this review, there is low-quality evidence from seven small randomised controlled trials suggesting that antioxidant supplementation in subfertile males may improve live birth rates for couples attending fertility clinics. Low-quality evidence suggests that clinical pregnancy rates may also increase. Overall, there is no evidence of increased risk of miscarriage, however antioxidants may give more mild gastrointestinal upsets but the evidence is of very low quality. Subfertilte couples should be advised that overall, the current evidence is inconclusive based on serious risk of bias due to poor reporting of methods of randomisation, failure to report on the clinical outcomes live birth rate and clinical pregnancy, often unclear or even high attrition, and also imprecision due to often low event rates and small overall sample sizes. Further large well-designed randomised placebo-controlled trials reporting on pregnancy and live births are still required to clarify the exact role of antioxidants.

Adherence to the Mediterranean diet is positively associated with sperm motility: A cross-sectional analysis

The aim of this cross-sectional analysis is to investigate the associations between the adherence to the Mediterranean Diet (MD) and semen quality parameters. To assess the adherence to the MD, the Trichopoulou score was used. Semen parameters were assessed as described in the 2010 WHO's report and the results are showed across tertiles of MD adherence. A total of 106 participants were included. Compared to those in the lowest MD adherence tertile, participants in the top tertile had statistically significant higher BMI and waist circumference and consumed more energy, and also had statistically significant higher semen pH, and total sperm motility and progressive sperm motility percentages, and lower sperm immotility percentages. Moreover, percentage of total and progressive motility were significantly higher among those subjects in the higher adherence to MD in comparison with those in low-medium adherence category. The multivariable linear regression models evaluating the relationship between the sperm quality parameters and tertiles of MD adherence adjusted by age, energy and BMI showed that compared with the lowest tertile, men in the highest tertile had a higher percentage of total sperm motility [β non-standardized coefficient = 12.785]. These findings suggest that adherence to the MD was positively associated with sperm motility.

Docosahexaenoic acid in the treatment of male infertility

Literature review is devoted to the analysis of modern data on the use of docosahexaenoic acid in the treatment of male infertility. A brief description of modern ideas about the possible causes of male infertility (a disturbance of function of the cell membrane and genetic damage of sperm) was conducted. The data on the anti-inflammatory properties of omega-3 polyunsaturated fatty acids are described in detail. The bioavailability of docosahexaenoic acid and the choice of drugs containing it for the treatment of male infertility are discussed. Increasing the content of polyunsaturated fatty acids, in particular docosahexaenoic acid, in the sperm membrane was associated with higher ejaculate quality. Therapy with the use of these substances led to the improvement of standard indicators of semen and a decrease in the proportion of sperm with fragmented DNA.

The Effect of Nutrients and Dietary Supplements on Sperm Quality Parameters: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Infertility, which affects ∼15% of the world's population, is a global public health issue recognized by the WHO. Therefore, it is of major clinical and public health importance to investigate whether modifiable lifestyle factors-such as stress, drug use, smoking, alcohol intake, and diet-may influence human fertility. A systematic review and meta-analysis of randomized clinical trials (RCTs) from the MEDLINE-PubMed database was conducted to assess the effect of nutrients, dietary supplements, or food on sperm quality parameters. In total, 28 articles were included for qualitative analysis and 15 for quantitative meta-analysis. Total sperm concentrations [expressed as mean differences (MDs); 95% CIs, in spermatozoa (spz)/mL] were increased by selenium (3.91 × 106 spz/mL; 3.08, 4.73 spz/mL), zinc (1.48 × 106 spz/mL; 0.69, 2.27 spz/mL), omega-3 (n-3) fatty acids (10.98 × 106 spz/mL; 10.25, 11.72 spz/mL), and coenzyme Q10 (CoQ10) (5.93 × 106 spz/mL; 5.36, 6.51 spz/mL). Sperm counts were increased by ω-3 fatty acids (18.70 × 106 spz/mL; 16.89, 20.51 spz/mL) and CoQ10 supplementation (10.15 × 106 spz/mL; 8.34, 11.97 spz/mL). Sperm total motility was increased by selenium (3.30%; 2.95%, 3.65%), zinc (7.03%; 6.03%, 8.03%), ω-3 fatty acids (7.55%; 7.09%, 8.01%), CoQ10 (5.30%; 4.98%, 5.62%), and carnitines (7.84%; 6.54%, 9.13%), whereas sperm progressive motility was increased only after supplementation with carnitines (7.45%; 6.24%, 8.67%). Finally, sperm morphology was enhanced by selenium (1.87%; 1.50%, 2.24%), ω-3 fatty acid (0.91%; 0.69%, 1.13%), CoQ10 (1.06%; 0.72%, 1.41%), and carnitine (4.91%; 3.68%, 6.15%) supplementation. This meta-analysis of RCTs suggests that some dietary supplements could beneficially modulate sperm quality parameters and affect male fertility. However, results must be cautiously interpreted due to the limited sample size of the meta-analyzed studies and the considerable observed interstudy heterogeneity.The present study and the corresponding search protocol were registered at the PROSPERO registry at http://www.crd.york.ac.uk/PROSPERO as CRD42017058380.

Effect of nut consumption on semen quality and functionality in healthy men consuming a Western-style diet: a randomized controlled trial

BACKGROUND

Human semen quality has declined in industrialized countries. Pollution, smoking, and the consumption of a Western-style diet are all hypothesized as potential causes.

OBJECTIVE

We evaluated the effect of chronic consumption of nuts on changes in conventional semen parameters and the potential mechanisms implicated.

DESIGN

The FERTINUTS study was a 14-wk randomized, controlled, parallel trial. A total of 119 healthy men, aged 18-35 y, were allocated to 1 of 2 intervention groups: one group was fed the usual Western-style diet enriched with 60 g of a mixture of nuts/d (nut group), and the other was fed the usual Western-style diet avoiding nuts (control group). Semen and blood samples were collected at baseline and at the end of the intervention. Dietary information was recorded throughout the trial. Changes in conventional semen parameters (pH, volume, sperm count and concentration, motility, and morphology) were determined as primary outcomes. The effect of nut consumption on sperm DNA fragmentation (SDF), reactive oxygen species (ROS) production, chromosome anomalies (X, Y, and 18), total DNA methylation, and microRNA expression were measured in sperm samples as potential causes of the changes in the seminogram.

RESULTS

Compared with the control group, improvements in total sperm count (P = 0.002) and vitality (P = 0.003), total motility (P = 0.006), progressive motility (P = 0.036), and morphology of sperm (P = 0.008) were observed in the nut group. Participants in the nut group showed an increase in the consumption of total fat, monounsaturated fatty acids, polyunsaturated fatty acids, magnesium, vitamin E, α-linolenic acid, total omega-3 (n-3) and ω-3:ω-6 ratio intake during the intervention. Participants in the nut group showed a significant reduction in SDF (P < 0.001) and in the expression of hsa-miR-34b-3p (P = 0.036). No significant changes in ROS, sperm chromosome anomalies, or DNA methylation were observed between groups.

CONCLUSIONS

The inclusion of nuts in a Western-style diet significantly improves the total sperm count and the vitality, motility, and morphology of the sperm. These findings could be partly explained by a reduction in the sperm DNA fragmentation. This trial was registered at ISRCTN as ISRCTN12857940.

Incubation of human sperm with micelles made from glycerophospholipid mixtures increases sperm motility and resistance to oxidative stress

Membrane integrity is essential in maintaining sperm viability, signaling, and motility, which are essential for fertilization. Sperm are highly susceptible to oxidative stress, as they are rich in sensitive polyunsaturated fatty acids (PUFA), and are unable to synthesize and repair many essential membrane constituents. Because of this, sperm cellular membranes are important targets of this process. Membrane Lipid Replacement (MLR) with glycerophospholipid mixtures (GPL) has been shown to ameliorate oxidative stress in cells, restore their cellular membranes, and prevent loss of function. Therefore, we tested the effects of MLR on sperm by tracking and monitoring GPL incorporation into their membrane systems and studying their effects on sperm motility and viability under different experimental conditions. Incubation of sperm with mixtures of exogenous, unoxidized GPL results in their incorporation into sperm membranes, as shown by the use of fluorescent dyes attached to GPL. The percent overall (total) sperm motility was increased from 52±2.5% to 68±1.34% after adding GPL to the incubation media, and overall sperm motility was recovered from 7±2% after H2O2 treatment to 58±2.5%)(n = 8, p<0.01) by the incorporation of GPL into sperm membranes. When sperm were exposed to H2O2, the mitochondrial inner membrane potential (MIMP), monitored using the MIMP tracker dye JC-1 in flow cytometry, diminished, whereas the addition of GPL prevented the decrease in MIMP. Confocal microscopy with Rhodamine-123 and JC-1 confirmed the mitochondrial localization of the dyes. We conclude that incubation of human sperm with glycerolphospholipids into the membranes of sperm improves sperm viability, motility, and resistance to oxidizing agents like H2O2. This suggests that human sperm might be useful to test innovative new treatments like MLR, since such treatments could improve fertility when it is adversely affected by increased oxidative stress.

Role of sperm DNA fragmentation in male factor infertility: A systematic review

OBJECTIVE

To summarise the latest evidence on the role of sperm DNA fragmentation (SDF) in male factor infertility, as SDF has been emerging as a valuable tool for male infertility evaluation.

METHODS

A search of PubMed was conducted using the keywords 'sperm DNA fragmentation' and 'male infertility'. Studies in languages other than English were excluded. All identified studies were screened and clinical studies in humans were included.

RESULTS

In all, 150 articles were included for analysis. Current evidence supports the association between high SDF and poor reproductive outcomes for natural conception and intrauterine insemination. Although the relationship between high SDF and in vitro fertilisation and intracytoplasmic sperm injection is less clear, the negative implication of high SDF on pregnancy loss is evident. Various treatment strategies have been attempted with varying success. The predictive value of SDF testing on outcomes of natural pregnancy and assisted reproduction illustrates its value in clinical practice.

CONCLUSION

The significant role of SDF in male factor infertility is supported by current evidence. The beneficial role of SDF testing in selection of varicocelectomy candidates, evaluation of patients with unexplained infertility and recurrent pregnancy loss, selection of the most appropriate assisted reproductive technique with highest success rate for infertile couples, and assessment of infertile men with modifiable lifestyle factors or gonadotoxin exposure has been recently proposed.

A Strengths-Weaknesses-Opportunities-Threats (SWOT) analysis on the clinical utility of sperm DNA fragmentation testing in specific male infertility scenarios

Background

Sperm DNA fragmentation (SDF) is recognized as a leading cause of male infertility because it can impair the paternal genome through distinct pathophysiological mechanisms. Current evidence supports SDF as a major factor in the pathophysiology of several conditions, including varicocele, unexplained infertility, assisted reproductive technology failure, and environmental lifestyle factors, although the mechanisms involved have not been fully described yet. Measurement of the levels of DNA fragmentation in semen provides valuable information on the integrity of paternal chromatin and may guide therapeutic strategies. A recently published clinical practice guideline (CPG) highlighted how to use the information provided by SDF testing in daily practice, which triggered a series of commentaries by leading infertility experts. These commentaries contained an abundance of information and conflicting views about the clinical utility of SDF testing, which underline the complex nature of SDF.

Methods

A search of papers published in response to the CPG entitled “Clinical utility of sperm DNA fragmentation testing: practice recommendations based on clinical scenarios” was performed within the Translational Andrology and Urology (TAU) website (http://tau.amegroups.com/). The start and end dates for the search were May 2017 and August 2017, respectively. Each commentary meeting our inclusion criteria was rated as “supportive without reservation”, “supportive with reservation”, “not supportive” or “neutral”. We recorded whether articles discussed either SDF characteristics as a laboratory test method or clinical scenarios, or both. Subsequently, we extracted the particulars from each commentary and utilized the ‘Strengths-Weaknesses-Opportunities-Threats’ (SWOT) analysis to understand the perceived advantages and drawbacks of SDF as a specialized sperm function method in clinical practice.

Results

Fifty-eight fertility experts from six continents and twenty-two countries contributed commentaries. Overall, participants (87.9%; n=51) were supportive of the recommendations provided by the CPG on the utility of SDF testing based on clinical scenarios. The majority of participants made explicit remarks about both the clinical scenarios and SDF assays’ characteristics. Among ‘not supportive’ and ‘supportive with reservation’ participants, 75% (n=30/40) and 77.5% (n=31/40) expressed concerns related to technical limitations of SDF testing methods and clinical utility of the test in one or more clinical scenarios discussed in the CPG, respectively. The SWOT analysis revealed that the CPG provides a reasonable evidence-based proposal for integration of SDF testing in the routine daily practice. It also uncovered gaps of knowledge and threats limiting the widespread application of SDF in everyday practice, thus allowing the identification of opportunities to further refine SDF testing and its clinical utility.

Conclusions

The understanding of the role of SDF in male infertility requires an in-depth analysis of the multifactorial pathophysiological processes and the theories involved. The SWOT analysis allowed an objective evaluation of CPG on the clinical utility of SDF testing based on clinical scenarios and its accompanying commentaries written by global experts in all possible angles. Implementation of SDF testing in the clinic may not only increase the outcome of ART but more importantly improve the health of both fathers to be and resulting offspring.

Effects of in Utero PFOS Exposure on Transcriptome, Lipidome, and Function of Mouse Testis

Transcriptomic and LC-MS/MS-based targeted lipidomic analyses were conducted to identify the effects of in utero PFOS exposure on neonatal testes and its relation to testicular dysfunction in adult offspring. Pregnant mice were orally administered 0.3 and 3 μg PFOS/g body weight until term. Neonatal testes (P1) were collected for the detection of PFOS, and were subjected to omics study. Integrated pathway analyses using DAVID, KEGG, and IPA underlined the effects of PFOS exposure on lipid metabolism, oxidative stress and cell junction signaling in testes. LC-MS/MS analysis showed that the levels of adrenic acid and docosahexaenoic acid (DHA) in testes were significantly reduced in the PFOS treatment groups. A significant linear decreasing trend in eicosapentaenoic acid and DHA with PFOS concentrations was observed. Moreover, LOX-mediated 5-hydroxyeicosatetraenoic acids (HETE) and 15-HETE from arachidonic acid in the testes were significantly elevated and a linear increasing trend of 15-HETE concentrations was detected with doses of PFOS. The perturbations of lipid mediators suggested that PFOS has potential negative impacts on testicular functions. Postnatal analysis of male offspring at P63 showed significant reductions in serum testosterone and epididymal sperm count. This study sheds light into the as yet unrevealed action of PFOS on lipid mediators in affecting testicular functions.