Human reproduction (Oxford, England)2026n = 1482
CohortHuman
This study looked at whether eating ultra-processed food around the time of conception affects fertility and early embryo development in couples. It followed 831 women and 651 men from before…
Human reproduction (Oxford, England)2026n = 1,220
CohortHuman
Researchers followed 1,220 men at a Utah fertility clinic and matched the outdoor heat and humidity each man lived through while his sperm were forming against a molecular measure of…
Human reproduction update2026n = 32 studies included
Meta AnalysisHuman
This study set out to review how different weight loss methods affect male fertility in men with obesity. It looked at 32 studies that compared lifestyle changes, medications, and bariatric…
Cureus2026n = 10 studies met inclusion criteria
Systematic ReviewHuman
This study set out to evaluate whether botulinum toxin injections near the scrotum or testicles affect male fertility. It reviewed animal studies and human case reports, focusing on outcomes like…
Translational andrology and urology2026
Narrative ReviewHuman
This review looked at whether the underwear a man wears, tight versus loose, actually affects his fertility. The testicles work best a little cooler than the rest of the body,…
Biomedicines2026
Narrative ReviewHuman
This review looked at how psychological stress might affect male fertility through oxidative stress. It synthesized animal studies and human observational data to explore the link between stress, oxidative damage,…
Asian journal of andrology2026n = 43 studies included
Systematic ReviewHuman
This umbrella review (a review of other reviews) set out to catalogue what damages male fertility. It gathered 43 systematic reviews and meta-analyses published between 2000 and 2025, covering 67…
Cureus2026n = 100
Cross SectionalHuman
This study looked at how different measures of obesity relate to semen quality in men from infertile couples who had no other known fertility risks. It compared body mass index…
Reproductive biology and endocrinology : RB&E2026n = 1,316 men (434 inactive, 430 low-activity, 452 moderate-activity)
CohortHuman
This study looked at whether the intensity of physical activity affects semen quality in men who already have impaired sperm health. It followed over 1,300 men undergoing fertility evaluations, each…
Archives of medical research2026n = 3,302
Cross SectionalHuman
This study set out to explore how coffee, exercise, and sleep relate to semen quality in men. It surveyed 3,302 men aged 18-60, collecting semen samples and lifestyle data through…
Translational andrology and urology2026n = 82 publications included
Narrative ReviewHuman
This review set out to explore how environmental factors affect sperm quality and male fertility. It analyzed 82 recent studies, mostly from 2020 onward, looking at pollutants, heat, radiation, and…
Environmental pollution (Barking, Essex : 1987)2026n = 4,847 semen examinations
CohortHuman
This study set out to examine how exposure to fine particulate air pollution (PM2.5) and its components affects semen quality, and whether living near green spaces might help protect against…
Asian journal of andrology2026n = 3336
Cross SectionalHuman
This study set out to examine how modifiable lifestyle factors like smoking, drinking, and weight affect semen quality in men. It analyzed data from over 3,300 men visiting a fertility…
The journal of sexual medicine2026n = 639 men across 10 studies
Systematic ReviewHuman
This systematic review set out to assess how GLP-1 receptor agonists (a class of diabetes and weight-loss drugs) affect male reproductive hormones, semen quality, and metabolic health. It pooled data…
Cureus2026n = 4,389 eligible out of 4,601 screened
Cross SectionalHuman
This study set out to see if taking oral medications or zinc supplements affects zinc levels in the blood and whether that links to better sperm health or fertility outcomes…
Frontiers in microbiology2026n = 80 semen samples
Cross SectionalHuman
This study set out to explore whether the mix of bacteria in semen differs between men with normal and abnormal sperm counts. Researchers analyzed semen samples from 80 Greek men,…
Scientific reports2026n = 98
Cross SectionalHuman
This study set out to understand how folic acid affects sperm health, especially in the context of inflammation in the reproductive tract. It looked at 98 men, measuring their red…
Arab journal of urology2026n = 200 initially, 174 completed follow-up
RCTHuman
This study tested whether CoQ10, L-carnitine (an amino-acid-like nutrient the body uses to turn fat into energy), or both together improve semen quality in men with low sperm count, poor…
Scientific reports2026
Meta AnalysisHuman
This study set out to examine whether astaxanthin (a potent antioxidant) could improve sperm quality after freezing and thawing. It pooled data from multiple studies to see how astaxanthin affected…
BMJ open2026n = 820
Case ControlHuman
This study looked at whether ozone (a reactive gas in smog, formed when pollution meets sunlight) affects semen quality in lower-income men with unhealthy lifestyle habits (think smoking, heavy drinking,…
Reproductive biomedicine online2026n = 324
Cross SectionalHuman
This study set out to see if physical fitness is linked to semen quality in Spanish men. Researchers analyzed semen samples from 324 men without known fertility issues, comparing self-reported…
PloS one2026n = 221
CohortHuman
This study set out to understand how lifestyle factors relate to semen abnormalities in men undergoing fertility evaluation in Ghana. It analyzed medical records of 221 men at a Ghanaian…
Genes & nutrition2026n = 300
Case ControlHuman
This study looked at whether the quality and amount of carbohydrates in a man's diet affect sperm DNA damage, a common problem in unexplained infertility. Researchers compared 300 Iranian men…
Scientific reports2026n = 156
Cross SectionalHuman
This study aimed to assess how much adult men know about male fertility, focusing on medical and lifestyle factors that affect it. Researchers surveyed 156 men of reproductive age using…
Toxicology reports2026
Narrative ReviewHuman
This review set out to examine how microplastics (tiny plastic particles) affect the male reproductive system at the cellular and molecular level. It compiled findings from multiple studies across scientific…
American journal of men's health2026n = 485
Cross SectionalHuman
This study looked at how occupational heat exposure and fertility-related stress might affect semen quality. It compared 485 men, split into groups with normal and low semen quality based on…
Frontiers in public health2026n = 5,114
CohortHuman
This study measured how outdoor temperature tracks with semen quality, using records from 5,114 men attending a reproductive medicine centre in Wenzhou, on China's east coast. The measure it used…
Reproductive biology and endocrinology : RB&E2026n = 15,581 men (10,670 in Denmark, 4,911 in Florida)
CohortHuman
This study set out to see if sperm quality changes with the seasons in Denmark and Florida, and whether outdoor temperatures play a role. It looked at semen samples from…
Reproductive biology and endocrinology : RB&E2026n = 38 studies
Systematic ReviewHuman
This systematic review set out to examine how phthalates, chemicals widely used to soften plastics and to carry fragrance in cosmetics, affect male fertility by altering semen quality. It pulled…
Journal of personalized medicine2026
Narrative ReviewHuman
This review examined how oxidative stress, sperm DNA damage, and epigenetic changes interact to affect male fertility. It pulled together studies on men with infertility, looking at how these factors…
Archivos espanoles de urologia2025n = 945 subjects
Meta AnalysisHuman
This study looked at whether vitamin D3 supplementation improves hormone levels and semen quality in infertile men. It pooled data from six randomized controlled trials involving 945 men, measuring changes…
Human reproduction open2025n = 223
Cross SectionalHuman
This study looked at whether a heart-healthy lifestyle is linked to better sperm quality in young men, using the American Heart Association's Life's Essential 8 score. That score rates eight…
Current issues in molecular biology2025
Narrative ReviewHuman
This review set out to examine how heavy metals like lead, mercury, and cadmium affect sperm quality and male fertility, focusing on their role in oxidative stress and antioxidant imbalance.…
Arab journal of urology2025
Narrative ReviewHuman
This narrative review set out to explore how lifestyle choices affect male fertility, examining diet, exercise, stress, sleep, weight, and environmental exposures. It synthesized existing research on how these factors…
Andrology2025n = 200
Cross SectionalHuman
This study looked at how eating patterns relate to sperm quality in healthy young men. Researchers scored the diets of 200 men against several patterns, healthy ones like the Mediterranean…
Reproductive biology and endocrinology : RB&E2025n = 2,430
Cross SectionalHuman
This study looked at whether obesity speeds up the decline in sperm quality that has been seen over time. Researchers reviewed semen tests from 2,430 men with normal sperm counts…
Journal of dietary supplements2025
Narrative ReviewHuman
This review set out to explore how dietary fatty acids (FAs) affect sperm quality and male fertility. It looked at recent studies on how different FAs influence sperm production and…
Reproductive biology and endocrinology : RB&E2025n = 1,349
Cross SectionalHuman
This study set out to see how often men ejaculate affects their sperm health, focusing on DNA damage and other semen measures. It looked at 1,349 men visiting a fertility…
Antioxidants (Basel, Switzerland)2025
Narrative ReviewHuman
This review looked at how oxidative stress (cell damage from unstable molecules called reactive oxygen species, a normal byproduct of metabolism that turns harmful when it outpaces the body's defenses)…
Frontiers in endocrinology2025n = 8,443 men (3,467 normal BMI, 3,444 overweight, 1,532 obese)
Meta AnalysisHuman
This meta-analysis (a study that statistically pools many earlier studies) looked at how body mass index (BMI, a weight-for-height number used to flag over- or under-weight) relates to sperm quality…
Oncoscience2025n = 278
Cross SectionalHuman
This study looked at how lifestyle and hormones affect semen quality and sperm DNA health in men. It examined 278 Indian men aged 21 to 50, measuring sperm count, movement,…
Nutrients2025n = 50 studies included
Meta AnalysisHuman
This systematic review and meta-analysis set out to see whether dietary supplements improve male fertility. It pooled 50 randomised trials in which men took a supplement for at least 12…
Arab journal of urology2025
Narrative ReviewHuman
This review set out to examine whether mobile phones and laptops, as sources of electromagnetic radiation and heat, might harm male fertility by affecting semen quality. It analyzed existing studies,…
Nutrients2025n = 358
Cross SectionalHuman
This study looked at how diet relates to sperm quality, comparing the Mediterranean diet, which is built on seasonal, fresh and whole foods, against ultra-processed foods, which are high in…
Frontiers in endocrinology2025n = 2,672 semen samples
CohortHuman
This study asked whether the pandemic changed how sensitive sperm production is to weather. It took 2,672 semen analyses from 1,287 Korean men collected between 2018 and 2024 and matched…
Advances in nutrition (Bethesda, Md.)2025n = 2,558 individuals across 11 studies
Meta AnalysisHuman
This study set out to see if sticking to a Mediterranean diet (MedDiet) is linked to better sperm quality and fertility outcomes in men. It pooled data from 11 studies,…
Current opinion in urology2025
Narrative ReviewHuman
This review gathers recent evidence on what damages male fertility and how much of it can be undone. Smoking raises sperm DNA fragmentation (breaks in the genetic material inside sperm)…
Reproductive biology and endocrinology : RB&E2025n = 18 peer-reviewed articles
Scoping ReviewHuman
This scoping review set out to map the evidence on how psychosocial work factors affect male fertility and sperm quality. It analyzed 18 peer-reviewed studies from 1990 to 2024, focusing…
BMC public health2025n = 1,180
Cross SectionalHuman
This study looked at whether exposure to air pollution, especially fine particles (PM2.5 and PM10), affects semen quality in men. It included 1,180 men aged 18, 45 from Foshan, China,…
Human reproduction update2024n = 37 total studies
Systematic ReviewHuman
This scoping review aimed to assess how diet before conception affects male fertility and reproductive outcomes. It analyzed 37 studies, including one randomized controlled trial and 36 observational studies, published…
Frontiers in pharmacology2024n = 877 (462 CoQ10-treated, 415 untreated/placebo-treated)
Meta AnalysisHuman
This systematic review and meta-analysis set out to assess whether coenzyme Q10 (CoQ10) supplementation improves semen quality and male hormone levels. It pooled data from eight randomized controlled trials involving…
Frontiers in nutrition2024n = 2032 men
Systematic ReviewHuman
This systematic review set out to assess whether following a Mediterranean diet affects sperm quality in men of reproductive age. It analyzed 10 studies involving over 2,000 men aged 18-55,…
Journal of clinical medicine2024
Narrative ReviewHuman
This narrative review argues that a man's fertility is a readable signal of his health generally, not just of his ability to father a child. The reasoning runs like this:…
Journal of clinical medicine2024n = 73
Cross SectionalHuman
This study set out to see how lifestyle and insulin resistance relate to male fertility. Insulin resistance means the body has stopped responding properly to insulin, so it takes more…
European journal of obstetrics, gynecology, and reproductive biology2024n = 274
Cross SectionalHuman
This study looked at whether following a Mediterranean diet is linked to better semen quality in men visiting fertility clinics. It compared semen parameters across 274 men grouped by how…
Nutrients2023n = 300
Cross SectionalHuman
This study looked at whether following a Mediterranean diet (MD) is linked to healthier sperm in men. Researchers surveyed 300 men (average age 35) visiting a reproductive medicine center, using…
Reproductive biology and endocrinology : RB&E2018
Narrative ReviewHuman
This review pulled together what is known about how everyday life affects a man's fertility, covering age, psychological stress, nutrition, physical activity, caffeine, scrotal temperature, hot water and mobile phone…
Basic and clinical andrology2017
Narrative ReviewHuman
This is a history of forty years of French research into male contraception (hormonal, chemical and thermal) summarising clinical trials involving thousands of men and couples. Those trials established that…