Lewin A, Lavon H.
Mol Aspects Med 1997;18:S213‐219.
This study looked at the effects of CoQ10 on sperm movement in IVF with intracytoplasmic sperm injection (ICSI). Semen samples were divided into 4 equal parts and incubated for 24 hours with four different media, including one supplemented with CoQ10. After incubation with CoQ10, a significant increase in sperm motility was observed in the sperm from asthenospermic men. In addition, patients with initial low fertilization rates after ICSI who were supplemented with oral CoQ1o 60 mg per day for a mean of 103 days. These patients demonstrated a significant improvement in fertilization rates after CoQ10 supplementaiton, from 10.3% to 26.3%.
Abad C, Amengual MJ, Gosalvez J, Coward K, Hannaoui N, Benet J, Garcia‐Peiro A, Prats J.
Andrologia 2012 [epub ahead of print].
In this study, sperm samples of 20 infertile patients with asthernoteratozoospermia were analyzed after the administration of an oral antioxidant treatment of l-Carnitine, vitamin C, CoQ10, vitamin E, zinc, vitamin B9 and B12, and selenium, over a 3 month period. DNA-degraded sperm decreased while DNA integrity improved, confirming that antioxidants could improve assisted reproductive technology’s outcomes.
Int Urol Nephrol 2012;44(3):689‐700.
This study evaluated the possible effects of CoQ10 supplementation on semen parameters and partner pregnancy rates. 287 participants underwent a CoQ10 treatment of 600 mg/day for 12 months. Sperm concentration, sperm motility and sperm morphology improved significantly, with positive effects on partner pregnancy rate, which was observed at 34.1%.
Nadjarzadeh A, Shidfar F, Amirjannati N, Vafa MR, MOtevalian SA, Gohari MR, Nazeri Kakhki SA, Akhondi MM, Sadeghi MR.
Andrologia 2013 [epub ahead of print].
This randomized, placebo-controlled trial examined the relationship between CoQ10 supplementation and antioxidant enzyme activity in seminal plasma. Sixty infertile men with idiopathic oligoasthenoteratozoospermia received 200 mg per day of CoQ10 or placebo for 3 months. Semen analyses conducted before and after treatment revealed that both CoQ10 levels and antioxidant enzyme activity markers increased in the CoQ10 group, suggesting that a 3-month supplementation with CoQ10 may reduce oxidative stress in semen plasma and improve semen parameters.
Balercia G, Buldreghini E, Vignini A, Tiano L, Paggi F, Amoroso S, Ricciardo‐Lamonica G, Boscaro M, Lenzi A, Littarru G.
Fertil Steril 2009;91(5):1785‐1792.
This double-blind randomized trial enlisted 55 interfile patients between 27 and 39 years and administered 200 mg of CoQ10 or placebo per day for 6 months. Both CoQ10 and ubiquinol levels increased significantly in seminal plasma and sperm cells after CoQ10 treatment, as well as sperm motility. Patients with lower baseline value for motility and CoQ10 levels showed a higher probability of responding to CoQ10 supplementation.
Safarinejad MR, Safarinejad S, Shafiei N, Safarinejad S.
J Urol 2012;188(2):526‐531.
This study used 200 mg of ubiquinol (reduced form of CoQ10) and placebo over a 26 week period in 228 men with unexplained fertility, to assess CoQ10 administration’s effects semen quality. After the ubiquinol treatment, sperm morphology, sperm density, and sperm motility were improved, leading the authors to conclude that ubiquinol is an effective treatment for men with unexplained oligoasthenoteratozoospermia.
The study evaluated the efficacy of CoQ10 supplementation on sperm parameters, sperm function and reproductive hormone profiles in infertile men. 300 mg of CoQ10 or placebo was administered to 212 infertile men over a 26-week period, followed by a 30-week treatment-free period. During both timeframes, semen analyses were conducted on various sperm parameters. The results showed an improvement in sperm density, count, morphology and motility with CoQ10 treatment.
Mancini A, De Marinis L, Littarru GP, Balercia G.
J Androl 1994;15(6):591‐594.
This study aimed to investigate the CoQ10 and quinone concentrations in seminal fluid and sperm cells after CoQ10 administration in infertile men. After CoQ10 administration, asthenozoospermic infertile men showed increased amounts of CoQ10 in both seminal plasma and sperm cells, ultimately improving sperm movement. Based on the strong correlation between CoQ10 concentration and sperm motility, the study suggested a cause/effect relationship between CoQ10 administration and improvements in sperm parameters.
Mancini A, De Marinis L, Oradei A, Hallgass ME, Conte G, Pozza D, Littarru GP.
J Androl 1994;15(6):591‐594.
In this study, 77 subjects underwent a semen analysis looking at seminal fluid and/or seminal plasma. A significant correlation was found between CoQ10 concentration and sperm count and sperm motility. Patients with varicocele, however, did not demonstrate the same correlation between CoQ10 concentration and sperm motility. The authors hypothesized a distinct CoQ10-related pathophysiology for varicocele patients. The study suggested a possible treatment with exogenous CoQ10 supplementation for patients with sperm problems.
Pignatti C, Cocchi M, Weiss H.
Biochem Exp Biol 1980;16:39‐42.
Examining the CoQ10 levels in rat hearts at different ages, this study showed that CoQ10 levels decline by about 20-30% with aging.
Nakada K, Sato A, Yoshida K, Morita T, Tanaka H, Inoue S, Yonekawa H, Hayashi J.
Proc Natl Acad Sci USA 2006;103:15148‐15153.
About half of infertility cases can be attributed to men due to mitochondrial genome mutations. This in-vivo mice study evaluated the possibility that mitochondrial respiration defects contribute to male infertility. Using wild type mice and those with mutant mtDNA, the study demonstrated that mitochondrial respiration defects, caused by accumulation of mtDNA damages, induced oligospermia and asthenozoospermia in the mice with mutant mtDNA, with most of their sperm carrying abnormalities in the middle piece and nucleus. The study concluded that normal mitochondrial function is necessary for healthy mammalian spermatogenesis.
Agarwal A, Saleh R, Bedaiwy M.
Fertil Steril 2003:79;829‐843.
This literature review summarizes the roles that reactive oxygen species (ROS) plays in both male and female reproduction and fertility in relation to IVF, embryo toxicity and development. In the male fertility context, ROS is known to compromise the fluidity of the sperm plasma membrane and the integrity of DNA in the sperm nucleus. In the female fertility context, ROS has been implicated in endometriosis and unexplained infertility. Combined with their negative effects on female fertility, high levels of ROS are detrimental to fertility potential, both in natural and assisted conceptions.
Sheweita SA, Tilmisany AM, Al‐Sawaf H.
Curr Drug Metab 2005;6(5):495‐501.
This review of antioxidants and male infertility suggested that identification of environmental and occupational risk factors to male infertility is needed, and proposed that a multi-faceted treatment approach involving supplementation with various antioxidants with proven efficacy, such as vitamin C, vitamin E and CoQ10, may improve male fertility via optimal sperm production and function.
Aitken RJ, Gordon E, Harkiss D, Twigg JP, Milne P, Jennings Z, Irvine DS.
Biol Reprod 1998;59(5):1037‐46.
This study investigated how sperm reacted to different levels of oxidative stress. Analyzing sperm’s movement, sperm-oocyte interaction and DNA integrity, the study showed that when sperm was exposed to low level of oxidative stress, DNA fragmentation decreased and the rates of sperm-oocyte fusion were enhanced. Inversely, at high levels of oxidative stress, sperm DNA damage increased. Sperm movement and oocyte fusion were lost altogether.
De Celis R, Pedron‐Nuevo N, Feria‐Velasco A.
Arch Androl 1996;37:201‐218.
This review lists environmental and occupational factors, such as heavy metals, organic compounds, alcohol, and cigarette smoking, that affect male fertility and reproduction.
Colin A, Barroso G, Gomez‐Lopez N, Duran E, Oehninger S.
Fertil Steril 2010;94:2609‐2614.
This cross sectional study examined the sperm of men ranging in age from 20 to 68 to determine how age influences the way sperm cells “die”. Advancing male age was found to significantly correlate with apoptosis biomarkers, and a clear trend for increased DHEA fragmentation in older male group was observed. The study confirmed that male age is associated with sperm death and resulting decrease in sperm concentration.
Schmid T, Eskenazi B, Baumgartner A, Marchetti F, Young S, Weldon R, Anderson D, Wyrobek A.
Hum Reprod 2007;22:180‐187.
Eighty non-smoking men with no known fertility issues were evaluated for DNA damage and the production of genetically defective sperm. Older men were found to demonstrate increased sperm DNA damage in conjunction with single-strand DNA breaks. The study also identified caffeine intake as risk factor for sperm DNA damage: Men who consume caffeine daily, regardless of age, had increased double strand DNA breaks in their sperm.
Singh N, Muller C, Berger R.
Fertil Steril 2003;80:1420‐1430.
This study evaluated semen samples from 66 men between 20 and 57 years to investigate the relationship between a man’s age and DNA damage in the sperm, as well as the apoptosis (“death”) of sperm cells. The result showed a direct correlation between age and DNA damage: percentage of sperm with high degree of DNA damage, among other parameters, was significantly higher among men 36-57 years than those 20-35 years. Sperm motility was significantly better in the younger men. This study was also the first to show an age-related decrease in sperm apoptosis, indicating an age-related deterioration of healthy sperm cell selection process.
Sloter E, Schmid T, Marchetti F, Eskenazi B, Nath J, Wyrobek A.
Hum Reprod 2006;21:2868‐2875.
To address the lack of quantitative information on the risk factors that affect sperm quality, this study performed a linear regression analyses on 14 aspects of semen quality in a group of 90 men ranging from 22 to 80 years of age. Participants were non-smokers and had no history of infertility. The findings revealed age-associated declines in sperm motility and three quantitative aspects of sperm motion (linearity, straight line velocity, and average path velocity).
Sartourius G, Nieschlag E.
Hum Reprod Update 2010;16:65‐79.
It is already known that maternal age has a negative effect on fertility, in addition to contributing to adverse outcomes in pregnancy and offspring. This study was conducted to review the influence paternal age has on fertility and on the risk of poor outcomes. Though findings of deteriorated sperm quality and decreased sexual activity were associated with an increase in paternal age, the study concluded that paternal age, on its own, does not justify invasive procedures.
Kidd S, Eskenazi B, Wyrobek A.
Fertil Steril 2001;75:237‐248.
This study takes a look at research published on sperm quality from January 1, 1980 through December 31, 1999. In the analysis of stronger-evidence studies, a decrease in semen volume, motility and the percentage of normal sperm were observed when comparing 50-year-old men to 30-year-old men. Based on the majority of the evidence from the studies evaluated, this review proposes a decline in sperm quality as men age.
Matorras R, Matorras F, Exposito A, Martinez L, Crisol L.
Gynecol Obstet Invest 2011;71:229‐235.
This study sorted 454,753 newborns for the year 2004 by paternal and maternal age groups to evaluate human fertility based on male age. The grouping showed that male fertility declined at age 35-39 and continues to follow a constant slope, revealing a 21-23% decrease in fertility starting at age 39. The authors attributed the age-related decline in male fertility to deterioration in sperm quality.
Amaral S, Amaral A, Ramalho‐Santos J.
Front Biosci 2013;S1:181‐197.
This study sought to provide an overview of how age affects the male reproductive system via mitochondrial function. The study proposes that oxidative stress on the mitochondria, changes in mitochondrial energy metabolism and mitochondrial-dependent testosterone production constitute a link between aging and male infertility.