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Treating Male Infertility

The emerging emphasis on oxidative stress, and science-based supplements shown to support conception.

Infertility is a widely recognized and rapidly increasing problem, affecting about 15 percent of couples worldwide. In the United States, fertility has largely followed a downward trajectory, falling to a record low in 2020 when 43 states recorded their lowest fertility rates in three decades. And while interventions have historically focused on women, male infertility is a common issue, involved in 30 to 50 percent of cases. The etiology of male infertility is not completely understood: environmental, behavioral and genetic factors are implicated, but in one in three patients, a specific cause is still not identified. Now, a growing body of evidence highlights the role of oxidative stress in disorders of sperm production, maturation or function and seminal fluid quality. What the research shows, and promising new approaches for treating male infertility.1, 2


Male infertility: influences and interventions.

The causes of male infertility are broad and varied, each with different influences on diverse aspects of spermatogenesis. Genetic factors, hormonal imbalances or disorders, testicular damage, infection or injury, and medical conditions like varicocele are all known to affect sperm parameters. Lifestyle, behavioral and environmental factors are significant: excessive alcohol consumption, smoking, certain medications, including testosterone replacement therapy, and exposure to chemicals, pesticides or heavy metals diminish sperm quality and male fertility.3, 4, 5, 6

Obesity, chronic stress and insufficient sleep are linked with decreased sperm production and motility. A sedentary lifestyle negatively affects sperm parameters, but excessive exercise, especially cycling and other intense activities that raise scrotal temperature, have been shown to impair sperm production and function. Diets rich in fruits, vegetables and lean protein promote sperm quality, while increased intake of sugar and trans fats are linked with lower sperm counts, reduced motility and abnormal morphology.7, 8, 9, 10, 11, 12

Along with dietary interventions aimed at correcting deficiencies, specific nutrients can support sperm quality and enhance fertility, primarily by protecting against reactive oxygen species (ROS) that impact spermatogenesis and decrease male fertility. Emerging research emphasizes the strong association between oxidative stress and poor semen quality. Studies suggest 30 to 80 percent of infertile men have elevated seminal levels of ROS, and antioxidant therapy is considered a cornerstone of male infertility treatment.13, 14, 15

In addition to addressing diet, lifestyle and environmental influences, a personalized protocol should include evidence-based antioxidants proven to protect against ROS, promote healthy sperm parameters and foster fertility.


Science-backed supplements for supporting male fertility.

Zinc’s antioxidant properties shield sperm from ROS production and DNA damage, and adequate intakes improve sperm morphology, viability and motility. Deficiencies are correlated with a decrease in male fertility: zinc levels in the seminal plasma of infertile males have been shown to be lower compared to controls, and one meta-analysis found zinc concentrations in seminal plasma were positively associated with male fertility. In other studies, supplementation significantly increased sperm volume, sperm motility and percentage of normal sperm morphology.16, 17, 18

Folate is important for DNA synthesis and integrity, and low levels are related to a higher risk of sperm chromosomal abnormalities. Folic acid is known to counteract ROS and decrease inflammation, and studies link deficiencies with impaired spermatogenesis and reduced sperm concentration. While findings are mixed, evidence suggests folic acid supplementation can enhance male fertility, and in one review, folic acid alone showed the potential to improve sperm motility and IVF–ICSI outcomes.19, 20, 21

Vitamin D has both antioxidant and anti-inflammatory properties, and research points to its protective effects on DNA and cell membranes. Vitamin D levels are correlated with sperm parameters, especially motility, and several trials demonstrate a link between deficiencies and reduced sperm motility, sperm count and semen quality. Other interventional studies found vitamin D supplementation significantly increased sperm motility and rate of pregnancy.22, 23, 24

Omega-3 fats, primarily DHA, are essential for sperm cell flexibility and movement, vital to sperm performance. Imbalanced ratios of omega-6 to omega-3 can impair sperm quality and motility, and research suggests men with fertility issues had higher omega-6 to omega-3 blood ratios compared to fertile men. DHA has known antioxidant and anti-inflammatory properties, and in one meta-analysis, omega-3 supplementation boosted DHA concentrations and positively influenced sperm motility in men with fertility problems.25, 26, 27

L-carnitine, found in high concentrations in the male reproductive tract, plays a crucial role in energy metabolism and spermatozoa maturation. The antioxidant properties of L-carnitine protect against ROS, and studies show L-carnitine maintains sperm function, enhancing motility and epididymal function. L-carnitines supplementation is linked with significant improvements in sperm parameters and positive impacts on male fertility. Other research suggests L-carnitine supplementation reduces ROS levels, promotes sperm quality and increases fertility rates, even at a relatively low dose of 2 grams per day.28, 29, 30

Coenzyme Q10 (CoQ10) is involved in mitochondrial energy production, essential for maintaining the efficient energy system of spermatozoa and protecting their membranes from lipid peroxidation. Diminished levels are associated with several conditions determining infertility, such as varicocele and low sperm concentrations, and a number of studies link higher blood and seminal plasma CoQ10 with increased sperm count, motility and morphology. Supplementation has been shown to improve sperm parameters, including significant increases in total sperm counts and sperm cell motility, and some research suggests CoQ10 boosts fertility and total pregnancy rates.32, 33


About CoQ10: why ubiquinol is better.

While CoQ10 is effective, ubiquinol—a reduced and more absorbable form of CoQ10—is a superior approach to enhancing sperm quality and promoting male fertility. When CoQ10 is taken as a supplement, it must be converted to ubiquinol. The efficiency of conversion is affected by various factors, including genetic influences, nutrient deficiencies and certain medications, and ability to convert CoQ10 to ubiquinol markedly declines with age. Taking ubiquinol directly as a supplement bypasses the conversion process, providing the body with the active form of CoQ10. It’s also highly bioavailable, with studies showing ubiquinol is two to four times better absorbed than conventional CoQ10.34, 35, 36

In terms of its impact on male fertility, research points to a strong correlation between sperm count, motility and ubiquinol concentration in seminal fluid. Ubiquinol has been shown to improve multiple sperm parameters, with significant increases in sperm count, density, motility and morphology seen after daily ubiquinol supplementation of 150 to 200 mg.37, 38, 39

Other research demonstrates its efficacy in supporting male fertility:

  • An open-label, six-month study of men with low sperm count found that supplementing with 150 mg of ubiquinol once daily lead to a 53 percent increase in sperm count, a 26 percent increase in total sperm motility and a 41 percent increase in absolute numbers of rapidly swimming sperm, compared to placebo.41
  • In a retrospective six-month study of men with low sperm motility and abnormal sperm morphology but normal sperm count, fast-moving sperm increased from 5.7 percent to 11.5 percent, and sperm morphology improved from 2.6 percent to 3.1 percent, with 100 mg of ubiquinol twice a day, compared to placebo.42



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