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According to US clinic, daily intake of antioxidant for three months does not improve sperm concentration, motility or morphology, nor to the rate of DNA fragmentation. The study was performed in eight American fertility centers with the support of the National Institutes of Health. All the participants had been diagnosed with male factor infertility, reflected in sub-normal levels of sperm concentration, motility, or morphology, or higher than normal rates of DNA fragmentation.
The sperm parameters were measured at the beginning of the trial and at three months. In between, the men allocated to the antioxidant intervention were given a daily supplement containing vitamins C, D3 and E, folic acid, zinc, selenium and L-carnitine; the control group received a placebo. At three months, results showed oa slight difference in sperm concentration between the two groups, and no significant differences in morphology, motility, or DNA fragmentation measurements.
Sub-group analysis (according to different types of sperm abnormality) found no significant differences in sperm concentration (in oligospermic men), motility (in asthenospermic men), and morphology (in teratospermic men). There was also no change after three months in men with high rates of DNA fragmentation.
Natural antioxidants, including vitamins C and E, are found in semen ostensibly as protection against the activity of free radicals and oxidative stress. Several studies have shown that antioxidant levels are lower in the semen of infertile than in fertile men, this explains the rationale for antioxidant supplementation. DNA fragmentation is a measure of structural defects of sperm cells. Oxidative stress in the form of reactive oxygen species has been implicated in their interaction with DNA to cause strand breaks and fragmentation. haleplushearty.org