Dietary antioxidants and micronutrient status in varicocele-associated male infertility: oxidative stress-mediated effects on semen quality

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Background Varicocele causes male infertility through its association with oxidative stress that damages sperm. Dietary antioxidants together with micronutrients help to lower oxidative stress while enhancing sperm production, but their impact on varicocele-related infertility remains to be proven. Methods The researchers conducted a retrospective cohort study of 900 men with varying degrees of varicocele, including 300 with Grade I, 400 with Grade II, and 200 with Grade III. The study collected data on participants’ demographics, body measurements, daily habits, food consumption, micronutrient levels, oxidative stress indicators, antioxidant enzyme activity, reproductive hormone levels, semen characteristics, and reproductive success. The study used multiple linear and logistic regression analyses to identify factors affecting sperm concentration and motility, DNA fragmentation, and spontaneous conception. The researchers used standardized beta coefficients to quantify the contribution of each main predictor variable to the results. Results The negative effects on sperm concentration and motility are attributable to varicocele severity, age, BMI, smoking, reactive oxygen species (ROS), and malondialdehyde (MDA), which generate DNA fragmentation, thereby establishing statistical significance at p < 0.05. The dietary antioxidants vitamin C, vitamin E, zinc, and selenium had positive effects on sperm concentration ( β = 0.09–0.18) and motility ( β = 0.10–0.16), while they had negative effects on DNA fragmentation ( β = −0.07 to −0.15). The regression models explained 40–42% of the variability in sperm parameters. The logistic regression analysis found that antioxidant consumption increased the probability of natural conception (OR 1.05–1.13, p < 0.01), whereas age, BMI, varicocele degree, smoking, and ROS and MDA reduced the probability of conception (OR 0.64–0.97, p < 0.05). Clinical outcomes tracked 30% of participants who achieved natural conception, while 25% underwent assisted reproductive technology (ART) cycles, and the group attained a live birth rate of 28%. The group with Grade I varicocele and higher antioxidant intake showed improved outcomes. Conclusion Men with varicocele demonstrated impaired sperm quality and reduced fertility potential, which appeared to be associated with increased oxidative stress and alterations in antioxidant status. The findings also suggest that lifestyle and dietary antioxidant intake may play a contributory role in modulating these effects.