Background/objectives: The study aim was to evaluate the association between UPF consumption and semen quality in a sample of healthy young men in Italy.
Methods: A cross-sectional analysis was carried out using data from 126 participants (mean age ± SD 20.0 ± 1.2 years) enrolled in the FASt randomized controlled trial. Food intake was assessed through the European Prospective Investigation into Cancer and Nutrition (EPIC) FFQ. Food items were categorized according to the Nova classification based on their purpose and extent of processing as follows: (1) unprocessed/minimally processed foods; (2) processed culinary ingredients; (3) processed foods; and (4) UPFs. The weight ratio (%) between each Nova group (g/d) and total food (g/d) was then calculated. For semen analyses, sperm volume, concentration, motility and morphology were measured. The associations between UPF consumption (quarters of) and semen quality parameters were estimated using multivariable-adjusted linear regression models.
Results: Participants consuming high UPFs (Q4), compared to those in the bottom category of intake (Q1), had a lower sperm concentration (β = -54.16 × 106 cell/mL; 95%CI: -92.91 to -15.40; p for trend = 0.0020 across fourths) and progressive motility (β = -14.17%; 95%CI: -28.25 to -0.09; p for trend = 0.036). The percentage of normal morphology cells had a tendency to decrease amongst subjects consuming more UPFs compared to those with the lowest intake.
Conclusions: A large dietary intake of UPFs was inversely associated with sperm concentration and progressive motility in reproductive-age men. These findings suggest that dietary recommendations for improving male fertility and sperm health should also recommend limiting UPFs.
Keywords: reproductive factors; semen quality; ultra-processed food.