Associations between dietary inflammatory index and male reproductive parameters

The aim of this work was to assess the associations between the dietary inflammatory index (DII) and male reproductive parameters. Cross-sectional study of 209 healthy male university students (18-23 years old) recruited from October 2010 to November 2011 in Murcia Region (Southern Spain). Semen analyses (sperm concentration, motility and morphology) were carried out according to World Health Organization guidelines. Serum concentrations of follicle-stimulating and luteinizing hormones, estradiol, inhibin b and testosterone were also determined. Diet intake was assessed using a validated food frequency questionnaire. The DII assessed the inflammatory potential of one's diet. Negative or positive values of DII reflected anti-inflammatory or pro-inflammatory dietary status, respectively. Linear regression was used to analyze the relation between the DII score and semen quality parameters and reproductive hormone levels adjusting for potential important covariates. We found statistically significant positive associations between the DII and progressive sperm motility (PR) (P, trend=0.03] and total sperm motility (PR+NP) (P, trend=0.04]. No significant associations were observed for other semen parameters or male reproductive hormones. Our results suggest that a pro-inflammatory dietary status may be associated with increased sperm motility in young men, but will not impact sperm count, morphology or reproductive hormones. However, further research is needed to confirm these findings and extend these results to other male populations.