Healthy and unhealthy dietary patterns and sperm quality from the Led-Fertyl study.

Background: Dietary patterns may affect sperm quality, but the scientific evidence is limited.

Objective: To evaluate the association between adherence to different a-priori dietary patterns and sperm quality parameters in healthy reproductive-age men.

Materials and methods: A cross-sectional analysis was conducted using data from 200 young men enrolled in the Led-Fertyl study. Tertiles of six a-priori dietary patterns were estimated: four healthy dietary patterns [Mediterranean Diet Adherence Screener (MEDAS), Dietary Approaches to Stop Hypertension (DASH), Healthful Plant-Based Diet Index (hPDI) and EAT-Lancet Score], and two unhealthy dietary patterns [Western Diet and Unhealthful Plant-Based Diet Index (uPDI)]. Sperm quality parameters (count, concentration, vitality, total and progressive motility, and normal morphology) were considered the main outcomes.

Results: Compared with the lowest tertile, participants in the highest MEDAS tertile had higher total sperm count (β = 3.2;95%CI: 1.0, 5.5) and concentration (β = 1.8;95%CI: 0.6, 3.0), and total (β = 8.2;95%CI: 1.3, 15.1) and progressive motility (β = 7.1;95%CI: 0.2, 14.0). Similarly, participants in the highest hPDI tertile had higher total sperm count (β = 3.4;95%CI: 1.4, 5.5) and concentration (β = 1.2;95%CI: 0.0, 2.3) compared with those in the lowest tertile. When these dietary patterns were modelled as continuous variables (for each 1-point increment in the specific score), an inverse association was found between the uPDI and Western and total sperm count [(β = -2.7;95%CI: -4.8, -0.7) and (β = -3.8;95%CI: -5.8, -1.7), respectively] and sperm concentration [(β = -1.2;95%CI: -2.4, -0.1) and (β = -1.7;95%CI: -2.8, -0.5), respectively]. Compared with participants in the lowest tertile, those in the highest uPDI tertile presented higher odds of abnormal sperm concentration (OR: 4.6;95%CI: 1.0, 19.9) and one or more seminogram abnormalities (OR: 2.3;95%CI: 1.1, 5.0).

Conclusions: Our findings suggest that higher adherence to healthy dietary patterns (Mediterranean and healthful plant-based diet) was positively associated with better sperm quality parameters, in contrast, greater adherence to unhealthy dietary patterns was inversely associated.