Mediterranean and western dietary patterns are related to markers of testicular function among healthy men.

Are there any associations of dietary patterns with semen quality, reproductive hormone levels, and testicular volume, as markers of testicular function? These results suggest that traditional Mediterranean diets may have a positive impact on male reproductive potential. The Mediterranean diet has been related to lower risk of multiple chronic diseases, but its effects on reproduction potential are unclear. Cross-sectional sample of 215 male university students recruited from October 2010 to November 2011 in Murcia Region (Spain). Two hundred and nine healthy men aged 18-23 years were finally included in this analysis. Diet was assessed using a validated food frequency questionnaire, and dietary patterns were identified by factor analysis. Linear regression was used to analyze the relation between diet patterns with semen quality parameters, reproductive hormone levels and testicular volume adjusting for potential confounders. We identified two dietary patterns: a Mediterranean (characterized by high intakes of vegetables, fruits and seafood) and a Western pattern (characterized by high intakes of processed meats, French fries and snacks). The Mediterranean pattern was positively associated with total sperm count (P, trend = 0.04). The Western pattern was positively related to the percentage of morphologically normal sperm (P, trend = 0.008). We found an inverse association between adherence to the Western pattern and sperm concentration among overweight or obese men (P, trend = 0.04). As with all cross-sectional studies, causal inference is limited. However, participants were blinded to the study outcomes thus reducing the potential influenced their report of diet. Although we adjusted for a large number of known and suspected confounders, we cannot exclude the possibility of residual confounding or chance findings. This study was carried out on healthy and young men, so it is difficult to predict whether and how the observed differences in semen quality translate into reproductive success for men in couples trying to conceive. These results suggest that traditional Mediterranean diets may have a positive impact on male reproductive potential.

Cutillas-Tolín A ，Mínguez-Alarcón L ，Mendiola J ，López-Espín JJ ，Jørgensen N ，Navarrete-Muñoz EM ，Torres-Cantero AM ，Chavarro JE ... -  《-》

Adherence to diet quality indices in relation to semen quality and reproductive hormones in young men.

Is adherence to an a priori defined diet quality indices [Alternate Healthy Index 2010 (AHEI-2010), relative Mediterranean diet score (rMED) or dietary approaches to stop hypertension (DASH)] associated with semen quality and reproductive hormone levels in young men? Greater adherence to the DASH diet is related to higher sperm counts. Studies assessing the relationship between dietary intake and male reproductive function have mainly been focused on specific nutrients, food groups or data-driven dietary patterns, but the evidence on a priori defined dietary indices is still scarce. Cross-sectional study of 209 male university students recruited from October 2010 to November 2011 in Murcia Region (Southern Spain). Healthy young men aged 18-23 years were included in this study. Diet was assessed using a validated food frequency questionnaire and three a priori-defined dietary indices (AHEI-2010, rMED and DASH) were calculated. Linear regression was used to analyze the relation between the three dietary indices and semen quality parameters and reproductive hormone levels accounting for potential confounders and covariates. We found statistically significant positive associations between the DASH index and sperm concentration (P, trend = 0.04), total sperm count (P, trend = 0.04) and total motile sperm count (P, trend = 0.02). No associations were observed for other semen parameters or male reproductive hormones. Even though we adjusted for several known and suspected confounders we cannot exclude the possibility of residual or unmeasured confounding or chance findings. Subjects were blinded to the study outcomes thus reducing the potential influence on their report of diet. Our sample size may be too small to rule out associations with other semen parameters or reproductive hormones. Causal inference is limited, as usual with all observational studies. The results suggest that greater adherence to the DASH may help improve sperm counts. This study was carried out on young men from the general population. However, results may differ among other populations (e.g. infertile men). Therefore, further research is needed to confirm these findings and extend these results to other populations. This work was supported by Fundación Séneca, grants No 08808/PI/08 and No 19443/PI/14; Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III (AES), grants No PI10/00985 and No PI13/01237; and grant P30DK046200 from the National Institutes of Health. Authors have no competing interests to declare.

Cutillas-Tolín A ，Adoamnei E ，Navarrete-Muñoz EM ，Vioque J ，Moñino-García M ，Jørgensen N ，Chavarro JE ，Mendiola J ，Torres-Cantero AM ... -  《-》

Association between adherence to the Mediterranean diet and semen quality parameters in male partners of couples attempting fertility.

Is adherence to the Mediterranean diet (MedDiet) associated with better semen quality in men of subfertile couples attempting fertility? Greater adherence to the MedDiet, as assessed through the validated Mediterranean diet score (MedDietScore), was significantly associated with higher sperm concentration, total sperm count and sperm motility. A-posteriori dietary pattern approaches have revealed that dietary patterns characterized by high intakes of fruits, vegetables, whole grains, fish and low intake of meat are associated with better semen quality. Yet, whether adherence to the MedDiet is associated with better semen profile remains largely unexplored. This was a cross-sectional study of 225 men from couples attending a fertility clinic in Athens, Greece, recruited between November 2013 and May 2016. The study was designed to evaluate the influence of habitual dietary intake and lifestyle on fertility outcomes. Men aged 26-55 years, 51.1% overweight or obese, 20.9% smokers, with complete dietary data were analyzed. Diet was assessed via a food-frequency questionnaire and adherence to the MedDiet was assessed through the MedDietScore (range: 0-55; higher scores indicating greater adherence to MedDiet). Semen quality was evaluated according to World Health Organization 2010 guidelines. Multiple logistic regression analysis was used to evaluate associations between tertiles of the MedDietScore and the likelihood of having abnormal semen parameters, after adjusting for potential confounders. Compared to men in the highest tertile of the MedDietScore (≥37, N = 66), a higher percentage of men in the lowest tertile of the score (≤30, N = 76) exhibited below the WHO reference values for sperm concentration (47.4% vs 16.7%, P < 0.001), total sperm count (55.3% vs 22.7%, P < 0.001), total motility (65.8% vs 31.8%, P < 0.001), progressive motility (84.2 vs 62.1%, P = 0.011) and sperm morphology (50.0 vs 28.8%, P = 0.023). In the multivariable adjusted models, men in the lowest tertile of the MedDietScore had ~2.6 times higher likelihood of having abnormal sperm concentration, total sperm count and motility, compared to men in the highest tertile of the score. The main limitation of the study stems from its cross-sectional nature, limiting our ability to determine causality. The results suggest that greater compliance to the MedDiet may help improve semen quality. Whether this translates into differences in male fertility remains to be elucidated. Our findings are consistent with previous studies showing that dietary patterns with some of the characteristics of the MedDiet, i.e. rich in fruit, vegetables, legumes and whole grains, are associated with better measures of semen quality. No funding was obtained. The authors have no competing interests to declare. n/a.

Karayiannis D ，Kontogianni MD ，Mendorou C ，Douka L ，Mastrominas M ，Yiannakouris N ... -  《-》

Trans fatty acid intake is inversely related to total sperm count in young healthy men.

Chavarro JE ，Mínguez-Alarcón L ，Mendiola J ，Cutillas-Tolín A ，López-Espín JJ ，Torres-Cantero AM ... -  《-》

Self-reported onset of puberty and subsequent semen quality and reproductive hormones in healthy young men.

Is there an association between pubertal onset and subsequent reproductive health in young men? Self-reported later onset of puberty was associated with reduced semen quality and altered serum levels of reproductive hormones among 1068 healthy, young Danish men. The long-term effects of variations in the onset of male puberty on subsequent reproduction remain largely unstudied. In a cross-sectional study, young healthy Danish men were approached when they attended a compulsory medical examination to determine their fitness for military service from 2008 to 2012. A total of 1068 healthy, young Danish men (mean age 19 years) participated. They were asked to assess whether onset of penile and testicular growth, development of pubic hair and voice break occurred earlier, at the same time as or later than their peers. Their semen quality (semen volume, sperm concentration, total sperm count and percentages of motile and morphologically normal spermatozoa) and serum concentrations of sex hormones (LH, FSH, total testosterone, SHBG, inhibin B) and testicular size were determined. The response rate was 29%. Of the 1068 men who then participated, 652 answered the questions about penile growth and pubic hair development and were therefore included in the analysis. Self-reported later onset of puberty was associated with a 25% reduction in sperm concentration (95% CI -41%; -4%), a 40% reduction in total sperm count (-55%; -21%), a 1.6% age point reduction in morphological normal spermatozoa (-2.9; -0.3) and a 1.6 ml reduction in testicular size (-2.4 and -0.8 ml), after adjustment for confounders. Self-reported later onset of puberty was also associated with a 9% (3%; 15%) reduction in free testosterone and a 16% (2%; 31%) increase in FSH, after adjustment for confounders. Our study was cross-sectional and reverse causality cannot be ruled out. In addition, we cannot rule out the possibility that the men with late puberty onset had not yet fully matured although most were in Tanner stage 5. Approximately 15% of young Danish men have self-reported later onset of puberty than their peers. We found poorer testicular function in young men with a history of later pubertal development, suggesting that timing of pubertal onset may be a fundamental marker of male reproductive health. However, we cannot exclude the possibility that these men had not fully matured at the time of examination and therefore their semen quality may yet improve, which makes follow-up important. This work was supported by the Danish Council for Strategic Research, Program Commission on Health, Food and Welfare (project number 2101-08-0058), Rigshospitalet (grants 961506336 and R42-A1326), European Union, DEER (grant agreement no 212844), the Danish Ministry of Health and the Danish Environmental Protection Agency and Kirsten and Freddy Johansens Foundation (grant 95-103-72087). There are no competing interests.

Jensen TK ，Finne KF ，Skakkebæk NE ，Andersson AM ，Olesen IA ，Joensen UN ，Bang AK ，Nordkap L ，Priskorn L ，Krause M ，Jørgensen N ，Juul A ... -  《-》