title: Trans fatty acid intake is inversely related to total sperm count in young healthy men.
abstract: OBJECTIVE
  Is intake of fatty acids related to semen quality among young men?
  
  
  CONCLUSIONS
  The intake of trans fatty acids is inversely related to total sperm count in healthy young men.
  
  
  BACKGROUND
  Spain has seen an increase in the proportion of calories consumed as fat over the same period that a downward trend in semen quality has been observed. In addition, rodent models suggest that trans fat intake may severely affect testicular function.
  
  
  METHODS
  Cross-sectional study of 209 men recruited between October 2010 and November 2011.
  
  
  METHODS
  A group of 209 healthy young university students 18-23 years of age provided a semen sample and completed a previously validated food frequency questionnaire. The association between intake of fatty acids with semen quality parameters (sperm concentration, motility, morphology and total count) was assessed using multivariate linear regression.
  Trans fatty acid intake was inversely related to total sperm count after adjusting for potential confounders (P, trend = 0.03). The multivariate adjusted mean (95% confidence interval) total sperm count in increasing quartiles of trans fat intake was 144 (110-190), 113 (87-148), 100 (18-130) and 89 (69-117). There also was an inverse association between cholesterol intake and ejaculate volume (P, trend = 0.04). No other statistically significant relations were observed.
  
  
  CONCLUSIONS
  The cross-sectional design of the study limits causal inference, we cannot exclude the possibility of unmeasured confounding and there was insufficient statistical power to identify modest associations.
  
  
  CONCLUSIONS
  The results of this study, together with previous experimental work in rodents and biomarker studies among infertility patients, suggest that intake of trans fatty acids may be related to lower semen quality. Although the data provide further evidence that diet is a modifiable factor that could impact male fertility, it is not known whether the observed differences in sperm count translate into differences in fertility.
  
  
  BACKGROUND
  This work was supported by The Seneca Foundation, Regional Agency of Science and Technology, grant no 00694/PI/04, Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III (FIS), grant no PI10/00985, and grant P30 DK46200 from the National Institutes of Health. The authors have no competing interests to declare.
authors.affiliation: Department of Nutrition, Harvard School of Public Health, Boston, MA 02115, USA.
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Chavarro
authors.forename: Lidia
authors.initials: L
authors.lastname: Mínguez-Alarcón
authors.forename: Jaime
authors.initials: J
authors.lastname: Mendiola
authors.forename: Ana
authors.initials: A
authors.lastname: Cutillas-Tolín
authors.forename: José J
authors.initials: JJ
authors.lastname: López-Espín
authors.forename: Alberto M
authors.initials: AM
authors.lastname: Torres-Cantero
mesh_terms: D000293:Adolescent; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D003430:Cross-Sectional Studies; D004041:Dietary Fats / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D055101:Semen Analysis; D013076:Sperm Count; D044242:Trans Fatty Acids / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D002791:Cholesterol, Dietary; D004041:Dietary Fats; D044242:Trans Fatty Acids
keywords: fat intake; semen quality; trans fatty acids; young healthy men