Dietary patterns and semen quality in young men.

STUDY QUESTION: Are different dietary patterns associated with semen parameters in young men?

STUDY ANSWER: The consumption of a Prudent dietary pattern was significantly associated with higher progressive sperm motility and unrelated to sperm concentration and morphology. The consumption of a Western dietary pattern was unrelated to conventional semen quality parameters.

WHAT IS KNOWN ALREADY: Over the past decades there has been evidence of a concomitant decline in sperm and diet quality. Yet whether diet composition influences semen quality remains largely unexplored.

STUDY DESIGN, SIZE, DURATION: The Rochester Young Men's Study (n= 188) was a cross-sectional study conducted between 2009 and 2010 at the University of Rochester.

PARTICIPANTS, SETTING, METHODS: Men aged 18-22 years were included in this analysis. Diet was assessed via food frequency questionnaire and dietary patterns were identified by factor analysis. Linear regression was used to analyze the relation between diet patterns and conventional semen quality parameters (sperm concentration, progressive motility and morphology) adjusting for abstinence time, multivitamin use, race, smoking status, BMI, recruitment period, moderate-to-intense exercise and total calorie intake.

RESULTS: Two dietary patterns were identified by factor analysis. The 'Western' pattern was characterized by high intake of red and processed meat, refined grains, pizza, snacks, high-energy drinks and sweets. The 'Prudent' pattern was characterized by high intake of fish, chicken, fruit, vegetables, legumes and whole grains. The Prudent pattern was positively associated with percent progressively motile sperm in multivariate models (P-trend = 0.04). Men in the highest quartile of the Prudent diet had 11.3% (95% CI 1.3, 21.3) higher % progressively motile sperm compared with men in the lowest quartile. The Prudent pattern was unrelated to sperm concentration and morphology. The Western pattern was not associated with any semen parameter.

LIMITATIONS: This was a cross-sectional and observational study, which limited our ability to determine causality of diet on semen quality parameters.

WIDER IMPLICATIONS OF THE FINDINGS: Our findings support the suggestion that a diet rich in fruits, vegetables, chicken, fish and whole grains may be an inexpensive and safe way to improve at least one measure of semen quality.

STUDY FUNDING/COMPETING INTERESTS: The authors are supported by NIH grant T32DK007703-16 and P30DK46200 and European Union DEER Grant 212844. The authors have no competing interests to declare.