Background: In the United States, anabolic sex steroids are administered to cattle for growth promotion. There is concern regarding the reproductive consequences of this practice in men who eat beef. We investigated whether meat consumption was associated with semen quality parameters and reproductive hormone levels in young men.
Methods: Semen samples were obtained from 189 men aged 18–22 years. Diet was assessed with a previously validated food frequency questionnaire. We used linear regression to analyze the cross-sectional associations of meat intake with semen quality parameters and reproductive hormones while adjusting for potential confounders.
Results: There was an inverse relation between processed red meat intake and total sperm count. The adjusted relative differences in total sperm counts for men in increasing quartiles of processed meat intake were 0 (ref), −3 (95% confidence interval = −67 to 37), −14 (−82 to 28), and −78 (−202 to −5) million (test for trend, P = 0.01). This association was strongest among men with abstinence time less than 2 days and was driven by a strong inverse relation between processed red meat intake and ejaculate volume (test for trend, P = 0.003).
Conclusions: In our population of young men, processed meat intake was associated with lower total sperm count. We cannot distinguish whether this association is because of residual confounding by abstinence time or represents a true biological effect.
From the aDepartment of Nutrition, bDepartment of Biostatistics, and cDepartment of Epidemiology, Harvard School of Public Health, Boston, MA; d Division of Preventive Medicine and Public Health, University of Murcia School of Medicine, Murcia, Spain; eUniversity Department of Growth and Reproduction, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark; fDepartment of Obstetrics and Gynecology, School of Medicine, University of Rochester, Rochester, NY; gDepartment of Preventive Medicine, Mount Sinai School of Medicine, New York, NY; and hChanning Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA.
The authors report no conflicts of interests.
This study was funded by European Union Seventh Framework Program (Environment), “Developmental Effects of Environment on Reproductive Health” (DEER) grant 212844, and grant P30 DK046200 and Ruth L. Kirschstein National Research Service Award T32 DK007703-16 from the National Institutes of Health.
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Correspondence: Myriam Afeiche, Department of Nutrition, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115. E-mail: firstname.lastname@example.org.