The time-dependent adverse effects of a high-fat diet on sperm parameters

BACKGROUND: Studies indicate a relationship between a high-fat diet (HFD) and sperm quality. However, the time-dependent adverse effects of a HFD on sperm parameters and the underlying mechanisms remain unclear. OBJECTIVES: The present study was designed to determine the effects of a HFD on sperm quality at various time points in order to assess whether a HFD causes cumulative damage to sperm. MATERIAL AND METHODS: Male C57BL/6 mice were fed a normal diet (the ND group) or a HFD (the HFD group) for 16, 30 or 42 weeks (n = 6 for each group). Body weight, lipid profile, sperm parameters, testicular morphology, and testicular oxidative stress levels were evaluated alongside the proliferation, DNA damage and rate of germ cell apoptosis. RESULTS: Sperm quality was reduced in HFD-fed animals in a time-dependent manner, which was demonstrated by a decline in sperm density, motility and progressive motility. Further analysis showed a progressive deterioration of the testicular histoarchitecture of HFD-fed mice, which was accompanied by a decrease in DEAD-box helicase 4 (DDX4) expression and superoxide dismutase (SOD) levels, increased malondialdehyde (MDA) levels and gamma-H2A histone family member X (γ-H2AX) expression, and increased apoptosis of germ cells. CONCLUSIONS: These findings demonstrate that a HFD exerted adverse effects on sperm quality, and the deteriorating effect was progressive with long-term feeding. The inhibited proliferation and apoptosis of germ cells, and the increased oxidative stress levels and DNA damage may be the underlying mechanisms.