Male infertility may result from multiple factors such as hormonal imbalances (hypothyroism, increased prolactin, low production of FSH and LH hormones), anatomical problems (varicocele), inflammation, infections, as well as due to psychological roots (increased levels of stress, low self esteem). The most common cause is low sperm numbers (oligozoospermia) and potential alterations in the form/shape or structure and the mobility of sperm.
Important factors negatively affecting sperm quality are:
- Obesity: Studies have demonstrated that increased BMI (32-43 kg/m2) is positively related to infertility.
- Malnutrition may lead to anemia and vitamin (folic acid, vitamin C) and micronutrient (selenium, zinc) deficiency.
- Increased processed meat consumption is associated with decreased production of morphologically normal sperm.
- High intake of soy isoflavones (glycitein) and increased consumption of soy and derived products has a negative impact in fertility, especially when combined with male obesity.
- Excessive alcohol consumption.
- Extremely intense exercise can reduce testosterone levels.
- Exposure to radiation and toxic chemicals (lead, benzene, mercury).
- Tobacco and marijuana use.