Male semen is a mixture of secretions of different glands, composed of several different components;
acid phosphatase
citric acid
inositol
copper
calcium
zinc
magnesium
fructose
seminogelin
vitamins C and E
prostaglandins
carnitine
glycerophosphato-choline
neutral alpha-glucosidase
Additionally, sperm also consists of protein, carotenoids, electrolytes-sodium, potassium, glucose, selenium, urea, lactic acid, and cholesterol.
As many of the components are sourced from food, a well balanced diet is essential for proper spermatogenesis and maturation of spermatozoa and their functioning. Thus, when there is an insufficient supply of the components in the diet spermatogenesis, sperm quality, and male fertility may be affected.
Depending on the diet, the pH of sperm ranges from 7.2 to 8.2.
According to some data, the quality of human semen has deteriorated by 50%–60% over the last 40 years. This has been attributed to a high-fat diet and obesity. As a result, the structure and quality of sperm is affected.
Nutritional Model Increasing the Risk of Male Infertility
The Western Diet has become the nutritional model of both developing and developed countries. The diet is characterized by a high intake of animal proteins, saturated and trans fatty acids, and simple carbohydrates, as well as, a low supply of dietary fibre and essential unsaturated fatty acids (EFA). Additionally, it is a hyper-caloric diet that is pro-inflammatory, with low nutritional density, which has been linked associated with poor quality of semen and reduced fertility.
Several studies have demonstrated, the consumption of meat, especially processed meat, has a detrimental effect on fertility. The trans fatty acids present in meat have been associated with poor sperm quality, lower sperm concentration in ejaculate, decrease in sperm motility, reduced testosterone production and testicular mass.
In addition, it is worth mentioning that it has been observed that when omega-6 fatty acids supply is too high in relation to omega-3 fatty acids, fertility is negatively affected by inducing inflammation and oxidative stress.
Oxidative stress constitutes the key mechanism and one of the main factors that associates improper diet and obesity with decreased sperm quality and a higher risk of infertility. Consequently, it has been associated with deterioration of testicular endocrine function, resulting in lower concentration levels of free testosterone, total testosterone, and lower testicular volume. Moreover, a moderate intake of soy products has also been associated with an increased risk of infertility, deterioration of semen quality, and a decrease in blood testosterone levels.
Environmental factors and poor lifestyle choices like smoking cigarettes and cannabis, excessive alcohol consumption, anabolic steroid use, emotional stress, excessive exposure to high temperatures, increasing age, the use of tight clothing, environmental pollution, a sedentary lifestyle, exposure to pesticides and toxins, radiation, as well as cytotoxic drugs, cadmium, and lead have also been associated with male infertility.
Certain factors such as environmental pollution, radiation or even age, cannot be avoided. however, Fertility can be improved by modifying bad lifestyle habits.
Chronic alcohol intake has been linked with decreases in androgens and sperm parameters, thus leading to deterioration of both semen volume and sperm morphology. It has been observed that cigarette smoking increases seminal oxidative stress and decreased sperm quality.
The use of drugs like opioids has been observed to diminish spermatogenesis directly in the testis. Evidence suggests that discontinuation of opioid analgesics may be associated with rapid return of androgen, perhaps as early as within 1 month. Sulfasalazine prescribed for inflammatory bowel conditions has also been associated with oligoasthenospermia. However If sulfasalazine is substituted with enteric-coated mesalazine, adverse effects on sperm are usually reversible.
Also, obesity has been associated with poor semen and reduced fertility in men as it has leads to insulin resistance, decrease in leptin, systemic inflammation, sleep apnea, and testicular thermo-regulation . Weight loss in obese men seems to be the first and most basic step in the treatment of male infertility.
Nutritional Recommendation to Increase Male Fertility
The Mediterranean Diet is considered to be a dietary model within the principles of a pro-fertility diet. It is characterized by the consumption of large quantities of fruit and vegetables, wholesome products, lean protein, low-fat dairy products, olive oil, nuts, fish and seafood. Many health benefits of the Mediterranean diet have been demonstrated, mainly due to its antioxidant, anti-inflammatory, and lipid-reducing effects.
This healthy dietary model correlates with better sperm quality and a smaller risk of abnormalities in parameters such as sperm count, sperm concentration and motility, and lower sperm DNA fragmentation.
Apart from mineral components such as zinc and selenium, the role of omega-3 fatty acids and antioxidant vitamins should be emphasized, since their action will be primarily based on the minimization of oxidative stress and the inflammation process. Furthermore, it seems promising to include carnitine and coenzyme Q10 supplements in the therapeutic intervention.
Zinc constitutes the basic element in the context of male fertility. Both seminal plasma and the prostate gland are characterized by its high content. The appropriate level of zinc in semen is essential for the production of spermatozoa, preservation of their correct morphology, sperm count and function, and thus, for the proper course of fertilization.
Selenium, vitamin C and tocopherol also present antioxidant properties by means of free radical neutralization. Thus, it is important for the diet to be rich in vegetables and fruits which are th main sources of these elements.
Green-leaved vegetables are a source of folic acid, which is important in the course of spermatogenesis, particularly when combined with zinc.
According to researchers, coenzyme Q10 may also be relevant in terms of semen quality., while the consumption of L-carnitine It has been shown to have a positive impact on sperm maturation and motility and spermatogenesis.
Lycopene, is powerful antioxidant belonging to the carotenoid family that can be found in Tomatoes. There has been shown that the consumption of lycopene may benefit sperm morphology.
The presence of N-acetyl-cysteine (NAC) in the diet of infertile men has been associated with an increased number and motility of spermatozoa, as well as an increased number of normal structure spermatozoa following 3 months of supplementation. Moreover, a decrease in sperm DNA fragmentation and an increase in protamine levels, as well as a decrease in FSH and LH and an increase in testosterone levels in blood.
Omega-3 Fatty Acids are also known to have anti-inflammatory and antioxidant properties. Supplementation with Omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) significantly increases sperm motility and DHA concentration in semen.
The consumption of fish and seafood has also been associated with better sperm quality in observational studies. In addition, the consumption of 75 g of walnuts per day over a 12 week period was associated with a longer lifespan, motility, and sperm morphology.
Adequate supply of magnesium and calcium is a key element in the course of spermatogenesis and sperm motility. Calcium affects the motility, hyper-activation, and capitulation of sperm and ultimately, the acrosome reaction, leading to sperm penetration
Furthermore, Copper is also necessary for the proper functioning of sperm and Manganese affects the motility of sperm and the fertilization process. Nevertheless, both manganese and copper in excessive amounts show an adverse effect on sperm.
The most frequently used antioxidants, both in monotherapy and combined supplementation, include vitamin E and C, L- carnitine, coenzyme Q10, zinc, selenium, folic acid, and N-acetylcysteine
References:
Clinical Reproductive Medicine and Surgery. A Practical Guide.Third Edition. Tommaso Falcone William W. Hurd.Chapter 11. Male Infertility. Springer.
Campbell-Walsh Urology. Eleventh Edition. Chapter 24 Male Infertility. Elsevier.
European Association of Urology. Guideline of Sexual and Reproductive Health 2021. Chapter 10: Male Infertility.
American Urological Association. Guideline Infertility-Optimal Evaluation of the Infertile Male 2011.
Journal of Clinical Medicine (MDPI). Diet and Nutritional Factors in Male (In)fertility—Underestimated Factors. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7291266/
J Clin Med. 2020 May; 9(5): 1400. Published online 2020 May 9. doi: 10.3390/jcm9051400
Male infertility: management. Urology Care Foundation website. http://www.urologyhealth.org/urology/index.cfm?article=29.
Gaskins AJ, Colaci DS, Mendiola J, Swan SH, Chavarro JE. Dietary patterns and semen quality in young men. Hum Reprod. 2012; 27(10):2899-2907.
American Society for Reproductive Medicine (ASRM). Diagnosis and Treatment of Infertility in Men. https://www.asrm.org
(In)Fertility Secrets, Struggles, & Successes Wise Women Book Collective. Chapter 1: Holistic Approach to Fertility Dr. Aumatma, ND