by: Rebecca Lee, ND
Marsden Centre of Naturopathic Excellence
2338 Major McKenzie Dr W
Maple, Ontario L6A3Y7
Infertility: His Side
The word “infertility” tends to conjure up images of women. Generally speaking, the woman is the one who is given responsibility in all aspects of child-bearing, and most times the main aspects of child-rearing in a large portion of the world. However, as we know, she is not the only factor in the baby-making equation. The man’s ability to participate in this seemingly simple arithmetic formula is just as important.
How widespread is infertility? Infertility is defined by most as the inability to become pregnant after one year of unprotected sex. It is estimated that around 10–15% of couples are affected by infertility. In 2010, an astounding 48.5 million couples worldwide desired, but were unable to have a child after five years of trying to conceive!
How does “the man” factor into such high infertility numbers? Interestingly, it appears that over time, average sperm counts have decreased globally. For instance, in the 1940s, the lower reference value for a “normal” sperm count was 60 × 106/ml, whereas today it is a mere 20 × 106/ml.
It is estimated that 40–90% of male infertility cases are due to poor sperm production of which the cause is unidentifiable. However, there is a range of factors that play an important role in sperm health that are modifiable, and once improved have the potential to increase fertility. Lifestyle factors that affect male fertility are similar to that of female fertility and include age, diet, weight, exercise, stress, environmental and occupational exposures, smoking, alcohol, recreational drug use, and caffeine consumption. In addition, there are factors like excessive heat or radiation, genitourinary infections, thyroid conditions, and other endocrine conditions that negatively affect male fertility.
Factors that Affect Male Fertility
It is well-recognized that fertility peaks and then decreases over time in women, but how does this compare in men? A look at their reproductive timeline shows that men are also vulnerable to the march of time. As early as 35 years of age, the characteristics of sperm cells begin a steady decline. Semen volume and motility (or movement) both decrease, and morphology (the shape and look of the sperm) may become progressively more abnormal. In fact, after the age of 40, men can have significantly more DNA damage in their sperm, as well as decrease in both sperm motility (40%) and viability, a measure of how long sperm live (below 50%).
Diet plays a large role in sperm health, as it does in the health of the whole body. A diet rich in carbohydrates, fiber, folate, and lycopene, as well as fruit and vegetables has been linked to enriched semen quality. Lower amounts of both proteins and fats were seen to be more beneficial for fertility as well.
Obesity is increasing in our society, and it poorly affects the quality of the male sperm. What is considered obese? Body mass index (BMI) is a ratio of height to weight. The BMI system defines underweight as a BMI of 18.5, normal at 18.5–24.9, overweight at above 25, and obese at over 30. BMI may be an important factor, as an increase in BMI by as little as three units can be associated with infertility. In addition, obese men are three times more likely to have reduced semen quality than men with a normal weight. This reduced quality of sperm is seen as a decrease in sperm concentration and in motility, as well as more DNA damage in sperm.
While obesity is not good for fertility, neither is too much exercise. Bicycling for more than five hours per week has been shown to have a negative impact on sperm counts and concentration. Physically active men who exercise at least three times a week for one hour typically scored higher in almost all sperm parameters (shape, motility, etc.) in comparison to men who participated in more frequent and rigorous exercise. This may be due to the increase in temperature of the scrotum that is reached at more strenuous exercise. Scrotal temperature is highly regulated by the body and sperm production is greatly reduced at temperatures above 96 °F.
Another lifestyle factor that is both modifiable yet difficult for many to achieve is smoking cessation. Smoking affects both female and male fertility in a negative way. Cigarette smoking has been associated with decreased sperm count, alterations in motility, and an overall increase in the number of abnormal sperm.
It must be taken into account that certain medications can increase infertility in men as well. Prescription drugs, including glucocorticoids, sulfasalazine, and nitrofurantoin all may have detrimental effects on sperm production and motility.
External hormone exposure is also a big aspect to fertility. Increased exposure to estrogens is thought to be responsible for testicular damage when in the womb and before birth. It can also contribute to decreased testicular function and spermatogenesis (the ability to make sperm) after birth, as it might also directly affect testosterone production. Diethylstilbestrol (DES), a synthetic estrogen, is well-documented for such effects. DES was prescribed from 1945 to 1971 to millions of women during pregnancy. Later, it was found that sons from these women had a higher incidence of developmental abnormalities of the reproductive tract, and diminished sperm volume and sperm count. Importantly, synthetic hormones are often found in our food sources. In fact, synthetic estrogens are widely used in the livestock, poultry, and dairy industries.
Exposure to pesticides affects many body organs, and the reproductive system is no different. Chemicals like dioxins, dichlorodiphenyltrichloroethane (DDT), and polychlorinated biphenyls (PCBs) — all commonly used pesticides — interfere with spermatogenesis. Pesticides were seen to potentially reduce the semen quality in exposed workers. The majority of pesticides, including organophosphoruses, affect the male reproductive system by mechanisms such as reduction of sperm density, motility, and viability, and through inducing sperm DNA damage and increasing abnormal sperm morphology. Moreover, DDT and its metabolites have estrogenic effects on males.
Heavy metals may also have a negative effect on male fertility. For example, in Hong Kong, infertile males were found to have higher hair mercury levels (about 40% higher) than fertile males of similar age. Occupational exposure to lead has also been shown to cause a significant decrease in male fertility.
Possible Supplementation Strategies for Male Infertility
Both female and male fertility can benefit from supplementation of different vitamins, minerals, or nutraceuticals. While dietary strategies provide some level of nutrient delivery, many nutrients need to be supplemented at higher therapeutic dosages in order to achieve effective levels. Having adequate amounts of certain compounds is extremely important in multiple body systems as well as the reproductive system. For instance, low amounts of zinc, selenium, and antioxidants were seen in the semen of male partners of infertile couples. As with all supplements, it is important to get advice from a licensed health-care practitioner, as some of these can have negative interactions with other medications or conditions.
Coenzyme Q10 (CoQ10) is a supplement that is often used for heart conditions, including hypertension, as well as diabetes, but may be considered for male infertility as well. CoQ10 levels can be quantified in semen, where its concentration is often linked with sperm count and sperm motility or movement. In a study of 228 men with unexplained infertility, half were given 200 mg of ubiquinol (the reduced form of CoQ10) for 26 weeks. At the end of that period, the group receiving ubiquinol supplementation had significantly improved sperm density, motility (movement), and morphology (shape and size). In another study, supplementation of 287 infertile men with 300 mg orally twice daily for 12 months lead to a significant improvement in sperm quality. Food sources for CoQ10 include oily fish like salmon, organ meats, and whole grains.
Carnitine also provides energy for the sperm and contributes directly to sperm motility. It may also be involved in the successful maturation of sperm. A clinical study reported that 3 g of carnitine per day for three months was able to increase sperm motility and total number of sperm. The best food sources of carnitine are animal products like fish, beef, and poultry. While there are two forms — the d and l forms — only the l‑carnitine is active in the body and found in food.
Zinc is a mineral that is necessary for the normal functioning of the immune system as well as the male reproductive system. More than 200 enzymes as well as other mechanisms in the body require zinc. Food sources can include red meat, chicken, seafood, nuts, and beans. Zinc deficiency is associated with lower testosterone levels and sperm count, and an adequate amount ensures proper sperm movement and production. Zinc levels are generally lower in infertile men with diminished sperm count. In one study, supplementation with zinc sulfate of 24 mg for 45–50 days increased testosterone levels and sperm count.
For anyone who is looking forward to having a child, infertility can be devastating. Finding a licensed health-care practitioner to help guide and inform you through all of the different testing and processes is critical. It is also important to know that there are modifiable changes that can be made which will positively impact the sperm quality and numbers. Start by modifying your lifestyle to a clean, organic diet with a high emphasis on vegetables and fruits, and less on meats (especially red meat). Make sure to exercise in moderation, and if you smoke, find a way to quit. This could mean getting help from multiple areas and can include identifying the triggers that drive the smoking habit and trying to adjust those. Stress is often a big reason why people smoke, and being able to decrease stress may help make quitting a lot easier. Keeping scrotal temperature from increasing too high, by wearing boxers instead of briefs and avoiding hot tubs and baths, can also help increase sperm quality and numbers. The choice of supplements and their dosages that are included in your daily regimen should be guided and monitored by your naturopathic doctor or another licensed health-care practitioner.
1. Sharma R, Biedenharn K, et al. Lifestyle factors and reproductive health: taking control of your fertility. Reproductive Biology and Endocrinology. 2013;11:66
2. Mascarenhas M., Flaxman S. et al. National, regional, and global trends in infertility: a systematic analysis of 277 health surveys. PLoS Med. 2012;9(12); e1001356.
3. Hammen R. Studies on impaired fertility in man with special reference to the male. Copenhagen: Einar Munksgaard, 1944.
4. World Health Organisation. WHO laboratory manual for the examination of human semen and semen-cervical mucus interaction. Cambridge: Cambridge University Press, 1987.
5. Griffin E. Wilson D. Disorders of the Testes. In : Isselbacher K, Braunwald E, Wilson J, Martin B, et.al, eds. Harrison’s Principles of Internal Medicine. 13th ed. New York, McGraw Hill. 1994:2006-2017.
6. Dunson D, Baird D, Colombo B. Increased infertility with age in men and women. Obstet Gynecol. 2004;103:51-56.
7. Kimberly L, Case A, et al. Advanced reproductive age and fertility. Int J Gynaecol Obstet. 2012;117:95-102.
8. Varshini J, Srinag BS, Kalthur G, Krishnamurthy H, Kumar P, Rao SB, Adiga S. Poor sperm quality and advancing age are associated with increased sperm DNA damage in infertile men. Andrologia. 2012;44(Suppl 1):642-649.
9. Wong W, Zielhuis G, Thomas C, et al. New evidence of the influence of exogenous and endogenous factors on sperm count in man. Eur J Obstet Gynecol Reprod Biol. 2003;110:49-54.
10. Mendiola J, Torres-Cantero A, et al. A low intake of antioxidant nutrients is associated with poor semen quality in patients attending fertility clinics. Fertil Steril. 2010;93:1128-1133.
11. Sallmen M, Sandler D, Hoppin J, Blair A, Baird D. Reduced fertility among overweight and obese men. Epidemiology. 2006;17:520-523.
12. Magnusdottir E, Thorsteinsson T, Thorsteinsdottir S, Heimisdottir M, Olafsdottir K: Persistent organochlorines, sedentary occupation, obesity and human male subfertility. Hum Reprod. 2005;20:208-215.
13. Martini A, Tissera A et al. Overweight and seminal quality: a study of 794 patients. Fertil Steril. 2010;94:1739-1743.
14. Chavarro J, Toth T, et al. Body mass index in relation to semen quality, sperm DNA integrity, and serum reproductive hormone levels among men attending an infertility clinic. Fertil Steril. 2010;93:2222-22231.
15. Wise L, Cramer D, Hornstein M, Ashby R, Missmer S. Physical activity and semen quality among men attending an infertility clinic. Fertil Steril. 2011; 95:1025-1030.
16. Vaamonde D, Da Silva-Grigoletto M, et al. Response of semen parameters to three training modalities. Fertil Steril. 2009;92:1941-1946.
17. Kulikauskas V, Blaustein D, Ablin R. Cigarette smoking and its possible effects on sperm. Fertil Steril. 1985;44:526-528.
18. Palan P, Naz R. Changes in various antioxidant levels in human seminal plasma related to immunoinfertility. Arch Androl. 1996; 36:139- 143.
19. Krause W, Hamm K, Weissmuller J. The effect of DDT on spermatogenesis of the juvenile rat. Bull Environ Contam Toxicol. 1975;14:171- 179.
20. Mehrpour O, Karrari P, et al. Occupational exposure to pesticides and consequences on male sperm and fertility; A review. Toxicol Lett. 2014, Jan. [Epub ahead of print].
21. Dickman M, Leung C, Leung M. Hong Kong male subfertility links to mercury in human hair and fish. Sci Total Environ. 1998;214:165-174.
22. Gennart J, Buchet J, Roels H, et al. Fertility of male workers exposed to cadmium, lead or manganese. Am J Epidemiol. 1992;135:1208- 1219.
23. Turk S, Mandar R, et al. Male infertility: Decreased levels of selenium, zinc and antioxidants. J Trace Elem Med Biol. 2013, Dec. [Epub ahead of print].
24. Mancini A, Balercia G. Coenzyme Q(10) in male infertility: physiopathology and therapy. Biofactors. 2011;37(5):374-80.
25. Safarinejad M, Safarinejad S, et al. Effects of the reduced form of coenzyme Q10 (ubiquinol) on semen parameters in men with idiopathic infertility: a double-blind, placebo controlled, randomized study. J Urol. 2012 Aug;188(2):526-31.
26. Safarinejad M. The effect of coenzyme Q10 supplementation on partner pregnancy rate in infertile men with idiopathic oligoasthenoteratozoospermia: an open-label prospective study. Int Urol Nephrol. 2012 Jun;44(3):689-700.
27. Goa K, Brodgen R. L-carnitine–a prelimi- nary review of its pharmacokinetics and its therapeutic use in ischemic cardiac disease and primary and secondary carnitine deficiencies in relationship to its role in fatty acid metabolism. Drugs. 1987;34:1-24.
28. Vitali G, Parente R, Melotti C. Carnitine supplementation in human idiopathic asthenospermia: clinical results. Drugs Exp Clin Res. 1995;21:157-159.
29. Favier A. Current aspects about the role of zinc in nutrition. Rev Prat. 1993;43:146-151.
30. Madding C, Jacob M, Ramsay V, Sokol R. Serum and semen zinc levels in normozoospermic and oligozoospermic men. Ann Nutr Metab. 1986;30:213-218.
31. Netter A, Hartoma R, Nahoul K. Effect of zinc administration on plasma testosterone, dihydrotestosterone, and sperm count. Arch Androl. 1981;7:69-73.