Falling Sperm Counts
You may have heard recent news reports about the falling sperm counts in men across the western world. These reports came from an analysis of 185 studies between 1973 and 2011 which found that the sperm counts of men in America, Australia, New Zealand and Europe have decreased by over 50% in the last 40 years.
It is estimated that one in six couples are unable to conceive with about half of these cases being due to poor sperm quality or quantity. Unexplained infertility is also an increasingly common diagnosis. The fact that the decline in sperm counts and fertility are seen in Western countries strongly suggests that aspects of the western diet, lifestyle and environment are playing a causal role in this trend (1).
The following are all factors that are associated with reduced fertility in men:
Age – advanced paternal age is associated with reduced semen volume as well as reduced sperm count, motility and morphology (2,3). Older fatherhood is also associated with lower pregnancy rates, increased rates of still births and spontaneous abortion (independent of maternal age) and of the offspring developing autism, bipolar disorder and schizophrenia (4).
Screen Time – healthy young men who watch more than 20 hours of television a week have almost half the sperm count of men who watch very little TV (5).
Exercise – men who do more than 15 hours of moderate to vigorous exercise a week have sperm counts that are over 70% higher than men who exercise very little (6).
Mobile Phones and Wifi – evidence is mixed but exposure to electromagnetic radiation from mobile phones and internet usage may reduce sperm quality, quantity and motility (7,8).
Stress – psychological stress has a negative effect on concentration, appearance, and ability of sperm to fertilize an egg. Unemployed men also have sperm of lower quality than employed men, regardless of how stressed they are (9).
Endocrine Disruptors – these are present in food, textiles, drugs, cleaning products, plastic packaging, toys and cosmetics. A direct link has been found between exposure to endocrine disrupting chemicals from industrial products and impaired sperm function with reduced ability to fertilise an egg. The anti-bacterial agent triclosan, which is found in many toothpastes, soaps and cleaning products, is one of the culprits (10).
Aluminium – the higher the aluminium content of semen the lower the sperm count. To reduce exposure to aluminium use stainless steel or ceramic cook ware and avoid aluminium saucepans as much as possible. Avoid drinks in aluminium cans (11).
Sunscreens – chemicals that filter UV rays in many sunscreens interfere with the function of sperm cells with some mimicking female hormones (12).
BPA – BPA is a ubiquitous environmental contaminant, resulting from manufacturing, use, disposal and degradation of plastic. There is growing evidence from research on laboratory animals, wildlife, and humans that BPA produces an endocrine disrupting effect and adversely affects male reproductive function. BPA has been found to produce several defects in the embryo, such as feminization of male fetuses, atrophy of the testes, increased prostate size, and alteration of sperm parameters such as sperm count, motility, and density. Men exposed to BPA at work had abnormal semen parameters, reduced libido and erectile and ejaculatory difficulties (13).
Sexually Transmitted Diseases – there may be an association between some STDs and male infertility (14) so practicing safe sex and having regular sexual health check ups are vital.
Heat – if the testicles are regularly too warm sperm production is impaired. Anything that traps heat in the area should be avoided. Examples include wearing tight fitting or synthetic underwear, riding a bike or sitting in a chair or car for long periods of time, saunas, hot tubs and water beds. Wear loose fitting, cotton clothing and get up and walk around regularly if you spend a lot of time sitting down.
There are some factors affecting fertility that are hard to avoid or control. However, there are many dietary and lifestyle changes that can be made to increase your chances of having a healthy baby and healthy hormone levels. In conclusion, move your body and avoid chemicals from food, packaging and the environment as far as possible. Oh and keep cool!
- 1. Levine H, Jørgensen N, Martino-Andrade A, et al. Temporal trends in sperm count: a systematic review and meta-regression analysis. Human Reproduction Update, July 2017; 1;23(4):371-389.
- 2. Johnson SL, Dunleavy J, Gemmell NJ et al. Consistent age-dependent declines in human semen quality: a systematic review and meta-analysis. Ageing Res Rev. 2015 Jan;19:22-33
- 3. Belloc S, Hazout A, Zini A et al. .How to overcome male infertility after 40: Influence of paternal age on fertility. Maturitas. 2014 May;78(1):22-9.
- 4. Nybo-Andersen AM, Urhoj SK. Is advanced paternal age a health risk for the offspring? Fertil Steril. 2017 Feb;107(2):312-318.
- 5. Gaskins AJ, Mendiola J, Afeiche M et al. Physical activity and television watching in relation to semen quality in young men. British Journal of Sports Medicine, 2013;
- 6. Lawson G, Fletcher R. Delayed Fatherhood. J Fam Plan Reprod Health Care. 2014 Oct;40(4):283-8.
- 7. Adams JA, Galloway TS, Mondal D et al. Effect of mobile telephones on sperm quality: a systematic review and meta-analysis. Environ Int. 2014 Sep;70:106-12
- 8. Yildirim ME, Kaynar M, Badem H et al. What is harmful for male fertility: cell phone or the wireless Internet? Kaohsiung J Med Sci. 2015 Sep;31(9):480-4.
- 9. Janevic T, Kahn LG, Landsbergis P, Cirillo PM et al. Effects of work and life stress on semen quality. Fertility and Sterility, 2014; Aug;102(2):530-8
- 10. Schiffer C, Müller A, Egeberg DL et al. Direct action of endocrine disrupting chemicals on human sperm. 2014 European Society for Human Reproduction and Embryology. 2014
- 11. Klein JP, Mold M, Mery L et al. Aluminium content of human semen: implications for semen quality. Reproductive Toxicology, 2014; Dec;50:43-8.
- 12. The Endocrine Society. “Some sunscreen ingredients may disrupt sperm cell function.” ScienceDaily. ScienceDaily, 1 April 2016.
- 13. Manfo FP, Jubendradass R, Nantia EA et al. Adverse effects of bisphenol A on male reproductive function. Rev Environ Contam Toxicol. January 2014. 228:57-82
- 14. Fode M, Fusco F, Lipshults L, Weidner W. Sexually Transmitted Disease and Male Infertility: A Systematic Review. Eur Urol Focus. 2016 Oct;2(4):383-393.