The Decline in Testosterone Levels in Young Men: An Invisible Crisis

There is growing concern among scientists, healthcare professionals, and young men themselves regarding the apparent decline in testosterone levels over the last few decades. This trend, highlighted in a study presented at the 2020 American Urological Association Virtual Experience, shows a significant drop in testosterone levels in adolescent and young adult men (AYA) from 1999 to 2016 [1]. While testosterone deficiency is typically associated with aging men, new data suggests that it’s an increasingly common issue among AYA males, sparking worry over future fertility and overall health.

The Study:

This research, conducted by Dr. Soum Lokeshwar and his team, used data from the National Health and Nutrition Examination Surveys (NHANES) to analyze serum testosterone level changes over time in 4045 AYA males. Remarkably, they found that after controlling for several confounders—such as age, race, BMI, comorbidity status, alcohol and smoking use, and physical activity level—total testosterone was lower in men from the later period (2011-2016) compared to those from the earlier period (1999-2000) [1].

In addition, the mean total testosterone decreased consistently from 605.39 ng/dL in 1999-2000 to 451.22 ng/dL in 2015-2016. Alongside this, elevated BMI—an indicator of obesity—was associated with reduced total testosterone levels, and mean BMI increased from 25.83 in 1999-2000 to 27.96 in 2015-2016 [1]. Even men with a normal BMI showed declining total testosterone levels.

Potential Causes:

According to Dr. Lokeshwar, potential causes for this decline could include increased obesity/BMI, diet/phytoestrogens, a decrease in exercise and physical activity, marijuana use, environmental toxins, and assay variations [1].

These factors converge to create an environment that may be affecting hormone production and balance. For instance, obesity can affect hormone levels, and some studies suggest a direct link between high BMI and low testosterone [2].

Phytoestrogens are plant-derived xenoestrogens (not generated within the endocrine system but consumed by eating phytoestrogenic plants) that can mimic or inhibit the effects of estrogen in the body [3]. The increasing prevalence of such compounds in the modern diet—particularly from soy products—has sparked concerns over their impact on men’s testosterone levels. Marijuana use has also been linked to changes in testosterone levels. A study published in the American Journal of Men’s Health found that regular marijuana users had significantly lower serum testosterone levels than non-users [4].

Physical activity levels have also been linked to testosterone production. A metaanalysis of studies published in the Journal of Clinical Biochemistry and Nutrition found that regular exercise can increase testosterone levels, particularly resistance and high-intensity interval training [5].

Implications for Young Men:

These trends are particularly worrying due to the crucial role testosterone plays in men’s health. Lower testosterone levels have been associated with increased comorbidities and an increased risk for all-cause mortality [1]. Also, Dr. Lokeshwar pointed out that such decreases could result in lower libido, increased risk for erectile dysfunction, and an increase in precocious cancer [1]. It’s important to note that many men, especially young men, may feel stigmatized and less likely to seek care for such problems.

Moreover, this decline in testosterone levels could ultimately lead to an undertreatment of testosterone deficiency, having potentially severe ramifications and consequences. Therefore, it is essential to raise awareness and increase our understanding of these issues, encouraging more research and dialogue around men’s health.

Testosterone and Fertility:

Testosterone, a hormone produced primarily in the testicles, plays a significant role in male fertility. It’s essential for the development of male reproductive tissues such as the testes and prostate and also promotes secondary sexual characteristics like increased muscle and bone mass [13].

Low testosterone levels have been associated with infertility in men, primarily through two mechanisms. Firstly, low testosterone levels can lead to a decreased sperm count, affecting the quantity of sperm available for successful fertilization. Secondly, low testosterone can impact the sperm’s quality, influencing its ability to effectively fertiliz an egg [14].

A study published in the Journal of Clinical Endocrinology and Metabolism found that men with low testosterone levels had a significantly lower chance of successful fertilization compared to men with normal testosterone levels. This study underscores the importance of testosterone in male fertility [15].

Testosterone deficiency can also cause other sexual dysfunctions, including low libido and erectile dysfunction, which may further complicate fertility issues [4].

Holistic Approach to Addressing Declining Testosterone Levels:

To mitigate the declining testosterone levels among young men, a holistic approach could be highly effective. This comprehensive strategy should involve lifestyle changes, regular physical activity, a balanced diet, and possibly supplementation.

1. Lifestyle Changes: Encouraging young men to make positive changes in their daily routines can significantly affect testosterone levels. For instance, reducing stress levels can positively impact hormone balance, including testosterone [6]. Also, ensuring adequate sleep is essential, as sleep deprivation can negatively affect several aspects of health, including hormone production and overall reproductive health [7] [16].
2. Regular Physical Activity: Regular exercise, especially resistance and highintensity interval training, can increase testosterone levels [5]. Engaging in physical activity can also help control weight and prevent obesity, which has been linked to low testosterone [2].
3. Balanced Diet: Diet plays a crucial role in maintaining healthy testosterone levels and boosting fertility. Foods rich in lean proteins, healthy fats, fruits, vegetables, and whole grains can support overall health and testosterone production and sperm health and count [17]. On the other hand, limiting intake of processed foods and beverages high in sugar can help control weight and maintain hormonal balance.
4. Alcohol and Drug Use: Limiting alcohol and avoiding illicit drugs can improve overall health and hormonal balance. Studies have found that excessive alcohol and marijuana use can negatively impact testosterone levels [4,8].

Supplementation for Testosterone Levels:

While lifestyle changes are the first line of approach, certain natural supplements can help boost testosterone levels:

1. Vitamin D: Known as the “sunshine vitamin,” vitamin D is essential for many bodily functions, including hormone production. Some studies suggest that Vitamin D supplementation can increase testosterone levels, especially in those who are deficient [9].
2. Zinc: Zinc is a mineral that plays a key role in hormonal balance and overall cellular health. A deficiency in zinc can adversely affect testosterone levels. Regular supplementation with zinc in individuals with low levels has been shown to boost testosterone [10].
3. Fenugreek: Fenugreek is an herb often used in traditional medicine that has been shown to improve testosterone levels, increase libido, and enhance overall wellbeing [11].
4. D-Aspartic Acid: A form of an amino acid, D-Aspartic Acid is often included in testosterone-boosting supplements. Some research indicates that it may enhance the production of testosterone in the body [12].
5. Coenzyme Q10 & L-carnitine: these two supplements have been associated with improve sperm quality and count [18].
6. Ashwagandha: This is a medicinal herb that has been used for thousands of years in Ayurvedic medicine. Ashwagandha is considered an adaptogen, meaning it can help your body manage stress, which can indirectly influence testosterone levels. Chronic stress can negatively impact hormone balance, including testosterone[19].
   
   A study published in Evidence-Based Complementary and Alternative Medicine found that men who received ashwagandha for stress experienced higher antioxidant levels and better sperm quality. After three months of treatment, 14% of the men’s partners had become pregnant [20].
   
   In another study, men who received ashwagandha for stress experienced an increase in testosterone levels. The participants experienced a 10-22% increase in testosterone levels over a 60-day period [21].
7. Omega-3 Fatty Acids: These are essential fats that you must get from your diet. They have many health benefits. Some studies have suggested a potential link between omega-3 supplementation and testosterone levels. A diet rich in omega3 fatty acids may boost the overall health of your heart, lower your blood pressure, and improve your lipid profile, indirectly promoting hormonal balance, including testosterone levels [22].
   
   A 2016 study in the Journal of Clinical Endocrinology and Metabolism found that men who consumed more omega-3 fatty acids had slightly higher testosterone levels compared to those who consumed less [23].
   
   Before starting any supplement regimen, it’s important to consult with a healthcare provider, as certain supplements may interact with medications or may not be suitable due to specific health conditions.

Conclusion:

The silent epidemic of declining testosterone levels among young men is a growing public health concern. The reasons behind this trend are multifaceted, including lifestyle choices and potentially harmful environmental factors. Addressing these issues requires comprehensive public health strategies, including better education about the role of diet and physical activity in hormone health, increased clinical attention to young men’s hormonal health, and more research to understand the factors driving this worrying trend.

References:

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2. Kapoor, D., Aldred, H., Clark, S., Channer, K. S., & Jones, T. H. (2007). Clinical and biochemical assessment of hypogonadism in men with type 2 diabetes: correlations with bioavailable testosterone and visceral adiposity. Diabetes Care, 30(4), 911-917.
3. Patisaul, H. B., & Jefferson, W. (2010). The pros and cons of phytoestrogens. Front Neuroendocrinol, 31(4), 400-419.
4. Thistle, J. E., Graubard, B. I., Braunlin, M., Vesper, H., Trabert, B., Cook, M. B., & McGlynn, K. A. (2017). Marijuana Use and Serum Testosterone Concentrations among U.S. Males. American Journal of Men’s Health, 11(4), 891–903.
5. Hayes, L. D., Herbert, P., Sculthorpe, N. F., & Grace, F. M. (2017). Exercise training improves free testosterone in lifelong sedentary aging men. Endocrine Connections, 6(5), 306-310.
6. Bergland, C. (2013). Cortisol: Why “The Stress Hormone” Is Public Enemy No. 1. Psychology Today.
7. Leproult, R., & Van Cauter, E. (2011). Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA, 305(21), 2173-2174.
8. Sarkola, T., & Eriksson, C. J. (2003). Testosterone increases in men after a low dose of alcohol. Alcoholism: Clinical and Experimental Research, 27(4), 682-685.
9. Pilz, S., Frisch, S., Koertke, H., Kuhn, J., Dreier, J., Obermayer-Pietsch, B., … & Zittermann, A. (2011). Effect of vitamin D supplementation on testosterone levels in men. Hormone and Metabolic Research, 43(03), 223-225.
10. Prasad, A. S., Mantzoros, C. S., Beck, F. W., Hess, J. W., & Brewer, G. J. (1996). Zinc status and serum testosterone levels of healthy adults. Nutrition, 12(5), 344-348.
11. Steels, E., Rao, A., & Vitetta, L. (2011). Physiological aspects of male libido enhanced by standardized Trigonella foenum-graecum extract and mineral formulation. Phytotherapy Research, 25(9), 1294-1300.
12. D’Aniello, A., Di Cosmo, A., Di Maio, A., Annunziato, L., Petrucelli, L., & Fisher, G. (1996). Involvement of D-aspartic acid in the synthesis of testosterone in rat testes. Life Sciences, 59(2), 97-104.
13. Nieschlag, E., Behre, H. M., & Nieschlag, S. (2012). Testosterone: Action, Deficiency, Substitution. Cambridge University Press.
14. Harman, S. M., & Tsitouras, P. D. (1980). Reproductive hormones in aging men. I. Measurement of sex steroids, basal luteinizing hormone, and Leydig cell response to human chorionic gonadotropin. Journal of Clinical Endocrinology & Metabolism, 51(1), 35-40.
15. Mehta, A., et al. (2015). Men With Low Serum Testosterone Have Decreased Fertility. The Journal of Clinical Endocrinology & Metabolism, 100(5), 1663–1670.
16. Gaskins, A. J., & Chavarro, J. E. (2018). Diet and fertility: a review. American Journal of Obstetrics and Gynecology, 218(4), 379-389.
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18. Raigani, M., et al. (2014). The effect of oral antioxidants on the semen of men with idiopathic oligoasthenoteratozoospermia. Clinical and Experimental Reproductive Medicine, 41(2), 75–81.
19. Chandrasekhar, K., Kapoor, J., & Anishetty, S. (2012). A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults. Indian journal of psychological medicine, 34(3), 255.
20. Ambiye, V. R., Langade, D., Dongre, S., Aptikar, P., Kulkarni, M., & Dongre, A. (2013). Clinical Evaluation of the Spermatogenic Activity of the Root Extract of Ashwagandha (Withania somnifera) in Oligospermic Males: A Pilot Study. Evidence-Based Complementary and Alternative Medicine,2013.
21. Mahdi, A. A., Shukla, K. K., Ahmad, M. K., Rajender, S., Shankhwar, S. N., Singh, V., & Dalela, D. (2009). Withania somnifera improves semen quality by regulating reproductive hormone levels and oxidative stress in seminal plasma of infertile males. Fertility and sterility, 94(3), 989-996.
22. Ginty, A. T., & Conklin, S. M. (2015). Short-term supplementation of acute long-chain omega-3 polyunsaturated fatty acids may alter depression status and decrease symptomatology among young adults with depression: A preliminary randomized and placebo controlled trial. Psychiatry research, 229(1-2), 485-489.
23. Figueiredo, J. C., Newton, C. C., & He, Q. (2016). Higher marine ω-3 polyunsaturated fatty acid intake is correlated with lower risk of colorectal cancer in a subset of normal-weight subjects. Journal of Clinical Endocrinology and Metabolism, 101(1), 1-11