A recent study conducted across various ages in Israel found that testosterone levels
are declining over time for most age groups. From 2006 to 2019, average testosterone
levels at age 21 fell by 10%. 1 Previous research from the UK and the USA conducted
from 1970 to 2004 also indicated that average testosterone levels are declining. 2
Globally, sperm count declined by 50% to 60% from 1973 to 2011. 3
Most people know testosterone is essential, but not how important testosterone is for
men’s health. Testosterone plays a role in muscle growth, fertility, bone density, making
red blood cells, cognitive function & brain health, and lipid and carbohydrate
Why is testosterone declining? We don’t know the exact cause or causes, and likely
there are several reasons. Rates of chronic disease are increasing, and diseases like
diabetes, heart failure, osteoporosis, dyslipidemia, hypertension, type 2 diabetes, and
obesity have all been linked to low testosterone levels. 5 Physical activity levels continue
to decline, and being sedentary is associated with low testosterone levels in non-obese
men. 6 Testosterone levels decrease as waist circumference increases (a proximity
measure for visceral abdominal fat). 7
Testosterone is primarily made while we sleep, and lack of adequate sleep lowers
testosterone levels. 8 Americans are reporting higher stress levels due to the pandemic
and economic uncertainty. Chronic stress is associated with numerous hormone
alterations, including impaired testicular function. 9 Americans consume up to 65% of
their total energy intake from ultra-processed foods. Higher consumption of these high-
calorie, nutrient-poor, protein-poor foods is associated with lower blood testosterone
42% of Americans are deficient in Vitamin D, a vital hormone in making testosterone. 11
Many Americans lack other essential nutrients, like zinc and magnesium, that help
regulate testosterone production. 12 An area of concern that we are still learning about is
endocrine-disrupting chemicals (EDCs). Human observational studies link EDCs found
in cosmetic products, plastics, and drink water to lower testosterone levels. 13
At Nimbus, we take a holistic approach to testosterone optimization by combining
vitamin therapy, lifestyle medicine (nutrition, exercise, stress management, sleep
hygiene, etc.), and prescription medication to create a comprehensive plan to balance
and normalize testosterone levels. Get your male wellness kit today to start your
testosterone optimization journey!
1 Chodick G, Epstein S, Shalev V. Secular trends in testosterone- findings from a large state-
mandate care provider. Reprod Biol Endocrinol. 2020;18(1):19. Published 2020 Mar 9.
2 Nyante SJ, Graubard BI, Li Y, McQuillan GM, Platz EA, Rohrmann S, Bradwin G, McGlynn KA.
Trends in sex hormone concentrations in US males: 1988-
1991 to 1999-2004. Int J Androl. 2012;35:456–66.
3 Levine H, Jørgensen N, Martino-Andrade A, et al. Temporal trends in sperm count: a
systematic review and meta-regression analysis. Hum Reprod Update. 2017;23(6):646-659.
4 Tyagi V, Scordo M, Yoon RS, Liporace FA, Greene LW. Revisiting the role of testosterone: Are
we missing something?. Rev Urol. 2017;19(1):16-24. doi:10.3909/riu0716
5 Travison TG, Araujo AB, Kupelian V, O'Donnell AB, McKinlay JB. The relative contributions of
aging, health, and lifestyle factors to serum testosterone
decline in men. J Clin Endocrinol Metab. 2007;92:549–55.
6 Steeves JA, Fitzhugh EC, Bradwin G, McGlynn KA, Platz EA, Joshu CE. Cross-sectional
association between physical activity and serum testosterone levels in US men: results from
NHANES 1999-2004. Andrology. 2016;4(3):465-472. doi:10.1111/andr.12169
7 Hall SA, Esche GR, Araujo AB, et al. Correlates of low testosterone and symptomatic
androgen deficiency in a population-based sample. J Clin Endocrinol Metab. 2008;93(10):3870-
8 Su L, Zhang SZ, Zhu J, Wu J, Jiao YZ. Effect of partial and total sleep deprivation on serum
testosterone in healthy males: a systematic review and meta-analysis. Sleep Med. 2021;88:267-
9 Jóźków P, Mędraś M. Psychological stress and the function of male gonads. Endokrynol Pol. 2012;63(1):44-49.
10 Hu TY, Chen YC, Lin P, et al. Testosterone-Associated Dietary Pattern Predicts Low
Testosterone Levels and Hypogonadism. Nutrients. 2018;10(11):1786. Published 2018 Nov 16.
11 Holt R, Juel Mortensen L, Harpelunde Poulsen K, et al. Vitamin D and sex steroid production
in men with normal or impaired Leydig cell function. J Steroid Biochem Mol Biol.
12 Reider CA, Chung RY, Devarshi PP, Grant RW, Hazels Mitmesser S. Inadequacy of Immune
Health Nutrients: Intakes in US Adults, the 2005-2016 NHANES. Nutrients. 2020;12(6):1735.
Published 2020 Jun 10. doi:10.3390/nu12061735
13 Chen SY, Hwang JS, Sung FC, et al. Mono-2-ethylhexyl phthalate associated with insulin
resistance and lower testosterone levels in a young population. Environ Pollut. 2017;225:112-