The Testosterone Decline
In the last decade, we have seen a sharp rise in marketing ads targeting men with ‘Low T’ featuring a slump-shouldered man on the screen with symptoms in bold font leaping in front of him: low libido, fatigue, infertility, erectile dysfunction, osteoporosis, reduced muscle mass and depressed mood.
After 30 years of age, normal male aging has a gradual testosterone decrease of approximately 1% per year, but recent trends show a much sharper decline compared with just a few decades ago. While there are a variety of known risk factors (obesity, opiate pain medications, blood sugar dysregulation, smoking and a sedentary lifestyle1 ), there are a variety of environmental factors that also contribute to low testosterone.
The shift in increased rates of testosterone decline has been well documented. The Baltimore Longitudinal Aging Study examined over 40 years of data and found that samples taken from men in 1965-1971 had 40% higher testosterone levels than samples collected from men in 1985-19952. Testosterone levels were found to have declined at about 1.2% per year, approximately 17% lower in American men from 1987 compared to 20043. This data is concerning for a variety of reasons including the parallel drop in fertility rates that accompanies decreased testosterone levels.
As with most health chronic conditions, the contributing factors are multifactorial and involve one, if not many, of the foundations of health: nutrition, exercise, genetics, lifestyle, stress management, hydration, elimination, sleep and environmental factors. While most integrative practitioners are fairly comfortable talking about the majority of foundations, environmental factors are less often prioritized in treatment plans. When it comes to men’s hormonal health, exposure to toxins at any point in the lifespan, including when they are in utero as well as during prepubescent and pubescent years, can have a significant impact on their ability to make testosterone later in life—during their reproductive years and beyond.
There are numerous commonplace environmental exposures that contribute to the decline of testosterone. Due to short nature of this article, we will focus in on two plasticizers; phthalates and bisphenols. One study that followed children from their first trimester in utero until 14 years of age found that as urinary levels of phthalates and BPA increased, testosterone levels decreased4. The NHANES study found that higher phthalates levels were associated with both a 24-34% drop in testosterone among boys and similar declines in males 40-60 years old5. Another study found that increased phthalate body burden was associated with a 20% reduction in male fertility, which is directly tied to testosterone production6.
Reducing exposure to phthalates and bisphenols is a great way to reduce toxic body burden and help restore healthy testosterone levels. First, try to limit your overall exposure to plastics (food containers, cans, food, packaging, etc.). Read labels and avoid all personal care products (cologne, shaving creams, shampoo, etc.) with phthalates. Whether at the grocery or gardening store, try to reduce pesticide exposure by shopping organically and forgoing the lawn pesticides. These are just a few of the many ways to reduce your exposures. You are welcome to reference previous articles “Natural Personal Care: The Importance of Going Clean I & II” for additional sources of phthalates and bisphenols. Hopefully these additional tools will help you identify and eliminate impediments to robust health for your male patients!
- Chiles, KA, Hypogonadism and erectile dysfunction as harbingers of system disease. Transl Androl Urol. 2016 Apr;5(2):195-200.
- Harman et al. Longitudinal effects of aging on serum total and free testosterone levels in healthy men. Baltimore Longitudinal Study of Aging. J Clin Endocrinol Metab. 2001 Feb;86(2):724-31.
- Travinson, TG. A population-level decline in serum testosterone levels in American men. J Clin Endocrinol Metab. 2007 Jan;92(1):196-202.
4.Ferguson, KK et al. Prenatal and peripubertal phthalates and bisphenol A in relation to sex hormones and puberty in boys. Reprod Toxicol. 2014 Aug;47:70-6.
- Meeker, JD & Ferguson, KK. Urinary phthalate metabolites are associated with decreased serum testosterone in men, women, and children from NHANES 2011-2012. J Clin Endocrinol Metab. 2014 Nov;99(11):4346-52.
- Buck, GM, et al. Urinary bisphenol A, phthalates, and couple fecundity: the Longitudinal Investigation of Fertility and the Environment (LIFE) Study. Fertil Steril. 2014 May;101(5):1359-66.
By Tina Beaudoin ND