Testosterone
- Testosterone is an anabolic/androgenic hormone.
- Naturally produced in both men and women.
- Men: Testis and Adrenal Cortex
- Women: Adrenal Cortex
- Men normally have 10 times the resting serum testosterone concentration of women (Kraemer et al. 1991)
- Function
- Increased body growth
- Increased deposition of bone salts
- Adult levels stimulate epiphyseal plate closure
- Postnatal increases contributes to larger fibers from induction of muscle protein accretion
- SHBG Protein Binding
- More binding
- less free testosterone
- More binding
- Bioavailable Testosterone
- Increased by diets high in fat and protein
- Decreased in vegan diets (as is IGF-I)
- Decreased in diets high in carbs
- Decreased if soy protein is substituted for meat protein
- Habito RC, Montalto J, Leslie E, Ball MJ (2000). Effects of replacing meat with soyabean in the diet on sex hormone concentrations in healthy adult males. Br J Nutr. 84(4):557-63.
- Percentage free is 1.6 to 2.9 percent
Age | 20-40 | 40-50 | 50-60 | 70+ |
ng/ml | 400-1080 | 350-890 | 250-750 | 250-650 |
Testosterone Production
- Pituitary
- secretes Luteinizing Hormone (LH)
- affects Testes
- Cholesterol
- -> Pregnenolone
- -> Progesterone
- -> Aldosterone (mineral balance)
- -> Cortisol (stress)
- -> Androstenedione
- See Androstenedione's conversion below
- -> DHEA
- -> Androstenedione
- -> Estrone
- <-> Testosterone
- Free (active)
- decreases with SHBG (see below)
- Bound (inactive)
- Sex Hormone Binding Globulin (SHBG)
- Increases with age
- Increases with high estrogen
- brought about by blood sugar imbalance
- Sex Hormone Binding Globulin (SHBG)
- -> Dihydrotestoterone (DHT)
- -> Estradiol
- About one percent of testosterone is converted to estrogen
- Free (active)
- -> Androstenedione
- -> Progesterone
- -> Pregnenolone
Defects Resulting in Low Testosterone Symptoms
- Elevated Stress
- increases Cortisol
- suppresses Pituitary function
- decreases Luteinizing Hormone (LH)
- decreases testosterone production
- decreases Luteinizing Hormone (LH)
- 'Pregnenolone Steal' during chronic stress
- body favors Cortisol production
- over sex hormone production
- for survival
- body favors Cortisol production
- increased blood sugar (see below)
- suppresses Pituitary function
- increases Cortisol
- Blood Sugar Imbalances
- increases Progesterone -> Androstenedione -> Estrone
- Androstenedione is weak androgen
- 5 times weaker than testosterone
- competes with testosterone for binding on androgen receptors
- Higher Estrone to testosterone balance
- causes further insulin secretions in body
- normal testosterone
- Estrogen increases SHBG
- decreases free testosterone
- Androstenedione is weak androgen
- increases Progesterone -> Androstenedione -> Estrone
- Impaired Liver Detoxification
- impedes estrogen's breakdown
- half life of testosterone: 7 minutes
- half life of estrogen: hours
- increases estrogen : testosterone ratio
- impedes estrogen's breakdown
- Increased Dihydrotestoterone (DHT) production
- 5-delta Desaturase converts testosterone to DHT
- DHT has 10 times stronger infinity to receptor as compared to testosterone
- leads to receptor resistance to testosterone
- Dietary Deficiencies
- Zinc
- Low Zinc decreases testosterone production
- Low stomach acid decreases absorption of zinc
- Zinc
Diagnostics
- Get tested if you have symptoms of low testosterone
- Many defects possible, creating low testosterone symptoms
- many may not require hormone replacement
- normal testosterone but low testosterone symptoms
- Testosterone
- Male hormone panel includes
- total and free testosterone
- estrogens (estrione, estradiol, estriol)
- androstenedione
- sex hormone binding globulin
- DHEA
- DHT
- Luteinizing hormone.
- Cortisol
- Adrenal salivary panel
- Salivary testing can be used for male hormones
See more information on BPA and other Hormone Disruptors.