Testosterone occurs in two distinct forms in the body: free and bound. Free testosterone is useful and functional; bound testosterone is less so. Ironically, as a man’s production of testosterone declines, the amounts of sex hormone-binding globulin (SHBG) often increase. Thus, remaining testosterone is increasingly bound by this protein, rendering already dwindling supplies less effectual. When assessing a man’s hormone status, clinicians frequently measure “total testosterone,” which includes free testosterone and testosterone bound to SHBG. It is free testosterone, however, that is the most relevant measure of a man’s testosterone status.
Just as free testosterone levels are declining with age, another detrimental process is taking place. Levels of the enzyme aromatase tend to increase with age (and increasing belly fat mass). Aromatase converts testosterone to estrogen, further depleting free testosterone levels and increasing estrogen levels. As a result, men become even more susceptible to complaints related to diminished testosterone levels, while becoming more prone to suffer the adverse effects of too much estrogen, which can include prostate enlargement and even increased risk for prostate cancer. This is termed ‘estrogen dominance’. To confirm this, test for estradiol with a 20-30 pg/ml range being considered normal.
Estrogen dominance and high levels of aromatase are aggravated when cortisol is constantly elevated – as it often is in the sleep-deprived and chronically-stressed. Cortisol is catabolic, while testosterone is anabolic. Excessive levels of cortisol produce insulin resistance, fat gain, and muscle wasting, while testosterone promotes muscular hypertrophy and lean mass gains. Cortisol contributes to metabolic syndrome, while testosterone helps alleviate it.
Add chronically high levels of insulin and insulin resistance to the mix. Dietary choices drive this with excess carbohydrate fueling the process of driving testosterone levels down and increasing the degree of estrogen domination.
One additional and often overlooked contributor to the disturbance of testosterone is hemochromatosis. Iron overload not only causes sex hormone levels (testosterone) to decline but many other hormones as well (thyroxin in the thyroid gland, insulin in the pancreas, hormones in the pituitary gland and adrenal glands)1. Low testosterone accompanied by low thyroid should be a major signal that iron overload may be involved.
It would seem that administration of testosterone would be a ready solution. It may be for some but often only for a time. The reason being that the aromatase-insulin-hemochromatosis engine is relentless. More free testosterone? More aromatase = more estradiol. Hyper-insulin conquers all. Back where you started.
It is possible to boost the availability of beneficial free testosterone and offset detrimental increases in estrogen using botanical extracts. This integrative approach to male aging may dramatically improve conditions ranging from flagging energy levels to fading libidos while simultaneously decreasing the chances that a man will fall victim to prostate enlargement or cancer.
Maca (Lepidium meyenii)
Maca has been used among indigenous people in the Andes region for centuries. Maca is a vegetable in the same family as broccoli. It is a reputed aphrodisiac and fertility enhancer. Research has shown there is sound scientific basis for this belief. Maca improves libido while enhancing sperm production and sperm motility, according to recent research. And it achieves this without affecting male sex hormone levels2,3.
Interestingly, maca has also been shown to significantly improve glucose tolerance, antioxidant levels, and lipid profiles among rodents with a hereditary tendency to develop abnormally high blood triglyceride levels. Despite their genetically abnormal lipid profiles, rats given maca while consuming a sugar-rich diet experienced significant improvements in a number of parameters related to cardiovascular disease risk, including lower total cholesterol and low-density lipoprotein (LDL) levels, and increased levels of the potent natural antioxidants, glutathione, superoxide dismutase, and glutathione peroxidase.
Muira puama (Ptychopetalum olacoides)
Muira puama is reputed to enhance erectile function and orgasm in aging men suffering the effects of fatigue or age-related complaints.31 In one study of 262 men suffering from poor sexual desire, more than 60% reported improvements with muira puama. Additionally, more than 50% of the men reported that muira puama improved their ability to attain an erection4. While muira puama’s mechanism of action remains unknown, it is interesting to note that the plant contains sterols—the building blocks of sex hormones such as testosterone.
Muira puama is marketed in Brazil as a “body stimulant, energetic, tonic, and aphrodisiac,” in combination with several other herbal extracts, including ginger and guarana (a source of caffeine)5. Research on human volunteers demonstrated that this cocktail of ingredients was safe and well tolerated. “No severe adverse reactions or haematological and biochemical changes were reported,” researchers concluded.
Chrysin is a natural flavone found in numerous plants, but especially in passionflower (Passiflora incarnata). Research suggests that chrysin reduces anxiety by binding with receptors in the brain that are also targeted by benzodiazepines. But chrysin’s primary benefit to human sexuality may derive from its ability to block aromatization.43
Aromatization is a chemical transformation that takes place in the body, whereby testosterone or other androgen hormones are converted to estrogens by the aromatase enzyme. Aromatase inhibitors are beneficial because they prevent the loss of free testosterone and the buildup of potentially dangerous estrogens. Although chrysin has low oral bioavailability,its bioavailability may be significantly enhanced by co-administration with the pepper extract, piperine.The combination of chrysin with piperine may thus represent an important botanical strategy to optimize free testosterone levels and minimize excess estrogen levels by blocking aromatization.
Studies suggest vitamin D can increase testosterone concentrations in men. A German research team , for example, gave 54 overweight but otherwise healthy men either a placebo (23 men) or 3,333 IU vitamin D per day (31 men) for 12 months. When the men entered the study, they were vitamin D deficient (average of 30 nmol/L or 12 ng/mL). All the men also participated in a structured weight loss program.
At the end of 12 months, the men who took vitamin D showed an increase in levels to an average of 86 nmol/L (34.5 ng/mL). These same men also had a small but significant increase in mean testosterone levels as well:
- Total testosterone, from 10.7 to 13.4 nmol/L
- Bioactive testosterone (free T plus T loosely bound to albumin), from 5.21 to 6.25 nmol/L
- Free testosterone, from 0.222 nmol/L to 0.267 nmol/L
The men who took placebo didn’t show any significant changes in testosterone or vitamin D. Based on these findings, the authors concluded that vitamin D supplements might increase levels of testosterone7.
- Gonzales GF, Cordova A, Gonzales C, et al. Lepidium meyenii (Maca) improved semen parameters in adult men. Asian J Androl. 2001 Dec;3(4):301-3. https://www.ncbi.nlm.nih.gov/pubmed/11753476
- Gonzales GF, Cordova A, Vega K, et al. Effect of Lepidium meyenii (MACA) on sexual desire and its absent relationship with serum testosterone levels in adult healthy men. Andrologia. 2002 Dec;34(6):367-72. https://www.ncbi.nlm.nih.gov/pubmed/12472620
- Rowland DL, Tai W. A review of plant-derived and herbal approaches to the treatment of sexual dysfunctions. J Sex Marital Ther. 2003 May-Jun;29(3):185-205. https://www.ncbi.nlm.nih.gov/pubmed/12851124
- Oliveira CH, Moraes ME, Moraes MO, et al. Clinical toxicology study of an herbal medicinal extract of Paullinia cupana, Trichilia catigua, Ptychopetalum olacoides and Zingiber officinale (Catuama) in healthy volunteers. Phytother Res. 2005 Jan;19(1):54-7. https://www.ncbi.nlm.nih.gov/pubmed/15798997
- Moon YJ, Wang X, Morris ME. Dietary flavonoids: effects on xenobiotic and carcinogen metabolism. Toxicol In Vitro. 2006 Mar;20(2):187-210. https://www.ncbi.nlm.nih.gov/pubmed/16289744
- Horm Metab Res. 2011 Mar;43(3):223-5. doi: 10.1055/s-0030-1269854. Epub 2010 Dec 10. Effect of vitamin D supp estosterone levels in men. https://www.ncbi.nlm.nih.gov/pubmed/21154195