Cordyceps Sinensis - Another Supplemental Non-Starter: Human Data Shows No Increase in Testosterone, No Strength Gains, No Improvements in Body Composition.

Image 1: As it turns out it's not necessary you start eating parasites (img nepaliproducts.com)

In view of the public attention adaptogens have gotten, ever since everyone is self-diagnosing him- / herself with "Central Fatigue Syndrom", I assume you will be aware that the parasitic fungus, Cordyceps sinensis (CS) that is found on larvae of Lepidoptera, and has been used for centuries in traditional Chines medicine as a tonic, has lately been marketed as powerful modulator of the hypothalamus-thyroid-pituitary axis (HTPA). Extracts from cordyceps have in fact been shown to have various biological and pharmacological actions on the liver, the kideys, the endocrine and the vascular system. It appears to stimulate erythropeoiesis (production of red blood cells) and haemopoiesis (formation of blood cellular compounds), and it exhibits immunomodulatory and anti-tumor activities.

Within the health and fitness community Cordyceps sinensis has yet been touted as "natural HCG" (human chorionic gonadotropin), because, just like the latter, it stimulates the release of luteinizing hormone and thus testosterone secretion in rodent models (mice and rat; cf. Huang. 2001; HSU. 2003; Huang. 2004). Not long ago, scientists have identified cordycepin as the active ingredient in the parasite extract - an ingredient, which, according to Pan et al., does not only stimulate steriodogenesis, but also exhibits anti-cancer effects by inducing apoptosis in MA-10 mouse Leydig tumor cells (Pan. 2011).

Illustration 1: Training protocol the subjects in the study performed  3x à week for a total of 8 weeks.

With its endocrine and haematopoietic effects, cordyceps looks like the perfect substitute for what you may call the "Tour de France performance package", i.e. the combination of testosterone (e.g. Landis) and erythropoietin (e.g. Riis). Consequently, one should expect that an 8-week (3 training sessions per week)randomized double-blind place-controlled study with sixteen previously not resistance-trained young volunteers (male, age: 19-25; BMI: 24kg/m²; body fat: 14.65%), like the one performed by Hsu et al. at the Graduate Institute of Sports Science at the National Taiwan Sports University, should show at least some measurable effects on strength and muscle gains and/or body composition of the subjects.

Figure 1: Muscle strength as maesured by 1RM after 8 weeks of strength training with (CS) and without (PL) Cordyceps sinensis supplementation (data based on Hsu. 2011).

Figure 1, however, shows no greater strength improvements in the Cordyceps sinensis (6 caps à 400mg of an extract containing 0.33% soluble protein, 5.81% sugars, 5.92µmol/g adenosine derivatives (5.92 µmol/g), 1.23µmol/g cordycepin and 8.81 µmol/g ergosterol) supplemented strength trainees (CS) compared to the subjects in the placebo group (PL). And even the +7% greater increase in 1RM strength on seated rows does not reach statistical significance.

Figure 2: Changes in body composition after 8 weeks of strength training with (CS) and without (PL) Cordyceps sinensis supplementation (data based on Hsu. 2011).

Similarly, the cordyceps supplement had no measurable beneficial effects on the accrual of lean or the loss of fat mass in the course of the 8-week strength training protocol (cf. figure 2). Although statistically non-significant, the subjects who received the CS supplement did in fact lose some lean mass and gain some fat mass... certainly not what you would have expected from the purchase of a "testosterone boosting adaptogen"!?

Figure 3: Testosterone levels after 8 weeks of strength training with (CS) and without (PL) Cordyceps sinensis supplementation (data based on Hsu. 2011).

A pros pos "testosterone boosting", as the data in figure 3 clearly shows, there was a "boost", but the latter was identical between groups and - as the body composition data in figure 2 shows - the placebo group, whose baseline testosterone levels were 7% lower than those of the subjects in the CS group, took greater advantage from this probably exercise-induced and in view of the diurnal fluctuations of serum testosterone statistically non-significant increase.

Figure 4: Changes in serum levels of BUN, Creatinine, ALT and AST after 8 weeks of strength training with (CS) and without (PL) Cordyceps sinensis supplementation (data based on Hsu. 2011).

It would be unfair though to say that the ingestion of 2.4g of Cordyceps sinensis was totally pointless. After all there was a non-negligable decrease in the purported "liver values" ALT and AST. Now, as a diligent reader of the SuppVersity you are among the few chosen ones who outsmart 99% of the general practitioners and know that the enzymes ALanine Transaminase (ALT) and ASpartate Transaminase (AST) are by no means "liver values", i.e. liver-specific. In fact, their elevation in hard training athletes is completely normal and an indicator of muscular, not hepatic, damage, as both, ALT and ALT, are expressed in skeletal muscle, as well (Petterrson. 2007). This does not change that - once again - beneficial effects that have repeatedly been observed in rodent studies did not translate to humans, but it could explain why Quinc, senior member on the Mind and Muscle Forum and a true believer in the potency of cordyceps maintains:

I can't say I have noticed any 1RM gains, but I have noticed a quicker recovery time between sets and more endurance. (Quinc. 2011)

In view of the beneficial effects on the amino acid transferase enzymes, it may well be that the scientists just measured the wrong parameters. If their subjects had participated in the Tour de France, it could well be that the CS group had survived a few kilometers more, before they had had to be picked up by one of the team vehicles ;-)