Cordyceps is a Tibetan mushroom used in traditional Chinese medicine (TCM) for “lung protection” and “reproductive invigoration” as well as to balance the “Qi” – the fundamental “energy of life.” In “Western” terminology, cordyceps is also used as a traditional remedy for ailments of the immune system, endocrine system, cardiovascular system, respiratory system, renal system, and hepatic system. Of the available clinical (human) data published in English, there is evidence for a beneficial effect of cordyceps in relieving asthma, increasing lung function, and boosting libido.
Although the pharmacologically active components of cordyceps remain unknown, at least two chemical constituents; cordycepin (deoxyadenosine) and cordycepic acid (mannitol) have been identified and suggested as being the active compounds in improving lung function and increasing energy levels and sex drive.
Although a number of studies have been conducted on cordyceps in China, relatively little information is available from U.S.-based scientists. Animal studies have shown cordyceps feeding to increase the ratio of adenosine triphosphate (ATP) to inorganic phosphate (Pi) in the liver by 45-55% - an effect that may be viewed as beneficial in terms of energy state and potential for performance enhancement. Furthermore, mice fed cordyceps and subjected to an extreme “low oxygen” environment, were able to utilize oxygen more efficiently (30-50% increase), better tolerate acidosis (lactic acid accumulation) and hypoxia (lack of oxygen), and live 2-3 times longer than a control group.
A number of Chinese clinical studies, primarily in elderly patients with fatigue, showed that cordyceps-treated patients reported significant improvements in their level of fatigue, ability to tolerate cold temperatures, and benefits on measures of memory, cognitive capacity, and sex drive. Patients with respiratory diseases also reported feeling physically stronger. Overall, the efficacy rate for cordyceps in alleviating fatigue in elderly subjects was 80-90%.
A great deal of the scientific evidence for the physiological effects of cordyceps mushroom comes from the wide variety of animal studies available in translations from the Chinese language journals in which they are published. In these studies, cordyceps is shown effective for controlling blood levels of insulin, glucose, and corticosterone, as well as increasing numbers and activity of many immune cell fractions, including T-helper cells and natural killer cells (Bao et al. 1988; Kuo et al. 1996; Zhu et al. 2001). Animal studies have also shown cordyceps feeding to increase the ratio of adenosine triphosphate (ATP) to inorganic phosphate (Pi) in the liver by about 50% - resulting in an ability to utilize oxygen more efficiently (30-50% increase), better tolerate acidosis and hypoxia (lack of oxygen) and live 2-3 times longer than a control group exposed to a low oxygen environment (Zhu et al. 2001).
Of the few clinical studies available, cordyceps-treated subjects show significant improvements in their level of fatigue (Cooper et al. 1999), memory and cognitive capacity (Zhu et al. 1998a), sex drive (Zhu et al. 1998b), oxygen uptake (Cooper et al. 1999; Talbott et al. 2002), and endurance exercise performance (Nicodemus et al. 2001). One human study (Zhu et al. 1998b) suggests that the increased libido reported in elderly subjects may be due to an increase in DHEA levels from low back to normal ranges.
In addition to its effects on energy levels – possibly due to the adenosine content of cordyceps – the mushroom extract can also induce sex steroid-like effects (in mice and in isolated cell cultures) – which may account for the increased libido reported by elderly subjects in several studies.
Of note, are three recent studies investigating the endurance effects of a cordyceps-only (Cordymax from Pharmanex) and a cordyceps + rhodiola supplement (Optygen from First Endurance), which all showed no beneficial effects on endurance performance in trained athletes:
Cordymax – International Journal of Sports Nutrition and Exercise Metabolism (April 2004) – researchers at Brigham Young University in Utah found no beneficial effects in cyclists supplemented with the highest dose of Cordymax (3g/day for 5 weeks) on measures of VO2peak, ventilatory threshold, or time trial performance. These results indicate no effect of Cordymax on aerobic capacity or endurance exercise performance in trained male cyclists.
Optygen – Journal of Strength and Conditioning (May 2005) – no effects on muscle tissue oxygen saturation, VO2max, ventilatory threshold, or time to exhaustion in subjects supplemented with Optygen and given 2 exercise stress tests to fatigue on a cycle ergometer.
Optygen – Medicine and Science in Sports and Exercise (March 2004) – Researchers at the Cooper Institute Center for Human Performance and Nutrition Research found no beneficial effects of Optygen supplementation (6 capsules per day for 4 days of “loading” and 3 capsules per day for 11 days of “maintenance”) in competitive trained cyclists. No effects were seen for measures of peak VO2, time to exhaustion on a cycling test, peak power output, peak heart rate, lactic acid levels, ventilatory theshold, respiratory compensation point, or gross oxygen efficiency.
Suggested dosage ranges for cordyceps vary widely due to differences in potency of cordyceps extracts. Lower-potency extracts may need to be supplemented at 2-4 grams per day, while higher-potency extracts (e.g. standardized to 7% cordycepic acid) are effective at lower levels (1,000mg/day) for increased energy levels, reduced fatigue and an enhanced ability to use oxygen.
Dietary supplementation with Cordyceps is not associated with any significant side effects, although the theoretical possibility exists for adenosine-containing supplements to induce a slight “blood-thinning” effect. Typical doses used in clinical studies have ranged from 2-6 grams per day (of the lower-strength extracts) for benefits associated with increased energy levels, reduced fatigue and an enhanced ability to use oxygen.
In addition to being used by TCM practitioners as a generally invigorating energy tonic, cordyceps is most often found in modern dietary supplements as a component of products intended to enhance endurance, energy, or athletic performance. Typical claims made for cordyceps-containing products include: