Randomized double-blind placebo-controlled clinical trial and assessment of fermentation product of Cordyceps sinensis (Cs-4) in enhancing aerobic capacity and respiratory function of the healthy elderly volunteers
Objective: Cordyceps sinensis (CS) is a popular natural Chinese herbal medicine for invigoration, health preservation and reducing fatigue. Its natural substance has been prepared as a fermentation product of a specific strain of Cordyceps sinensis (Cs-4). Our objective was to assess the effect of Cs-4 on the exercise capacity of the healthy elderly people in a randomized, double-blind, placebo-controlled trial.Methods: Thirty-seven healthy, elderly Chinese subjects were randomly assigned to receive either Cs-4 (3 g/ day) or identical placebo capsules. Their exercise performance was tested before and after 6 weeks of treatment with a symptom-limited, incremental work rate protocol on a cycle ergometer. Maximum oxygen uptake (VO2max) was measured using a metabolic chart. Anaerobic thresholds (VO2θ) were identified by two observers using plots of both VCO2 vs VO2 and VE/VO2 vs time.Results: After taking Cs-4 for 6 weeks, VO2max (1.88 ±0.13 to 2.00 ±0.14 L/min;P = 0.050) and VO2θ (1.15 ±0.07 to 1.30 ±0.09 L/min;P = 0.012) were significantly increased, whereas after placebo application they were unchanged.Conclusion: These findings support the belief held in China that Cs-4 could improve oxygen uptake or aerobic capacity and ventilation function and resistance to fatigue of elderly people in exercise.