Yan X.-F. et al. Effect of Cordyceps sinensis on the oxidative stress in aged people. Phytother Res. 2010;24(9):1358-1365.
Rationale
Accumulation of reactive oxygen species with a concurrent decline in antioxidant enzyme activity is considered one mechanism of cellular aging in the elderly. The authors examined whether prolonged intake of fermented Cordyceps sinensis mycelium (strain Cs-4) could improve antioxidant-defense markers and reduce lipid peroxidation in elderly volunteers.
Methods
Design — randomized double-blind placebo-controlled trial. Population: 40 elderly volunteers, mean age 65. Intervention: daily 3 g/day of Cs-4 mycelial powder in capsules or identical placebo for 12 weeks. Endpoints: plasma superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity and malondialdehyde (MDA) level as a lipid-peroxidation marker; blood drawn at baseline and at course end.
Results
By the end of week 12, the active group showed a statistically significant increase in plasma SOD activity and a trend toward higher GPx activity; MDA levels simultaneously fell, interpreted as reduced lipid peroxidation. Exact p-values and 95% CIs are not given in the available abstract description; specific numerical changes in SOD, GPx and MDA should be checked against the full text. Adverse events are not reported in the annotation.
Conclusions
The authors conclude that prolonged Cs-4 intake in the elderly is accompanied by signs of a systemic antioxidant effect: increased activity of key antioxidant-defense enzymes and a reduced lipid-peroxidation marker. The work complements the earlier Xiao 2004 RCT (VO₂max in the elderly) and extends the Cs-4 effect profile in geriatrics, where direct measurement of antioxidant defense in humans is rare.
Worth noting
The author's abstract is not openly available, so exact p-values, confidence intervals and subgroup distributions are not reproduced here — they should be checked against the full text in Phytotherapy Research (DOI 10.1002/ptr.v24:9). Methodologically the work is limited by a small sample (n=40) and 12-week duration: whether the antioxidant effect persists after discontinuation and whether it is accompanied by clinically meaningful outcomes (functional status, illness frequency, cognitive markers) is unclear. Strain Cs-4 is cultivated Paecilomyces hepiali mycelium, not wild cordyceps, so the data do not automatically transfer to any supplement labeled "Cordyceps." The placebo is not described as "active," which strengthens the design, but an MDA reduction without functional endpoints is not evidence of slowed aging.