Exposure to mild hyperbaric oxygen at a low oxygen concentration (35–40% oxygen) does not result in enhanced levels of oxidative stress in rats and humans. Based on previous findings from experimental animal and human clinical studies, the effects of exposure to mild hyperbaric oxygen at 1266–1317 hPa with 35–40% oxygen are summarized in Table 1. It is noteworthy that these findings were obtained in the first step of exposure to mild hyperbaric oxygen.
•Parkinson’s disease •
It is concluded that exposure to mild hyperbaric oxygen activates oxidative metabolism in the dopaminergic neurons in the substantia nigra and inhibits the reduction in dopaminergic neurons, thereby resulting in the inhibition of Parkinson’s disease.
•Metabolic syndrome •
Exposure to mild hyperbaric oxygen is thus considered to inhibit the growth-related increase in blood glucose levels and decrease the muscle oxidative capacity of rats with metabolic syndrome owing to the improved oxidative metabolism .
Exposure to mild hyperbaric oxygen is effective for elderly people, those with physical disability, as well as injured athletes, since no special movement needs to be performed under mild hyperbaric oxygen conditions. In future, exposure to mild hyperbaric oxygen may be investigated for: prevention and improvement of dementia, improvement of functional imbalances of autonomic (sympathetic and parasympathetic) nerves, e.g., menopausal disorders and emotional instability, maintenance and improvement of immunity, health, and physical fitness, and early recovery from an injury.
Exposure to mild hyperbaric oxygen is effective in decreasing levels of reactive oxygen species overproduced in arthritis .Oxidative stress and C-reactive protein levels are high in rats with arthritis, whereas the levels shifted to those in normal rats by exposure to mild hyperbaric oxygen .Arthritic joints are characterized by hypoxia caused by an increased oxygen demand and decreased blood flow triggered by the increased intraarticular pressure. Therefore, exposure to mild hyperbaric oxygen is effective in reducing reactive oxygen species levels overproduced during arthritis .