Environmental Stress Management at High Altitudes by Adaptogens
Summary of Unpublished Manuscript Presented by
K. K. Srivastava1
Several crude plant and animal preparations, which are generally ill-defined chemically, have been used for ages in many oriental systems of medicine for managing stress and increasing endurance. Such products have been called adaptogens. However, evidence for the efficacy of such medicines, despite their age-old and world-wide use, in well-controlled experiments is lacking. Therefore, such preparations and their effects are considered largely unsubstantiated and unfounded.
An experimental animal model for evaluating adaptogens and their antistress effect was described. In this model, the physiological response monitored under multiple stresses was the capacity of the homeothermic animal (rat) to maintain core body temperature in a hypobaric cold chamber. Any antistress effect of a preparation observed in this model would presumably represent a general antistress effect. A composite Indian herbal preparation (the crude drug powder, a commercial preparation of CIHP available in India called
Geriforte) was tested with this model, and it was found to be a strong antistress adaptogen. The long-term administration of CIHP to rats (6 weeks) at a dose of 1 mg/g body weight increased the duration of time to reach a core temperature of 23°C (73°F) by 72 percent and decreased the recovery time by 46 percent. Results obtained with this experimental animal model suggest that CIHP administration induces significant thermoregulatory tolerance to cold and hypoxia.
In a subsequent placebo-controlled, double-blind trial of CIHP, human male volunteers, who remained at extreme altitudes (4,800 to 6,000 m [15,748 to 19,684 ft]) for a period of 3 or 6 months, were tested for various indices at 3,050 m (10,007 ft) prior to their induction to higher altitudes (4,800 to 6,000 m [15,748 to 19,684 ft]) and again 6 months after their return to the plains after the high-altitude stay. Environmental stresses at the higher altitudes consisted of hypobaric hypoxia (420 to 335 mm Hg), low temperature (-40° to 0°C [-40° to 32°F]), high-velocity winds (0 to 150 km/h), and sunlight, which created intense heat, blinding reflection on the snow, and increased ultraviolet and ionizing radiation. The psychological stresses consisted of isolation, uncertainty of weather conditions, and enhanced physical exertion.
A randomly assigned group of 14 men remained and worked in the high mountains for a period of 3 months, and a second group of 30 men remained for 6 months. Each group was further divided at random into two subgroups. The subgroups were given placebo or CIHP tablets. The volunteers were examined a second time at 3,050 m (10,007 ft) within 7 days of their descent from the high mountains. The third set of data was recorded 6 months after returning to the plains from altitude.
During the human subjects' prolonged stay and work for 3 months in the high mountains (4,800 to 6,000 m), the placebo-administered group lost 3.3 percent of their body weight. The group given CIHP lost 2.67 percent of their body weight. After returning from high altitude and staying 6 months in the plains, subjects gained body weight, which exceeded their initial body weight by 1.65 percent and 4.75 percent in placebo and CIHP groups, respectively. These data show that the administration of adaptogens in a high-altitude environment helped to maintain subjects' body weight and, on returning to the plains, helped further to increase body weight, even though the administration of adaptogen was discontinued after the return from high altitude. However, in subjects who stayed 6 months at high altitude, the loss in body weight could not be arrested by CIHP administration. Gain in body weight during their stay in the plains also did not exceed significantly their initial body weight.
The effect of high altitude on some of the higher cognitive functions of humans indicated that the perception and concentration functions deteriorated after a stay of 3 months in the high mountains. These functions recovered fully on return to lower altitude within 6 months. In those subjects who were given CIHP at high altitude, a deterioration in perception was not observed. Deterioration in concentration was observed in subjects give CIHP (p < 0.05).
CIHP was able to restore the deterioration in perception and concentration functions in subjects who stayed in the high mountains for 6 months, but the vigilance function deteriorated to the same extent both in subjects given placebo and those given CIHP. Upon return to the plains, all of the higher functions of the brain described above recovered fully in the placebo group, as well as in the adaptogen group.
The oxygen consumption during rest and on maximal exercise before and after exposure to extreme altitudes in the plains had been studied. The maximal exercise oxygen consumption did not show any significant difference between placebo- and CIHP-administered volunteers at the end of 3 and 6 months of stay at extreme high altitudes. However, on return to the plains the oxygen consumption on maximal exercise was significantly elevated in CIHP-given volunteers as compared with the placebo group, suggesting an increased exercise tolerance and endurance capacity. The increase in creatine phosphokinase in circulation on prolonged stay at extreme high altitudes (125 percent) was found to be restricted (30 percent only) in CIHP-given volunteers, suggesting improved skeletal muscle and/or neural tissue oxygenation.
Evidence of adequate heart oxygenation in adaptogen-administered subjects in the high mountains was obtained from the electrocardiographic observations of subjects. In placebo-administered subjects 42.8 percent (three out of seven) showed a right axis shift of 10° to 30°. The CIHP-administered subjects did not show any electrocardiographic abnormalities. After 6 months of stay at high altitudes, CIHP administration had reduced the magnitude of axis shift and T-wave changes. The reduced incidence and magnitude of right axis shift in CIHP-administered subjects is suggestive of decreased right ventricular load. This might have occurred due to the decrease in high altitude-induced pulmonary hypertension in adaptogen-administered men.
The observations on human subjects exposed to a high-altitude environment of 4,800 to 6,000 m (15,748 to 19,684 ft) for a prolonged stay of 3 or 6 months suggest that remaining at these altitudes was accompanied by a loss in body weight, deterioration in mental and physical performance, cellular oxygenation, and cardiac stress. Administering the adaptogen CIHP arrested either partially or fully such changes when the stay was restricted to 3 months. CIHP was not able to reverse the high altitude-induced deterioration in most of the functions when the stay was prolonged to 6 months. However, the changes were fully reversed upon returning to the plains within a period of six months. The changes in o2max showed improvement in the adaptogen-administered group as compared with the placebo-administered group upon return to the plains.
In conclusion, the animal and human studies described herein suggest that CIHP administration is effective in maintaining and assisting thermoregulation in a challenging cold and hypoxic environment. Furthermore, CIHP can arrest the altitude-induced physiological deterioration to some extent in humans. These studies have proven, to a reasonable extent, that CIHP has antistress and
adaptogenic action. CIHP is representative of a large number of formulations described as rasayan in ayurveda and several preparations of other oriental systems of medicine. These drugs or food supplements have the potential to act as rejuvenators and vitalizers for the strengthening of healthy humans. A large trial of CIHP, with a view to reducing cold- and hypoxia-induced injuries and diseases in extreme cold and high-altitude areas beyond 5,000 m (16,404 ft), is indicated.
Contributions and support from the following coinvestigators are acknowledged with pleasure: Vimla Asnani, S. K. Bhardwaj, H. M. Divekar, A. K. Gupta, S. K. Grover, R. K. Gautam, Ratan Kumar, M. L. Pahwa, M. R. Panwar, Uma Ramachandran, Om Veer Singh, T. N. Upadhyay, and P. Bandyopadhyay. The author is also deeply indebted to soldiers of the Indian Army (20 jats and 13 grenadiers) and their officers who served as volunteers, to the medical specialists of the Indian Army Hospitals for the clinical investigations, and to Uma Sanduja for secretarial assistance.