Effects of Magnesium Hydride as a Reductive Bath Additive on the Skin

We have proposed so far that natural hot spring source waters fresh out of wellheads have essentially a reductive characteristic, and that the use of magnesium hydride (MgH2 ; hydrogen generating agent) is effective in preparing bathwater having a reductive characteristic equivalent to that of hot spring source waters. Moreover, in a series of our previous research papers, we have reported that, since hydrogen makes bathwater reductive, the elasticity of the human skin can be improved through habitual bathing in water hydrogenated by dissolution of electrolytically produced hydrogen therein (electrolyzed reductive water). In the present study, magnesium hydride was added to non-circulated hot spring source water in bathtubs of Ashino Onsen (alkaline simple spring, Tochigi Prefecture) so as to prepare hydrogenated hot spring water having a hydrogen concentration exceeding 50 ppb (μg/kg), at which improvements in skin elasticity through habitual bathing in electrolyzed reductive water had been confirmed in our previous examinations. For a period of one midwinter month starting from the middle of January 2013, experiments of habitual bathing by volunteer subjects were carried out to measure the elasticity coefficients of the skin (flexural side of forearm) of each subject. With the purpose of comparison, the subjects were divided into three groups ; habitual bathing in hydrogenated Ashino hot spring water (prepared by addition of magnesium hydride), habitual bathing in intact Ashino hot spring water without the addition of magnesium hydride, and habitual bathing in home-use bathwater (including showering). The result data of the elasticity coefficients of the skin in the bathing experiments showed that there was a tendency to decrease in the group of subjects bathing in home-use bathwater, and no change was found in the group of subjects bathing in intact Ashino hot spring water, whereas a statistically significant improvement effect was observed in the group of subjects bathing in hydrogenated Ashino hot spring water. Further, skin elasticity data measured immediately before the start of the present bathing experiments were in good agreement with the hitherto reported literature data showing a tendency to decrease with age in skin elasticity. It is, therefore, suggested that habitual bathing in hot spring water hydrogenated by addition of magnesium hydride can contribute to providing an anti-aging effect on the skin. Besides, in an additional experiment of bathing in hot tap water hydrogenated by addition of magnesium hydride, an effective increase in deep body temperature (tympanic temperature) was confirmedly observed as in the case of artificial CO2 hot spring water (CO2 concentration : 1,000 mg/dm).