“Hot springs beneficial to the skin” have different water qualities

Hot springs vary. In Japan, there are 10 types of hot springs which contain different ingredients and have different effects. There are countless “hot springs good for beautiful skin” with different water qualities and benefits across the nation. Hydrogen carbonate (sodium bicarbonate) and sulfur springs contain sodium bicarbonate and sulfur respectively, which soften the dead cells and make the skin smooth. Chloride springs are known to penetrate and effectively moisturize the skin by soaking skin surface proteins and lipids in chloride. Recently, one ingredient was scientifically proved, though partially, to have “benefits to the skin”: alum contained in Myoban Onsen in Beppu, Oita Prefecture.

Alum “hot spring deposits” of Myoban Onsen have medical effects

Myoban Onsen is a hot spring resort traced back to the period of the warring states. Its water is a strong acid and disinfectant. It is effective for neuralgia and skin diseases and has long been known to be beneficial to the skin. In the middle of the Edo Period, hot spring gas was condensed and crystalized to have alum “hot spring deposits.” They are being produced in the same way even today and are sold as quasi-drug bath additives.

Alum is an ingredient used to remove the harshness of vegetables from old times and also as deodorant and antiperspirant. How does alum act on the skin? Why is Myoban Onsen “beneficial to the skin”? The answers to these questions have some connection with the TRP channel family, or the cell censors of temperature and stimuli.

What is “Alum K,” which checks production of inflammatory substances in the skin?

Skin inflammation occurs due to an immune response to protect the skin when it is exposed to external stimuli, including ultraviolet rays and temperature change. Such inflammation is not severe and relatively “invisible.” If not healed quickly, it causes several troubles such as rough and dry skin, large pores and uneven texture, and finally results in aging skin with loss of firmness and wrinkles.

It was discovered that TRPM4, when activated, stops “invisible inflammation” from occurring. According to a Mandom research study, TRPM4 controls production of inflammatory substances in the cells, thereby improving water content and firmness, treating large pores, etc., This cell sensor is activated by “Alum K.”

Warming the body is essential to activate TRPM4

When you soak yourself in a hot spring, alum (Alum K) dissolved in the water activates TRPM4, checking production of inflammatory substances and healing the skin. The inflammatory substances are produced by stimuli to the skin and are “causes” of skin troubles and aging. Myoban Onsen is beneficial to the skin partly because alum prevents the “causes” from being produced. TRPM4 is activated by not only a hot spring but also hot tap water. It is difficult to go to a hot spring in the coronavirus pandemic. Take a warm bath at home and keep the body, mind and skin warm and beautiful.