Method for improving occupational stress

Abstract

To provide a method for improving occupational stress by bathing with bicarbonate bath additives.SOLUTION: A method for improving occupational stress by bathing with bicarbonate bath additives, in which the bicarbonate bath additives contains a bicarbonate salt consisting of sodium bicarbonate or potassium bicarbonate and an organic acid as a composition and the mixing ratio of the composition is set so that the bath water in which the bicarbonate bath additives are dissolved is approximately neutral, improves occupational stress through physiological functions based on vascular dilation caused by transdermal absorption of bicarbonate ions dissolved in the bath water.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a method for improving occupational stress, and more particularly to a method for improving occupational stress by taking a bath using a bicarbonate bath additive. [Background technology]

[0002] In recent years, occupational stress has become a social issue. Occupational stress is stress that occurs during work, and according to the definition of the World Health Organization (WHO), it is "the reaction that people may have when they are faced with work that does not match their knowledge and abilities due to the demands and pressures of their job." Specifically, it is stress that workers experience due to interpersonal relationships, degree of control over their work, workload, overtime work, future prospects of the job, suitability for the job, work systems such as shift work and business trips, and the workplace environment.

[0003] As a technique for checking such occupational stress, for example, Patent Document 1 below discloses a system for calculating an estimated mild illness score using a simple occupational stress questionnaire created by the Ministry of Health, Labor and Welfare. In addition, Patent Document 2 below discloses a method for evaluating and improving mental health risks that utilizes risk values ​​of mental and physical stress reactions in occupational stress. In addition, Patent Document 3 below discloses a stress check system that performs an occupational stress check, and Patent Document 4 below discloses an analysis device for an occupational stress survey. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-157474 A [Patent Document 2] Patent Publication No. 2022-176775 [Patent Document 3] JP 2019-046003 A [Patent Document 4] JP 2018-136624 A [Patent Document 5] Patent No. 5877778 [Non-patent literature]

[0005] [Non-Patent Document 1] Nobuhiro Maruyama and Shigeji Koboshi, "No. 29 Development of bicarbonate ion-citric acid bath additives and measures to prevent illness", Journal of the Japanese Society of Balneology, Climatology, and Physical Medicine, Vol. 78, No. 1 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, various techniques for checking occupational stress have been disclosed, but no techniques for improving occupational stress have been disclosed. In order to improve occupational stress, it is necessary to improve the workplace environment that causes stress or to release stress, but it is not easy for an individual to improve the workplace environment. On the other hand, actions that an individual can take include, for example, light exercise, taking a bath, and sleeping soundly, and these actions can release stress. Among these, bathing and sleeping are daily actions, so it would be convenient if bathing and sleeping could improve occupational stress.

[0007] Now, regarding sleep, during sleep, the core body temperature drops to allow the organs, muscles, and brain to rest. This core body temperature is regulated by heat production by the muscles and internal organs and heat dissipation from the hands and feet. Before falling asleep, the hands and feet become warm and heat dissipation from the hands and feet increases, causing the core body temperature to drop, but since the core body temperature is under the influence of homeostasis, it does not drop easily. On the other hand, when the core body temperature rises temporarily, it has the tendency to drop by the same amount. Therefore, if the core body temperature can be raised by taking a bath, it will drop significantly a while after the bath. As a result, the core body temperature drops by a large amount, turning on the switch for falling asleep (called the body temperature switch), allowing you to fall asleep smoothly and improving the quality of your sleep.

[0008] Because bathing and sleep are so closely related, if bathing can improve the quality of sleep, it can effectively alleviate occupational stress. However, bathing in normal hot water or bathing with common bath additives cannot improve the quality of sleep by greatly lowering the core body temperature, cannot relax the mind and body by making the parasympathetic nervous system dominant, and cannot increase blood flow to promote the supply of nutrients and the removal of fatigue substances, so it cannot effectively alleviate occupational stress.

[0009] The present invention has been made in consideration of the above problems, and its main object is to provide a method for improving occupational stress by bathing with a bicarbonate bath additive. [Means for solving the problem]

[0010] One aspect of the present invention is a method for improving occupational stress by bathing with a bicarbonate bath additive, the bicarbonate bath additive comprising a composition comprising a bicarbonate salt consisting of sodium bicarbonate or potassium bicarbonate, and an organic acid, the mixing ratio of the composition being set so that the bath water in which the bicarbonate bath additive is dissolved is approximately neutral, and the occupational stress is improved by a physiological function based on vascular dilation caused by transdermal absorption of the bicarbonate ions dissolved in the bath water. Effect of the Invention

[0011] According to the present invention, occupational stress can be improved by taking a bath using a bicarbonate bath additive.

[0012] The reason is that bicarbonate bath additives contain bicarbonate salts consisting of sodium bicarbonate or potassium bicarbonate and organic acids as a composition, and the mixing ratio of the composition is set so that the bath water in which the bicarbonate bath additives are dissolved is approximately neutral, and by promoting the percutaneous absorption of bicarbonate ions dissolved in the bath water and dilating blood vessels, it is possible to increase blood flow and temporarily raise the core body temperature, increase the extent of the drop in core body temperature, and improve the quality of sleep, and also to relax the mind and body by making the parasympathetic nerves dominant, and to promote the supply of nutrients and the removal of fatigue substances by increasing blood flow, and these physiological functions can improve occupational stress. In addition, by taking a bath under appropriate bathing conditions (bath temperature, bicarbonate ion concentration, and bathing time), it is possible to further promote the percutaneous absorption of bicarbonate ions and dilate blood vessels, thereby enhancing the above physiological functions and more effectively improving occupational stress. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram illustrating the mechanism of vasodilation caused by transdermal absorption of bicarbonate ions. [Diagram 2] FIG. 13 is a diagram showing the correlation between bathing time and blood flow rate in one embodiment of the present invention. [Diagram 3] FIG. 13 is a diagram showing the correlation between bathing temperature and blood flow rate in one embodiment of the present invention. [Figure 4] FIG. 1 is a graph showing the correlation between bicarbonate ion concentration and blood flow rate according to one embodiment of the present invention. [Diagram 5] FIG. 13 is a diagram showing the correlation between bathing time and deep body temperature in one embodiment of the present invention. [Figure 6] FIG. 13 is a diagram showing the correlation between bathing duration and core body temperature in one embodiment of the present invention. [Figure 7] FIG. 1 shows a simplified version of the 23-item Occupational Stress Questionnaire. [Figure 8] FIG. 1 shows the effect of a bicarbonate bath on improving occupational stress. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] As shown in the Background Art, bathing is an effective method for improving occupational stress, but since bathing in normal hot water or bathing with general bath additives does not effectively improve occupational stress, bath additives with high bathing effects are in demand. Bath additives made by molding a mixture containing bicarbonate (sodium bicarbonate or potassium bicarbonate) and an organic acid by tableting or the like are actively used as such bath additives. When added to hot water, the bicarbonate is neutralized by the organic acid to generate carbon dioxide gas, which gives consumers a comfortable feeling when used.

[0015] However, when bicarbonate and organic acid are combined and made into tablets, a vigorous neutralization reaction occurs during dissolution in hot water, generating large carbon dioxide bubbles that merge and grow larger, causing the carbon dioxide to rise rapidly into the air due to their buoyancy. As a result, less carbon dioxide dissolves in the water, and the bathing effect of carbon dioxide is not achieved.

[0016] In response to this problem, the inventors of the present application conducted a detailed study of the effects of natural carbonated springs, and found that the weak acidity of natural carbonated springs is merely due to the pH value, not due to any acidic components, but rather due to trace amounts of mineral ions dissolved by high pressure deep underground, resulting in a weak acidity with no potency (acidity that is not an excess of organic acids) caused by the dissociation of the slightest amount of negative ions, and that the weak acidity is such that carbon dioxide is neutralized and the bath becomes neutral simply by coming into contact with bodily fluids that have been adhering to the skin or hair.They then discovered that it is completely pointless for commercially available bath additives to only imitate the pH value of natural carbonated springs by adding an excess of organic acids, making the bath weakly acidic and making it easier for the carbon dioxide to effervescent.

[0017] Therefore, the inventors of the present application have proposed a tablet manufacturing method and tablet production method in which an organic acid is used as a compound that neutralizes the compound used as a carbon dioxide gas generating source, i.e., bicarbonate (sodium bicarbonate, potassium bicarbonate), and in the presence of polyethylene glycol, the tablet is compressed to produce a tablet of a certain level of hardness and a certain size (Patent Document 5).

[0018] Inside the tablet produced by the method of Patent Document 5, a vigorous and efficient neutralization reaction occurs, and by continuously releasing the smallest possible carbon dioxide bubbles for a certain period of time, most of the generated carbon dioxide can be dissolved in water without escaping into the air. In addition, by designing the pH to be neutral immediately after dissolution, the bicarbonate ions in the water are highly concentrated, and due to the pH of the aqueous solution, carbon dioxide that comes into contact with the skin easily becomes bicarbonate ions, and when combined with the naturally existing bicarbonate ions, the concentration becomes high, allowing the absorption of bicarbonate ions into blood vessels from the skin to be maximized, and the blood vessels can be dilated by the percutaneous absorption of bicarbonate ions.

[0019] The effect of bicarbonate ions will now be explained. Generally, carbon dioxide dissolved in water exists as dissolved inorganic carbon, but this dissolved inorganic carbon exists in three forms due to bicarbonate equilibrium, and it is said that the form changes depending on the pH of the solution. It is known that the abundance ratio of the three types of dissolved inorganic carbon depending on the pH is such that in the region where the pH of the solution is weakly acidic or lower, the proportion of bicarbonate ions is low and the proportion of carbonic acid is high, in the neutral to weakly alkaline region, the proportion of bicarbonate ions is highest, and in the alkaline region, the bicarbonate ions are low and the carbonate ions are high, symmetrically.

[0020] In addition, carbon dioxide is said to migrate from the skin surface to the capillaries via an accessory organ pathway that passes through the pores and sweat glands of the skin. Since the pH range of blood coincides with the pH range in which bicarbonate ions are present at their highest concentration, the inventors of the present application focused on the possibility that much of the carbon dioxide that migrates from the skin into the blood may exert physiological activity as bicarbonate ions and have beneficial effects on the living body, and investigated the effects of bicarbonate ions on the living body (see non-patent document 1).

[0021] As a result, in an in vivo test, blood flow in mice was significantly increased compared to the control group, and there was a tendency for an increase in the amount of bicarbonate ions in the blood and in NO production via phosphorylation of endothelial nitric oxide synthase in peripheral blood. Furthermore, in an in vitro test using human umbilical artery endothelial cells, promotion of phosphorylation of endothelial nitric oxide synthase and an increase in NO production were detected in the presence of neutral bicarbonate ion water, and the reactive oxygen species scavenging activity of neutral bicarbonate ion water was significantly higher than that of the control group.

[0022] From these findings, it has become clear that bicarbonate ions, when absorbed percutaneously, act directly on the vascular endothelium to phosphorylate endothelial nitric oxide synthase, thereby dilating blood vessels by increasing NO production. By dilating blood vessels, blood flow is increased, temporarily raising core body temperature, and the degree of decrease in core body temperature is increased, thereby improving sleep quality. It can also put the parasympathetic nervous system into a dominant state, relaxing the mind and body, and increasing blood flow to promote the replenishment of nutrients and the removal of fatigue-causing substances. Therefore, it has been found that by using a bath additive such as that described in Patent Document 5 (referred to as a neutral bicarbonate bath additive), occupational stress can be effectively improved by the physiological function based on the dilation of blood vessels caused by the percutaneous absorption of bicarbonate ions.

[0023] The inventors of the present application also investigated the correlation between the time spent bathing in water containing dissolved neutral bicarbonate bath agent and blood flow rate, the correlation between the temperature of the water containing dissolved neutral bicarbonate bath agent and blood flow rate, the correlation between the bicarbonate ion concentration in the water and blood flow rate, the correlation between the time spent bathing in water containing dissolved neutral bicarbonate bath agent and deep body temperature, and the correlation between the duration of continuous bathing using neutral bicarbonate bath agent and deep body temperature, and found that the blood flow rate and deep body temperature changed significantly depending on the temperature of the water, the bicarbonate ion concentration, and the bathing time. From these results, the inventors found that by bathing using neutral bicarbonate bath agent under appropriate conditions, it is possible to further promote the percutaneous absorption of bicarbonate ions and expand blood vessels, thereby enhancing the above physiological functions and more effectively alleviating occupational stress. EXAMPLES

[0024] In order to explain the above-mentioned embodiment of the present invention in more detail, a method for improving occupational stress according to an embodiment of the present invention will be described with reference to Figs. 1 to 8. Fig. 1 is a schematic diagram for explaining the mechanism of vasodilation caused by percutaneous absorption of bicarbonate ions, Fig. 2 is a diagram showing the correlation between bathing time and blood flow in this embodiment, Fig. 3 is a diagram showing the correlation between bathing temperature and blood flow in this embodiment, and Fig. 4 is a diagram showing the correlation between bicarbonate ion concentration and blood flow in this embodiment. Fig. 5 is a diagram showing the correlation between bathing time and deep body temperature in this embodiment, and Fig. 6 is a diagram showing the correlation between the duration of bathing and deep body temperature in this embodiment. Fig. 7 is a diagram showing 23 items of a simplified version of the occupational stress simple questionnaire, and Fig. 8 is a diagram showing the effect of improving occupational stress by bicarbonate bathing.

[0025] First, the mechanism by which blood vessels expand due to bicarbonate ions will be explained. Figure 1 shows a schematic diagram of the structure of human blood vessels, with dermis / subcutaneous adipose tissue 2 inside epidermis 1, and blood vessels 5 inside dermis / subcutaneous adipose tissue 2. Blood vessels 5 are composed of vascular walls 6 with smooth muscles 7 and vascular endothelial cells 8 inside the vascular walls, and the inside of the vascular endothelial cells 8 is the inside of blood vessels 9. When a person bathes in hot water containing dissolved bicarbonate ions, as shown in Figure 1, bicarbonate ions penetrate into blood vessels 9 through sweat pores 4 and the like, phosphorylating endothelial nitric oxide synthase (eNOS) present in vascular endothelial cells 8 (P-eNOS), which acts on L-arginine (L-Al) to generate nitric oxide (NO). The generated NO is converted to cyclic guainosine monophosphate (cGMP) via guanosine triphosphate (GTP) by guanylate cyclase enzyme (sGC). The cGMP then relaxes smooth muscle 7 in the vascular wall 6, resulting in dilation of blood vessels 5 and increased blood flow.

[0026] Therefore, by taking a bath using a neutral bicarbonate bath additive that generates bicarbonate ions in the water and makes the water approximately neutral (called a bicarbonate bath), it is possible to increase the percutaneous absorption of bicarbonate ions, phosphorylate endothelial nitric oxide synthase through its direct action on the vascular endothelium, and dilate the blood vessels by increasing NO production. The dilation of blood vessels increases blood flow and temporarily raises the core body temperature, and the degree of decrease in core body temperature can be increased to improve the quality of sleep. In addition, the dilation of blood vessels can put the parasympathetic nervous system into a dominant state, relaxing the body and mind, and the dilation of blood vessels can increase blood flow, promoting the replenishment of nutrients and the removal of fatigue-causing substances. These physiological functions can effectively improve occupational stress.

[0027] In order to maximize the effects of bathing, such as expanding blood vessels and raising core body temperature through the transdermal absorption of bicarbonate ions, it is important to optimize the bathing conditions related to the transdermal absorption of bicarbonate ions (such as the time spent bathing in water with dissolved bath additives, the temperature of the water in which the bath additives are dissolved, and the concentration of bicarbonate ions in the water).

[0028] Therefore, we investigated bathing conditions to maximize the bathing effect. As mentioned above, when bicarbonate ions are absorbed through the skin, nitric oxide (NO) is generated in blood vessels, which expand the blood vessels and accelerate the blood flow. Therefore, we investigated the optimal bathing time, bathing temperature, and bicarbonate ion concentration by measuring the blood flow rate of the subjects while bathing. This blood flow rate was measured using a non-contact laser Doppler blood flow meter (ALF21N manufactured by Advance Co., Ltd.) by converting the reflected light from the tissue when a laser beam was irradiated onto the biological tissue into an electrical signal and processing it. The measurement was performed at the dorsal side of the hand, which corresponds to the so-called "Hegu" point, and the measurement was performed by attaching a measurement glove to the skin. The unit of blood flow is mL / min / 100g-tissue, but here it is expressed as a multiple of the value before bathing, and the average value of the data obtained by the subjects for 5 days was used.

[0029] First, 210 L of hot water was poured into the bathtub and the bathing temperature was adjusted to 39°C, and neutral bicarbonate bath additives, such as those in Patent Document 5, which dissolve the bath additives in the bathwater to make it approximately neutral, were added to adjust the bicarbonate ion concentration to 2 mmol / L, and the change in blood flow over time was measured when 10 subjects (healthy women aged 20 to 60 years) bathed in the bathtub. For comparison, the change in blood flow over time was also measured when 10 subjects bathed in normal hot water at 39°C. The results are shown in Table 1 and Figure 2.

[0030] [Table 1]

[0031] Fig. 2 shows the correlation between bathing time and blood flow. As shown by the dashed line in Fig. 2, when bathing in normal hot water, body temperature rises and blood flow temporarily increases by about two times due to the action of the autonomic nerves, but the increase in blood flow stops after about 10 minutes, and thereafter, even if the bathing time is extended, blood flow hardly changes. On the other hand, as shown by the solid line in Fig. 2, when bathing in hot water in which the neutral bicarbonate bath agent of this embodiment is added and the bicarbonate ion concentration is adjusted to 2 mmol / L, bicarbonate ions are absorbed transdermally over time, generating nitric oxide in the blood vessels, and cyclic guainosine phosphate generated from nitric oxide relaxes the smooth muscles and expands the blood vessels. As a result, after 10 minutes, the blood flow rate increased to about 5 times that before bathing (considering that the blood flow rate increases about twice when bathing in normal hot water, the increase in blood flow rate due to the transdermal absorption of bicarbonate ions is essentially about 4 times), and after 20 minutes, the blood flow rate increased to about 6 times that before bathing (similarly, considering that the blood flow rate increases about 2 times when bathing in normal hot water, the increase in blood flow rate due to the transdermal absorption of bicarbonate ions is essentially about 5 times), and the blood flow gradually increased thereafter as the bathing time increased. From the results in Figure 2, the blood flow rate was clearly increased when bathing in hot water with dissolved bicarbonate ions compared to when bathing in normal hot water, and considering the significant difference in blood flow rate when bathing in normal hot water, it can be said that the optimal bathing condition is a bathing time of 10 minutes or more, preferably 20 minutes or more.

[0032] Next, 210 L of hot water was poured into the bathtub to change the bathing temperature, and the neutral bicarbonate bath additive of this example was added to adjust the bicarbonate ion concentration to 2 mmol / L. The blood flow rate was measured when 10 subjects (healthy women aged 20 to 60 years) bathed for 20 minutes. For comparison, the blood flow rate was also measured when 10 subjects bathed for 20 minutes in normal hot water with different temperatures. The results are shown in Table 2 and Figure 3.

[0033] [Table 2]

[0034] FIG. 3 is a diagram showing the correlation between bathing temperature and blood flow rate. As shown by the dashed line in FIG. 3, when bathing in normal hot water, body temperature rises with an increase in bathing temperature, and blood flow rate gradually increases due to the action of the autonomic nerves, but the increase in blood flow rate was about 2.4 times or less. On the other hand, as shown by the solid line in FIG. 3, when bathing in hot water in which the neutral bicarbonate bath agent of this embodiment is added and the bicarbonate ion concentration is adjusted to 2 mmol / L, the activity of enzymes (endothelial nitric oxide synthase, guanylate cyclase enzyme, etc.) increases with an increase in bathing temperature, the production of nitric oxide and cyclic guainosine phosphate increases, the relaxation effect of smooth muscles is strengthened, and blood vessels greatly expand. As a result, at 29°C, the blood flow rate is about 3.1 times that before bathing, at 32°C, the blood flow rate is about 5 times that before bathing, and at 40°C, the blood flow rate is about 6.1 times that before bathing, and thereafter, although the change in blood flow rate becomes more gradual, at 43°C, the blood flow rate is about 6.2 times that before bathing. The results in Figure 3 show that when bathing in water with dissolved bicarbonate ions, blood flow is clearly increased compared to bathing in regular water. Considering the significant difference in blood flow compared to bathing in regular water, it can be said that the optimal bathing conditions are a bathing temperature of 29°C to 43°C, preferably 32°C to 40°C.

[0035] Next, 210 L of hot water was poured into the bathtub to adjust the bathing temperature to 39°C, and the neutral bicarbonate bath additive of this example was poured into the bath to change the bicarbonate ion concentration. The blood flow rate was measured when 10 subjects (healthy women aged 20 to 60 years) bathed for 20 minutes. The results are shown in Table 3 and Figure 4. The reason why the blood flow rate at a bicarbonate ion concentration of 0 mmol / L is twice that before bathing is because, as shown in Table 1, the increase in blood flow rate when bathing for 20 minutes in normal hot water at 39°C is twice that before bathing. In addition, in Figure 4, the bicarbonate ion concentration range is changed on the left and right sides of the graph to make it easier to understand the change in blood flow rate under conditions of low bicarbonate ion concentration (1 mmol / L or less).

[0036] [Table 3]

[0037] FIG. 4 is a diagram showing the correlation between bicarbonate ion concentration and blood flow rate. As shown by the solid line in FIG. 4, when taking a bath in hot water in which the neutral bicarbonate bath agent of this embodiment is added and the bicarbonate ion concentration is changed, sufficient nitric oxide is generated even with a small amount of bicarbonate ion absorbed percutaneously, and cyclic guainosine phosphate generated from nitric oxide relaxes smooth muscles and expands blood vessels. As a result, the blood flow rate increases rapidly to about 4.8 times before bathing at 0.1 mmol / L and about 5.3 times before bathing at 0.2 mmol / L, and then increases gradually to about 6.2 times before bathing at 5 mmol / L and about 6.4 times before bathing at 10 mmol / L. From the results in FIG. 4, it can be said that the optimal bathing conditions for bicarbonate ion concentration are 0.1 mmol / L to 10 mmol / L, where blood flow rate increases significantly, and preferably 0.2 mmol / L to 5 mmol / L.

[0038] Since it is believed that the increase in blood flow due to the transdermal absorption of bicarbonate ions will raise the core body temperature, the correlation between bathing time and core body temperature was investigated. To measure the core body temperature, a core thermometer (CORE manufactured by GreenTEG) was used, and the heat flux (amount of heat energy flowing through a unit area per unit time) was measured with a highly sensitive sensor, and the internal body temperature (core body temperature) was calculated from the temperature on the skin surface by processing it with an algorithm. The measurement was performed on the wrist, using a 3cm x 3cm patch-type sensor fixed to the wrist with a band. Note that the change from the value before bathing was expressed here, and the average value of the data obtained by the subject for 5 days was used.

[0039] As in the case of investigating the correlation between bathing time and blood flow, 210 L of hot water was poured into the bathtub and the bathing temperature was adjusted to 39°C, and the neutral bicarbonate bath additive of this example was added to adjust the bicarbonate ion concentration to 2 mmol / L, and the time change in deep body temperature was measured when 10 subjects (healthy women aged 20 to 60 years) bathed in the bath. For comparison, the time change in body temperature was also measured when 10 subjects bathed in normal hot water at 39°C. The results are shown in Table 4 and Figure 5.

[0040] [Table 4]

[0041] FIG. 5 is a diagram showing the correlation between bathing time and deep body temperature. As shown by the dashed line in FIG. 5, when bathing in normal hot water, the blood flow rate increases due to the action of the autonomic nerves, but the deep body temperature does not rise so much. On the other hand, as shown by the solid line in FIG. 5, when bathing in hot water in which the neutral bicarbonate bath agent of this embodiment is added and the bicarbonate ion concentration is adjusted to 2 mmol / L, the bicarbonate ions are absorbed transdermally and nitric oxide is generated in the blood vessels, and the cyclic guainosine phosphate generated from the nitric oxide relaxes the smooth muscles, expanding the blood vessels and increasing the blood flow rate. As a result, after 10 minutes, the deep body temperature rose by about 0.7°C (about 0.5°C in the case of normal hot water) from the value before bathing, and after 20 minutes, the body temperature rose by about 1.5°C (about 1.1°C in the case of normal hot water) from the value before bathing, and the deep body temperature continued to rise gradually as the bathing time increased. From the results in Figure 5, when bathing in water with dissolved bicarbonate ions, the deep body temperature is clearly higher than when bathing in normal water, and it is clear that bathing in water with dissolved bicarbonate ions warms the body from the core. From the results in Figure 5, considering the significant difference in body temperature compared to when bathing in normal water, it can be said that the optimal bathing conditions are a bathing time of 10 minutes or more, preferably 20 minutes or more, and it was found that when bathing under these bathing conditions, the deep body temperature is about 0.2°C higher than when bathing in normal water.

[0042] Next, we investigated how the deep body temperature before sleep changes when bathing under the above bathing conditions is continuously performed every day. The bath temperature was adjusted to 38°C, the neutral bicarbonate bath agent of this embodiment was added, and 50 subjects (men and women with an average age of 46.8 years) were made to bathe for 30 minutes every day for 4 weeks, and their deep body temperature before sleep was measured. For comparison, 50 subjects were made to bathe for 30 minutes in normal hot water at 38°C every day for 4 weeks, and their deep body temperature before sleep was measured. The results are shown in Table 5 and Figure 6.

[0043] [Table 5]

[0044] FIG. 6 is a diagram showing the correlation between the duration of bathing and the deep body temperature before sleep. As shown by the dashed line in FIG. 6, when bathing in normal hot water, the deep body temperature before sleep only rises by about 0.1°C even if bathing is performed every day for four consecutive weeks. On the other hand, as shown by the solid line in FIG. 6, when bathing in hot water containing the neutral bicarbonate bath agent of this embodiment, the deep body temperature before sleep rises by about 0.2°C after one week, and the deep body temperature remains high thereafter. From the results in FIG. 6, it was found that when bathing in hot water containing dissolved bicarbonate ions, the deep body temperature before sleep can be maintained at a higher level than when bathing in normal hot water, and that by bathing every day for more than one week, the deep body temperature before sleep can be raised by about 0.2°C.

[0045] Next, we evaluated the effect of bathing with neutral bicarbonate bath additives on improving occupational stress. The revised Industrial Safety and Health Act, enacted in June 2014, made it mandatory for companies to conduct stress checks, such as distributing self-administered questionnaires to employees at least once a year, from December 2015. Therefore, we evaluated the effect of improving occupational stress using the Simple Occupational Stress Questionnaire. Figure 7 shows the questions, answers, and scores for the 23-item simple version of the Simple Occupational Stress Questionnaire, which contains questions about stress factors in daily life, physical and mental stress responses, and support from those around you.

[0046] Specifically, subjects (25 people) who took baths in water with dissolved bicarbonate ions using a neutral bicarbonate bath additive for 4 weeks and subjects (25 people) who took baths in normal water for 4 weeks were asked 23 items from the simplified version of the Occupational Stress Simple Questionnaire before and after bathing, and scores were calculated based on their answers. Here, the score before bathing in normal water or water with dissolved bicarbonate ions was designated Stress-B, and the score after bathing in normal water or water with dissolved bicarbonate ions was designated Stress-A, and the rate of change in score (%) was calculated according to the following formula. The results are shown in Tables 6 to 8 and Figure 8.

[0047] Score change rate (%) = (Stress-A - Stress-B) / Stress-B x 100

[0048] [Table 6]

[0049] [Table 7]

[0050] [Table 8]

[0051] As can be seen from Tables 6 to 8 and Figure 8, the rate of change in occupational stress scores for subjects who took regular baths for four weeks was -14.0% for stress factors related to daily life, -18.6% for mental and physical stress responses, and -4.2% for support from those around them, whereas the rate of change in occupational stress scores for subjects who took baths for four weeks in baths in baths with dissolved bicarbonate ions was -16.1% for stress factors related to daily life, -24.5% for mental and physical stress responses, and -11.9% for support from those around them.This shows that by continuing to bathe in baths with dissolved bicarbonate ions, the rate of change in occupational stress scores significantly decreased (the degree of improvement was large), and it was confirmed that bathing with neutral bicarbonate bath additives is effective in improving occupational stress.

[0052] In particular, with regard to the support from those around you in Table 8, the rate of change in the occupational stress score was -4.2% when bathing in normal water, whereas the rate of change in the occupational stress score was -11.9% when bathing in water with dissolved bicarbonate ions, demonstrating a significant effect on improving occupational stress.

[0053] As explained above, it was found that a bicarbonate bath using a neutral bicarbonate bath additive can expand blood vessels through the percutaneous absorption of bicarbonate ions, thereby increasing the degree of reduction in deep body temperature and improving sleep quality, relaxing the mind and body by placing the parasympathetic nervous system in a dominant state, and promoting the supply of nutrients and the removal of fatigue substances by increasing blood flow, and that these physiological functions can improve occupational stress. Furthermore, by performing a bicarbonate bath under appropriate bathing conditions (bath temperature: 29-43°C, bicarbonate ion concentration: 0.1-10mmol / L, bathing time: 10 minutes or more, preferably bath temperature: 32-40°C, bicarbonate ion concentration: 0.2-5mmol / L, bathing time: 20 minutes or more), it is possible to further promote the percutaneous absorption of bicarbonate ions and expand blood vessels, thereby enhancing the above physiological functions and more effectively improving occupational stress. In particular, it was found that a bath using a neutral bicarbonate bath additive can significantly improve stress related to support from those around you (stress related to communication with your boss or colleagues).

[0054] Next, we will explain typical neutral bicarbonate bath additives that can be used in the above-mentioned bicarbonate bath.

[0055] The neutral bicarbonate bath agent used in the bicarbonate bath of this embodiment is a compressed tablet containing a bicarbonate (sodium bicarbonate or potassium bicarbonate) in a predetermined ratio of organic acid, a predetermined ratio of polyethylene glycol, and, if necessary, a predetermined ratio of anhydride (anhydrous sodium carbonate or anhydrous potassium carbonate). For example, it is a compressed tablet containing 1 / 10 to 1 / 3 organic acid, 1 / 100 to 1 / 5 polyethylene glycol, and 1 / 100 to 1 / 10 anhydride (anhydrous sodium carbonate or anhydrous potassium carbonate) in a predetermined ratio of bicarbonate (sodium bicarbonate or potassium bicarbonate), and the pH of the aqueous solution immediately after dissolving the tablet is 5.5 to 8.5.

[0056] Examples of organic acids that can be used include citric acid, succinic acid, and malic acid. By using an organic acid that contains at least citric acid, the neutralization reaction in the tablet can be sustained more effectively and fine bubbles can be generated.

[0057] In addition, when bicarbonate is granulated in a fluidized bed to obtain a granulated product, the reaction in the tablet can be efficiently enhanced by using a mechanical fluidized bed granulator that does not substantially use air for stirring. In a fluidized bed with a mechanical stirring method, air is not used for stirring, and the powder is fluidized using mechanical blades such as a propeller, so there is no absorption of moisture brought in from humid air during granulation.

[0058] Mechanical fluidized bed granulators that do not essentially use air for agitation are mixers that have a plough-like shovel inside a horizontal drum to create centrifugal diffusion and vortex flow effects, resulting in three-dimensional fluidization. For example, they are sold on the market by Deutsche Loedige AG or Matsuzaka Giken Co., Ltd.

[0059] It is more preferable that the granulator is equipped with a vacuum pump for reducing the pressure. By applying a vacuum with a vacuum pump during granulation, the amount of polyethylene glycol can be reduced and granulation can be performed, so that the diameter of the foamed bubbles can be made extremely small while making the neutralization reaction more active. Furthermore, it is preferable that the granulator is equipped with a chopper to prevent the granulated granules from becoming coarse particles when cooled. That is, by operating the chopper during cooling to regulate the size, the effect of making the diameter of the carbon dioxide gas bubbles smaller than micron size is exhibited, which is a more preferable granulation method.

[0060] In the neutral bicarbonate bath agent of this embodiment, sodium bicarbonate is granulated with polyethylene glycol by a fluidized bed granulator using a mechanical stirring method, and a certain ratio of organic acid and polyethylene glycol are added to the granulated product, mixed, and compressed under high pressure to obtain tablets with a certain hardness or a certain size. Of course, a mixture mainly containing organic acid can also be granulated with polyethylene glycol, and bicarbonate is simply mixed with polyethylene glycol without granulation, mixed with organic acid granulated product, and compressed to obtain tablets. This is preferable as a manufacturing method from the viewpoint of process because the amount of compound to be granulated is relatively small. In any case, from the viewpoint of cost, it is desirable to granulate either bicarbonate or organic acid, and to manufacture the product by simply mixing the other. In addition, in order to maintain the neutralization reaction in the tablet for a long time and increase the amount of carbon dioxide gas dissolved, it is a preferable manufacturing method to use both bicarbonate and organic acid salt mixed or coated with polyethylene glycol.

[0061] In addition, in the neutral bicarbonate bath additive of this embodiment, it is preferable to add an anhydride in any step before compression molding. If the amount of anhydride is too large, the amount of foaming bubbles will be small, while if it is too small, carbon dioxide gas will be generated intensively in the bath, which is not preferable. The anhydride is one or more anhydrides selected from anhydrous sodium carbonate and anhydrous potassium carbonate, and anhydrous sodium carbonate is particularly preferable.

[0062] In addition, the neutral bicarbonate bath agent of this embodiment can use a release agent for tablet molding. Generally, sucrose or magnesium stearate is used as the release agent, but it is particularly preferable to include one selected from sodium n-(normal)octanesulfonate, sodium laurylsulfonate, sodium lauroylsarcosinate, sodium myristoylmethylalanine, etc., since the tablet can be compressed and molded stably and quickly. In addition, when the tablet is dissolved in hot water, these release agents are most preferably used to cause micro-sized bubbles and maintain the transparency of the hot water after dissolution. The amount of the release agent added may be within the range of known and used, and there is no particular restriction.

[0063] In addition to the main component, other components (additives) can be mixed into the neutral bicarbonate bath additive of this embodiment as needed. Other additives include health components such as hyaluronic acid, fragrances, colorings, vitamin C, and reducing substances that remove chlorine from tap water (sodium ascorbate, amino acids, sodium sulfite, sodium thiosulfate), etc.

[0064] The present invention is not limited to the above-described embodiment, and the configuration can be modified as appropriate without departing from the spirit of the present invention.

[0065] For example, in the above examples, a bicarbonate bath was described in which the tablet invented by the present inventors was used as a neutral bicarbonate bath additive, but if a bath additive is used that can dissolve bicarbonate ions in the water to the same extent and make the water with the bicarbonate bath additive dissolved therein approximately neutral, the same effect of improving occupational stress can be obtained. [Industrial Applicability]

[0066] INDUSTRIAL APPLICABILITY The present invention can be used for a method for improving occupational stress, in particular, for a method for improving occupational stress by taking a bath using a bicarbonate bath additive. [Explanation of symbols]

[0067] 1 epidermis 2 Dermis / subcutaneous adipose tissue 3 Pores 4. Sweat pores 5 blood vessels 6 Blood vessel wall 7 Smooth Muscle 8 Vascular endothelial cells 9 Intravascular

Claims

1. A method for improving occupational stress by bathing with a bicarbonate bath additive, comprising: The bicarbonate bath agent contains a bicarbonate salt consisting of sodium bicarbonate or potassium bicarbonate and an organic acid as a composition, and the mixing ratio of the composition is set so that hot water containing the bicarbonate bath agent dissolved therein is approximately neutral; The occupational stress is improved by the physiological function based on the dilation of blood vessels caused by the percutaneous absorption of bicarbonate ions dissolved in the hot water. A method for improving occupational stress.

2. The bathing conditions are that the temperature of the water is 29 to 43°C, the concentration of bicarbonate ions dissolved in the water is 0.1 to 10 mmol / L, and the bathing time is 10 minutes or more. The method for improving occupational stress according to claim 1.

3. The bathing conditions are that the temperature of the water is 32 to 40° C., the concentration of bicarbonate ions dissolved in the water is 0.2 to 5 mmol / L, and the bathing time is 20 minutes or more. The method for improving occupational stress according to claim 1.

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