Effects of Water-Soluble Silicon Intake on Blood Pressure and Stress Improvement
- KIWITA
- Jan 15
- 8 min read
Updated: Jan 18
Improvement of Blood Pressure and Stress Response Following Ingestion of Water-Soluble Silicon
Article Type: Original Article Taiki Jimbo¹, Norimi Okada²
Reiwa Medical Research Institute, Reiwa Medical Research Co., Ltd.
APA Corporation Co., Ltd.
Keywords: Water-soluble silicon, functional ingredients, lifestyle-related diseases, blood pressure, stress
Abstract
Silicon exists in various forms and is generally classified into crystalline silicon and amorphous silicon. The silicon used in Japan as a food additive and health food is amorphous, water-soluble silicon. In the human body, silicon is found in bones, joints, blood vessels, hair, and other tissues, and is involved in processes such as dental plaque removal by saliva and various metabolic turnover processes. Approximately 30 mg of silica is consumed daily by adults; however, since silicon cannot be synthesized endogenously, it must be obtained from external sources. Silicon is abundantly present in foods such as brown rice, millet, bananas, and raisins, and is also commercially available as a health food added to drinking water, with expected health benefits.
Although various health effects are anticipated, most evidence regarding silicon’s efficacy in humans has been extrapolated from animal studies. Animal experiments have primarily demonstrated effects on bones and blood vessels, including suppression of hypertension and improvement of related gene expression. However, evidence regarding its effects in humans remains limited, and further accumulation of scientific evidence is required to substantiate the diverse functional properties attributed to silicon.
Against this background, the present study investigated changes in blood pressure, stress response, fatigue, and autonomic nervous system balance in human subjects following ingestion of water-soluble silicon. Blood tests were also conducted to evaluate safety. As a result, improvements in blood pressure and stress response were observed without any adverse events, and these findings are reported herein.
Introduction
Silicon is known to exist in multiple forms and is commonly classified into crystalline and amorphous silicon. The silicon used in Japan as a food additive or health food is amorphous and water soluble.
In the human body, silicon is present in bones, joints, blood vessels, hair, and other tissues, and plays a role in dental plaque removal via saliva as well as in various metabolic turnover processes. Approximately 30 mg of silica is consumed daily by adults; however, because silicon cannot be synthesized within the body, it must be obtained from dietary sources. Silicon is abundant in foods such as brown rice, millet, bananas, and raisins, and is also commercially available as a health food added to drinking water, with anticipated health benefits. Nevertheless, despite these expectations, evidence supporting its efficacy in humans remains largely limited to animal studies.
Animal studies have reported effects mainly on bones and blood vessels, including suppression of hypertension and improvement of aortic gene expression in spontaneously hypertensive rats (1,2), increased bone density with higher silicon intake (3), enhanced bone strength (4), induction of immune responses following silicon intake (5), vasodilatory effects (6), and suppression of body weight gain in mice (7,8). However, sufficient data regarding the physiological effects and functional properties of silicon in humans have yet to be established.
In light of this background, the present study evaluated changes in blood pressure as well as immune and stress responses by measuring salivary sIgA and salivary cortisol levels (9–12). Additionally, subjective fatigue and sleep quality were assessed using questionnaires (13–15). Autonomic nervous system function was analyzed using acceleration plethysmography (16), and vascular age was also estimated using the same method to assess vascular effects. Although no adverse events related to silicon intake have been reported to date, blood tests were additionally conducted as a precautionary measure to reassess safety.
Through these assessments, this study aimed to collect fundamental evidence regarding the functional properties of water-soluble silicon and to explore potential areas for future research. As a result, improvements in blood pressure and stress response were observed and are reported herein.
Methods
Participants
Participants were publicly recruited based on the following inclusion criteria:
Men and women aged 20–64 years at the time of informed consent
Individuals who received a full explanation of the study objectives and procedures, demonstrated the capacity to consent, fully understood the study, and voluntarily provided written informed consent
Exclusion Criteria
Individuals meeting any of the following criteria were excluded:
Currently receiving pharmacological treatment for chronic diseases
Individuals with a history of severe food allergies
Pregnant individuals or those with the possibility of pregnancy
Participation in another human clinical trial at the time of enrollment or within the preceding three months
Excessive alcohol consumption
Individuals with hepatic, renal, cardiac diseases, respiratory disorders, endocrine disorders, metabolic disorders, neurological disorders, consciousness disorders, diabetes, or other conditions making study participation difficult
Individuals deemed unsuitable for participation by the investigators
Number of Participants
A total of 12 participants (mean age: 41.08 ± 1.73 years) were enrolled. No participants withdrew from the study, and no adverse events attributable to the study were observed.
Study Design
Participants were recruited through public invitation. After receiving a full explanation of the study and providing informed consent, participants ingested the test food: water-soluble silicon umo® concentrated solution (provided by APA Corporation), at approximately 9 mL per day for a total of six weeks. The solution was consumed by adding 3 mL each to water or tea after breakfast, lunch, and dinner.
Assessments were conducted before the intervention (Visit 1) and after the intervention (Visit 2), as described below, to observe changes in participants’ physical and mental conditions. Adherence to the intervention and any significant changes in health status during the study period were monitored using check sheets. Statistical analysis was conducted after completion of all assessments.
Assessment Items
I. Medical Interview and Questionnaire-Based Assessments
Basic information including name, sex, age, height, weight, body temperature, test food intake status, sleep duration, medical history, regular medications, smoking status, alcohol consumption, dietary habits, and blood pressure
Visual Analog Scale (VAS) for subjective fatigue assessment (13)
Holmes Stress Response Scale for subjective stress assessment (15)
OSA Sleep Inventory for sleep quality assessment (14)
Adherence check sheet results
Health condition monitoring during intake
Post-study impressions (free-text and multiple-choice responses)
Responses before and after the intervention were collected and analyzed.
II. Measurement of Salivary Stress Markers
Measurements were conducted using a dedicated assay kit (SOMA CUBE, SOMA Bioscience). A small amount of saliva was collected using the provided swab, dissolved in a measurement solution, applied to a measurement chip, and analyzed optically to quantify cortisol and sIgA levels (9–12).
III. Blood Test Analysis
Blood samples were analyzed for the following parameters: total protein, ALP, AST, LDH, γ-GTP, total bilirubin, LDL cholesterol, HDL cholesterol, triglycerides, Na, K, Cl, Ca, P, Mg, blood urea nitrogen, creatinine, eGFR, blood glucose, albumin, HbA1c, red blood cell count, white blood cell count, hemoglobin, hematocrit, platelet count, MCV, and MCH.
IV. Acceleration Plethysmography
Autonomic nervous system balance and vascular age were estimated using acceleration plethysmography with TAS9VIEW (YKC Corporation) (16).
The timing of each assessment is illustrated in Figure 1.
Statistical Analysis
All statistical analyses were performed using IBM SPSS Statistics 20.0 and its add-on modules. The Wilcoxon signed-rank test was applied, with a significance level set at 5%.
Ethical Considerations
This study was conducted after approval by the Ethics Review Committee of the Japan Health Promotion Association (Approval No. 20230915-1).
Results
Medical interviews and questionnaire results revealed significant reductions in stress magnitude and stress response scores on the Holmes Stress Response Scale (Figure 2). No significant differences or trends were observed in other questionnaire items. Post-study free-text comments were collected as shown in Table 1. In the multiple-choice survey, favorable subjective effects such as “feeling more energetic” and “improved blood pressure” were frequently reported (Figure 3).
Physiological measurements showed significant reductions in both diastolic and systolic blood pressure (Figure 4). Acceleration plethysmography revealed a significant decrease in SDNN and a significant increase in PSI, reflecting changes in autonomic nervous system balance (Figure 5).
Blood tests showed significant decreases in MCHC, albumin, albumin/globulin ratio, and eGFR, as well as significant increases in sodium and calcium levels; however, all values remained within normal reference ranges and were not considered clinically significant.
Discussion
Although this study has limitations due to its short intervention period (six weeks) and small sample size (12 healthy individuals), significant improvements were observed in several parameters. Subjective assessments and post-study impressions indicated a significant reduction in stress response. While there are few human studies reporting stress-reducing effects of water-soluble silicon, the findings are consistent with anecdotal reports suggesting stress alleviation.
More than half of the participants reported feeling more energetic after the intervention. However, acceleration plethysmography indicated increased physical fatigue, as reflected by increased PSI and decreased SDNN. Despite this, participants reported improved subjective well-being and reduced stress responses, suggesting a perceived improvement in mental and physical resilience.
Additionally, both systolic and diastolic blood pressure were significantly reduced. Similar antihypertensive effects have been reported in animal studies, and the present findings are consistent with previous reports suggesting blood pressure regulation via genetic modulation. Approximately half of the participants also subjectively reported improved blood pressure, suggesting that water-soluble silicon may be useful for hypertension prevention and daily health management.
While the study scale was limited, observable improvements in blood pressure and stress response were noted. Future studies with larger sample sizes are needed to further evaluate the functional properties of water-soluble silicon, including potential sex-based differences.
Conclusion
The results of this study suggest that intake of water-soluble silicon may contribute to improvements in blood pressure and stress response.
Figures and Tables
Figure 1: Study timeline
Figure 2: Changes in Holmes Stress Response Scale
Table 1: Free-text responses after study completion
Figure 3: Distribution of subjective post-intervention impressions
Figure 4: Changes in blood pressure
Figure 5: Changes in autonomic nervous system indices measured by acceleration plethysmography
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Note: This paper is translated from the following URL. The content is provided for reference on the scientific research of the raw material only. Whether APA raw materials are used or not, we hope this research will help increase understanding and awareness of body minerals.
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