A 50 Hz magnetic field affects hemodynamics, ECG and vascular endothelial function in healthy adults: A pilot randomized controlled trial

Abstract

Application of exposure to 50/60 Hz magnetic fields (MFs) has been conducted in the treatment of muscle pain and fatigue mainly in Japan. However, whether MFs could increase blood flow leading to muscle fatigue recovery has not been sufficiently tested. We investigated the acute effects of a 50 Hz sinusoidal MF at Bmax 180 mT on hemodynamics, electrocardiogram, and vascular endothelial function in healthy young men. Three types of regional exposures to a 50 Hz MF, i.e., forearm, upper arm, or neck exposure to MF were performed. Participants who received three types of real MF exposures had significantly increased ulnar arterial blood flow velocity compared to the sham exposures. Furthermore, after muscle loading exercise, MF exposure recovered hemoglobin oxygenation index values faster and higher than sham exposure from the loading condition. Moreover, participants who received real MF exposure in the neck region had significantly increased parasympathetic high-frequency activity relative to the sham exposure. The MF exposure in the upper arm region significantly increased the brachial artery flow-mediated dilation compared to the sham exposure. Computer simulations of induced in situ electric fields indicated that the order-of-magnitude estimates of the peak values were 100–500 mV/m, depending on the exposure conditions. This study provides the first evidence that a 50 Hz MF can activate parasympathetic activity and thereby lead to increase vasodilation and blood flow via a nitric oxide-dependent mechanism. Trial registration: UMIN Clinical Trial Registry (CTR) UMIN000038834. The authors confirm that all ongoing and related trials for this drug/intervention are registered.

A role of cryptochrome for magnetic field‐dependent improvement of sleep quality, lifespan, and motor function in Drosophila

“…(a) Relationship between magnetic flux density and distance from the center of a magnetic field (MF) coil. The MF strength decays with distance from the coil (Okano et al, 2021). (b) Examination of optimal conditions for health promotion.…”

“…(a) Relationship between magnetic flux density and distance from the center of a magnetic field (MF) coil. The MF strength decays with distance from the coil (Okano et al, 2021) do this, we estimated magnet field decay with distance from the AC magnetic field generator (Figure 1a). In this way, AC magnetic field intensity is gradually attenuated with distance from the field generator.…”

System-level biological effects of extremely low-frequency electromagnetic fields: an in vivo experimental review

“…In recent years, EMF therapy has gained significant interest due to its potential protective impact on cardiovascular functions, and various in vivo experiments on humans have been conducted. For instance, a pilot randomized controlled trial on healthy adults showed that a magnetic field of 50 Hz had therapeutic effects to stimulate parasympathetic activity, resulting in enhanced vasodilation and blood flow through a nitric oxide-dependent mechanism (Okano et al, 2021 ). A double-blind, repeated study explored the effect of ELF-EMFs on heart rate (HR) and HR variability and found a reduction in HR caused by the possible enhancement of parasympathetic predominance by short-term EMF (Binboga et al, 2021 ).…”

Electromagnetic field and cardiovascular diseases: A state‐of‐the‐art review of diagnostic, therapeutic, and predictive values

“…Recently, a prospective, randomized, sham‐controlled study (UMIN Clinical Trial Registry [CTR] UMIN000038834) involving healthy young men examined the acute effects of a 50 Hz EMF on hemodynamic responses. In addition to significant increases in ulnar artery blood flow due to regional exposure to EMF, the results of the flow‐mediated dilation (FMD) test demonstrated an increase in NO production and NO‐mediated vasodilation under exposure to EMF exposure 27 . Shear stress can induce the expression of COX‐2/PGI 2 in endothelial cells, which plays a crucial role in maintaining thromboembolic equilibrium 28 .…”

“…In addition to significant increases in ulnar artery blood flow due to regional exposure to EMF, the results of the flow-mediated dilation (FMD) test demonstrated an increase in NO production and NOmediated vasodilation under exposure to EMF exposure. 27 Shear stress can induce the expression of COX-2/PGI 2 in endothelial cells, which plays a crucial role in maintaining thromboembolic equilibrium. 28 In a FeCl 3 -induced thrombosis, which is related to platelet activation and coagulation system activation, various intensities of exposure to SMF were tested (200, 400, and 600 mT), the results showed that SMF with an intensity of 600 mT significantly increased PAI (plasminogen activator inhibitor) and tPA (tissue-type plasminogen activator) activity and decreased the content of thrombus protein content.…”