Color therapy changes blood oxygenation in the brain and muscle

Introduction

In anthroposophic medicine art therapies such as color therapy (CT) are applied for various medical conditions. The aim of this pilot study was to investigate possible effects of CT hemodynamics and tissue oxygenation in the brain and skeletal leg muscle measured by near infrared spectrophotometry (NIRS).

Materials and methods

Ten subjects (5 male, 5 female, age mean 27 range 23–44 years) were measured during CT. The measurement included 8min without color exposure (baseline), 10min color exposure to intensive red or blue light followed by 16min without exposure during recovery. Each subject was measured twice, once exposed to red, once to blue in a randomized crossover protocol. A Hamamatsu NIRO 300 NIRS instrument was used to non-invasively measure total hemoglobin concentration (tHb in μM) and tissue oxygen saturation (StO2 in %). By a paired t-test the last 5min of pre-baseline were compared to the first and last 5min of the color exposure, and three periods of 5min of recovery. Blue and red exposures were compared by a paired Wilcoxon signed rank test.

Results

In the leg, the tHb concentration increased significantly and continuously during and after exposure by up to (mean±SEM) 1.08±0.19μM (p=0.0002) for blue and 1.52±0.33μM (p=0.0013) for red. Although StO2 did not change significantly compared to baseline, after exposure to blue StO2 was significantly (p=0.0371) higher than during red exposure.

In the head tHb did not change significantly, while StO2 increased significantly during blue exposure by 0.51±0.21% (p=0.0367), with a maximum shortly after exposure 0.98±0.40% (p=0.0324). During red exposure StO2 changed little and not significantly. The increase in StO2 during exposure to blue was significantly different (p=0.0488) from red.

The findings for the muscle can be interpreted as an increase in blood volume and a decrease in oxygen consumption for blue compared to red exposure. For the head blue specifically increases oxygenation without increasing blood flow.

Conclusion

The results show that CT has effects on important physiological parameters and that these effects depend on the color that the subject is exposed to.