Medical Psychology & Medical Sociology, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.
Department of Psychosomatic Medicine and Psychotherapy, University Medical Center of University Cologne, Cologne, Germany.
Stress. 2021 May;24(3):331-337. doi: 10.1080/10253890.2020.1803265. Epub 2020 Aug 10.
Research studies on LED light exposure and cortisol are inconsistent and not comparable due to different types of light, exposure times, and sample sizes. Therefore, one hour of standardized exposure LED light at different intensities and the spectral composition during the post-awakening phase at 7:30 were compared. A sample of 23 (Study 1) and 26 (Study 2) healthy males were randomly assigned to: 1) bright white light (414 lux) and 2) dim darkened light (<2 lux) as well as 3) red light (235 lux) and 4) blue light (201 lux) exposure conditions. Results from repeated measures ANOVA confirm that light exposure affects the cortisol concentration. Study 1 revealed an increase in the saliva cortisol concentration after bright light exposure compared to dim light. An increase in the cortisol concentration of blue light compared to red light (Study 2) and dim light was found. This study shows that bright light and blue light affect the cortisol response in contrast to dim light and red light conditions. The HPA axis showed a stimulatory effect by bright versus dim light and different wavelengths of light exposure.Lay summaryThe effects of LED light exposure on the stress hormone cortisol were investigated. The light exposure took place during the hours people would start working at the office. The results showed that after one hour of exposure to bright light or blue light the stress hormones increase in contrast to dim light and red light conditions. Thus, stress hormones can be altered by the types of light people are exposed to.
关于 LED 光暴露和皮质醇的研究结果不一致，且不可比，因为涉及到不同类型的光、暴露时间和样本量。因此，比较了在觉醒后阶段 7:30 以不同强度和光谱组成进行的标准化 1 小时 LED 光暴露。随机分配了 23 名（研究 1）和 26 名（研究 2）健康男性参与者到以下条件：1）明亮的白光（414lux）和 2）昏暗的暗光（<2lux），以及 3）红光（235lux）和 4）蓝光（201lux）暴露条件。重复测量方差分析的结果证实，光暴露会影响皮质醇浓度。研究 1 显示，与暗光相比，明亮光暴露后唾液皮质醇浓度增加。与红光（研究 2）和暗光相比，蓝光暴露后皮质醇浓度增加。本研究表明，与暗光和红光条件相比，明亮光和蓝光会影响皮质醇反应。HPA 轴显示出明亮光与暗光以及不同波长光暴露的刺激作用。
简而言之：本研究调查了 LED 光暴露对应激激素皮质醇的影响。光暴露发生在人们开始在办公室工作的时间。结果表明，与暗光和红光条件相比，暴露于明亮光或蓝光一小时后，应激激素会增加。因此，人们所接触的光的类型可以改变应激激素。
