Excess blue light also causes inflammation and mitochondrial dysfunction, primarily because of its impact on glucose control. In the evening, exposure to blue light causes a peak in glucose levels, leading to higher blood sugar and an increase in insulin resistance.1 This means your blood sugar is higher than it should be, and your body doesn’t adequately move that sugar out of your bloodstream. The result is that you are at a greater risk of weight gain2 and developing type 2 diabetes

1. Bhagyesh R. Sarode et al., “Light Control of Insulin Release and Blood Glucose Using an Injectable Photoactivated Depot,” Molecular Pharmacology 13, no. 11 (November 7, 2016): 3835–41, https://doi.org/10.1021/acs.molpharmaceut.6b00633; Marla Paul, “Exposure to Bright Light May Alter Blood Sugar,” Futurity, May 19, 2016, https://www.futurity.org/bright-light-metabolism-1166262–2/.

2. Nataliya A. Rybnikova, A. Haim, and Boris A. Portnov, “Does Artificial Light-at-Night Exposure Contribute to the Worldwide Obesity Pandemic?,” International Journal of Obesity 40, no. 5 (May 2016): 815–23, https://doi.org/10.1038/ijo.2015.255.)