E7 - Part 1: How to use & avoid light to optimize health with Samer Hattar
Episode description
Dr. Samer Hattar (Chief of the Section on Light and Circadian Rhythms at the National Institute of Mental Health, Bethesda, MD, USA) talks about tools to exploit natural daylight and avoid artificial light after sunset to optimize health. In this first part, Samer shares practical recommendations on how to integrate daylight better into our everyday life. We discuss physiological mechanisms at play how light influences human physiology. We extensively cover the topic of blue-blocking glasses, which can be a good or a bad thing depending on time of day, and elaborate on differences between glasses. We further acknowledge many things that we don't know about how light influences us humans.
Link to Samer’s episode on the Hubermanlab Podcast:
Dr. Samer Hattar: Timing Light, Food, & Exercise for Better Sleep, Energy & Mood | Huberman Lab #43
https://www.youtube.com/watch?v=oUu3f0ETMJQ
Papers that Samer and I refer to:
Restricted feeding uncouples circadian oscillators in peripheral tissues from the central pacemaker in the suprachiasmatic nucleus (Damiola et al. 2000)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC317100/
External light activates hair follicle stem cells through eyes via an ipRGC–SCN–sympathetic neural pathway (Fan et al. 2018)
https://www.pnas.org/doi/abs/10.1073/pnas.1719548115
The effects of extended photoperiod and warmth on hair growth in ponies and horses at different times of year (O’Brien et al. 2020)
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0227115
The influence of bright and dim light on substrate metabolism, energy expenditure and thermoregulation in insulin-resistant individuals depends on time of day (Harmsen et al. 2022)
https://doi.org/10.1007/s00125-021-05643-9
Diurnal Blood Pressure Variations Are Associated with Changes in Distal–Proximal Skin Temperature Gradient (Kräuchi et al. 2012)
https://www.tandfonline.com/doi/full/10.3109/07420528.2012.719961
High Sensitivity of Human Melatonin, Alertness, Thermoregulation, and Heart Rate to Short Wavelength Light (Cajochen et al. 2005)
https://academic.oup.com/jcem/article/90/3/1311/2836588
Brain regions that receive light information, 53 brain regions are responsive in nocturnal mice:
Feature Detection by Retinal Ganglion Cells (Kerschensteiner 2022)
Entrainment of the Human Circadian Clock to the Natural Light-Dark Cycle (Wright et al. 2013)
https://www.sciencedirect.com/science/article/pii/S0960982213007641?via%3Dihub
Depressed Patients Hospitalized in Southeast-Facing Rooms Are Discharged Earlier than Patients in Northwest-Facing Rooms (Gbyl et al. 2016)
https://www.karger.com/Article/FullText/477249
Divergent outer retinal circuits drive image and non-image visual behaviors (Beier et al. 2022)
https://www.sciencedirect.com/science/article/pii/S2211124722007926
Red light can change the state of the melanopsin photo pigment:
Melanopsin Tristability for Sustained and Broadband Phototransduction (Emanuel & Do 2015) https://www.sciencedirect.com/science/article/pii/S0896627315001002
Samer Hattar on Social Media:
Twitter: @SamerHattar
NIH-Homepage: https://www.nimh.nih.gov/research/research-conducted-at-nimh/principal-investigators/samer-hattar