In the second part with Prof. Russell Foster (Head of the Nuffield Laboratory of Ophthalmology, and Director of the Sleep and Circadian Neuroscience Institute at the University of Oxford), contributing to the Daylight Awareness Week (13-17th of November 2023), we continue our discussion around the differential impact of daylight and electric light on health. We provide a historical perspective about human inventions that aimed to end the dependency on daylight - from fire to electric lighting. Prof. Foster further shares practical recommendations on how daylight and electric light can support health and well-being. Lastly, he gives an outlook on where the research around lighting and health is heading to in the future.

More information about the Daylight Awareness Week: ⁠https://daylight.academy/daylight-awareness-week-2023/

Chapters:

(0:00:00) Intro & Recap of Part 1

(0:02:36) History of inventing fire & candles

(0:08:22) Rise of electric light & disruption

(0:15:15) Sensitivity to light at night

(0:22:03) Dominance of LEDs nowadays

(0:23:07) Interim conclusion

(0:27:18) Practical recommendations for evening lighting

(0:30:37) Architectural dilemma with daylight

(0:33:12) Early birds vs. Night owls

(0:37:35) Jet lag

(0:40:10) Drug development for blind people

(0:42:11) Mimick seasonal changes in daylight

(0:45:29) Russell’s personal outlook

(0:55:02) Funny anecdotes

(0:59:26) Outro

Papers/books that Russell refers to:

A. Roger Ekirch's book: “At Day's Close”

Thomas Wehr's research on bimodal or polymodal sleep:

"In short photoperiods, human sleep is biphasic" (Wehr 1992)

https://doi.org/10.1111/j.1365-2869.1992.tb00019.x

Russell's group - investigation on international populations, night owls were missing morning light

"Chronotype and environmental light exposure in a student population" (Porcheret et al. 2018)

https://doi.org/10.1080/07420528.2018.1482556

Charles Czeisler’s group - full-intensity kindle watching for 4 hours for 5 nights

"Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness" (Chang et al. 2014)

https://doi.org/10.1073/pnas.1418490112

Prior light exposure of 500-600 lux during the day abolished the suppressing-melatonin-effect

"The effects of prior light history on the suppression of melatonin by light in humans" (Hebert et al. 2002)

https://doi.org/10.1034%2Fj.1600-079x.2002.01885.x

Harvard group: aged humans show decreased sensitivity to light

"Decreased sensitivity to phase-delaying effects of moderate intensity light in older subjects" (Duffy et al. 2007)

https://doi.org/10.1016/j.neurobiolaging.2006.03.005

Christian Cajochen’s work on alertness, blue light is most important

"High Sensitivity of Human Melatonin, Alertness, Thermoregulation, and Heart Rate to Short Wavelength Light" (Cajochen et al. 2005)

https://pubmed.ncbi.nlm.nih.gov/15585546/

Arti Jagannath's work on jet lag:

SIK1 deletion in mice and jet lag:

"The CRTC1-SIK1 pathway regulates entrainment of the circadian clock" (Jagannath et al. 2013)

https://doi.org/10.1016/j.cell.2013.08.004

Recent review on SIK:

"The multiple roles of salt-inducible kinases in regulating physiology" (Jagganath et al. 2023)

https://doi.org/10.1152/physrev.00023.2022

How to contact Russell Foster:

Email: russell.foster@eye.ox.ac.uk