Light impacts our behaviour all the time, whether we're working or relaxing, whether we're awake or asleep. We see two converging pathways in circadian lighting development:
University-based research
University research is painstaking and expensive to fund, both in financial cost and time. But that research helps to deliver "hard" criteria against which design can develop.
Evidence-based exploration
Real-world projects, often developed on a "best guess" basis are vital in supporting pure research. There is always "evidence" - though it can be surprising.
The Headline Issues
The wake-up call: circadian entrainment
The word Circadian comes from the Latin meaning ‘around a day’. Your internal day-night cycle - or circadian rhythm, evolved to make sure your body and brain are primed and ready for the conditions you are likely to find in the outside world. A tiny yet vital nucleus in the centre of the brain called the central pacemaker, uses the rhythmic shifts in lighting conditions from bright days to dark nights as a critical time-keeping signal to keep your internal clock on track.
This regular pattern drives a cascade of physiological responses, including the regulation of hormones such as melatonin as well as alertness and mood. As we get older, changes in our eyes mean that less light reaches the central pacemaker and hormone signalling becomes weaker. To compound the issue, these critical neural structures are affected by degenerative diseases such as dementia. It can be even harder for those living in Residential Care to keep their body clocks on track as they often lack other time-keeping cues such as physical activity and social interaction. ‘Circadian lighting’ is an approach to day and night-time lighting that delivers the essential shifts in intensity and spectrum that the central pacemaker needs to maintain a healthy 24-hour cycle.
- Brown, T. M., Brainard, G. C., Cajochen, C., Czeisler, C. A., Hanifin, J. P., Lockley, S. W., Lucas, R. J., Munch, M., O'Hagan, J. B., Peirson, S. N., Price, L. L. A., Roenneberg, T., Schlangen, L. J. M., Skene, D. J., Spitschan, M., Vetter, C., Zee, P. C., & Wright, K. P., Jr. (2022). Recommendations for daytime, evening, and nighttime indoor light exposure to best support physiology, sleep, and wakefulness in healthy adults. PLoS Biol, 20(3), e3001571.
https://doi.org/10.1371/journal.pbio.3001571
Time for bed: a recipe for a good night's sleep
Sleep is one of the most obvious signs of a healthy body clock. Sleep is especially critical for those living in Residential Care as there is a clear link with a range of physical and mental health conditions from depression, anxiety and cognitive decline to weakened immune response, cardiovascular health and muscle strength. Lighting that actively supports circadian entrainment has been shown to improve mood and memory, and reduce 'sundowning' agitation, infections, night-time wandering and falls. These effects extend beyond Residents to staff, who note reduced workload at night and even an improvement in their own physical and mental health. (1) (2) (3) (4) (5)
- Trošt Bobić, T., Šečić, A., Zavoreo, I., Matijević, V., Filipović, B., Kolak, Ž., Bašić Kes, V., Ciliga, D., & Sajković, D. (2016). The Impact of Sleep Deprivation on the Brain. Acta Clin Croat, 55(3), 469-473.
https://doi.org/10.20471/acc.2016.55.03.17 - Calkins, M. (2018). From Research to Application: Supportive and Therapeutic Environments for People Living With Dementia. The Gerontologist, 58, S114-S128.
https://doi.org/10.1093/geront/gnx146 - Grant, L. K., St Hilaire, M. A., Heller, J. P., Heller, R. A., Lockley, S. W., & Rahman, S. A. (2022). Impact of Upgraded Lighting on Falls in Care Home Residents. J Am Med Dir Assoc, 23(10), 1698-1704.e1692.
https://doi.org/10.1016/j.jamda.2022.06.013 - Kolberg, E., Hjetland, G. J., Thun, E., Pallesen, S., Nordhus, I. H., Husebo, B. S., & Flo-Groeneboom, E. (2021). The effects of bright light treatment on affective symptoms in people with dementia: a 24-week cluster randomized controlled trial. BMC Psychiatry, 21(1), 377.
https://doi.org/10.1186/s12888-021-03376-y - van Lieshout-van Dal, E., Snaphaan, L., & Bongers, I. (2019). Biodynamic lighting effects on the sleep pattern of people with dementia. Building and Environment, 150, 245-253.
https://doi.org/https://doi.org/10.1016/j.buildenv.2019. 01.010
COMMON GROUND: MAY 2023
The future of circadian lighting in the care home sector
In May 2023, Age of Light Innovations arranged a one-day symposium of design experts and care home management working in the care home sector to discuss the 'common ground' that exists between science, technology and practical care home management.
The symposium was recorded and we present it here. click on the title bar below: