Natural Light
Image credit: balanchel
In a previous blog we covered how the shorter days, reduced light and changes in our lifestyles throughout autumn can have a negative impact on our vitamins D levels however, they can also have a profound effect on our circadian rhythm, melatonin and serotonin levels [1-3]. Melatonin is an important hormone that helps regulate the endocrine system and helps you sleep while serotonin is often referred to as the ‘happy hormone’ and helps to stabilise our mood. Therefore, a lack of light during the autumn and winter months can have a negative impact on our lives by effecting our sleep, impacting our menstrual cycles, sperm production, our appetite, mood and may increase the incidence or severity of SAD [4-6; 7-12; 13-14; 15; 16,17].
5 ways you can improve your light exposure during the colder months to support your wellbeing.
Time outside come rain or shine, as it approaches the end of autumn here in the UK (20th December) and the cold of winter is setting in, prioritise some time for exposure to natural daylight, it may not look bright but those dull days still offer essential light and could help to support optimal sleep, appetite, mood and more. So make the most of what sunlight there is throughout the day, just 10 minutes a couple of times a day can make a huge difference, aim for morning, noon and dusk.
Prioritise daily walks - ensuring you get in your daily steps can increase your light exposure and can additionally support your metabolism.
Reduce blue light exposure during the evenings, just as we need the light during the day, blue light can also play havoc with our circadian rhythm, melatonin production and sleep as it simulates day light and can trick our brains in thinking it is still day time [18-22]. Some studies suggests that wearing blue light glasses is a great way to combat this without the need to turn off your TV and disconnect too early on an evening [23,24]. However, you may also like to think of turning off technology and screens a little earlier and try reading a book or listening to your favourite podcast to switch off in the last hour or so before bed.
Light therapy boxes - if you really can’t get outdoors or you are suffering from a condition that is impacted by your light exposure and are feeling getting outdoors is not enough consult your GP they may suggest a light therapy box, that has been reported to have positive effects on may conditions.
Stay happy and healthy,
Chel
References
Berson, D.M. et al. (2002) Phototransduction by retinal ganglion cells that set the circadian clock. Science, 295(5557), pp.1070-1073.
Lambert, G.W.,et al. (2002) Effect of sunlight and season on serotonin turnover in the brain. The Lancet, 360(9348), pp.1840-1842.
Young, S.N. (2007) How to increase serotonin in the human brain without drugs. Journal of psychiatry & neuroscience: JPN, 32(6), p.394.
Smolensky, M.H. et al. (2015) Nocturnal light pollution and underexposure to daytime sunlight: Complementary mechanisms of circadian disruption and related diseases.
Pandi-Perumal, S.R. et al. (2008) The roles of melatonin and light in the pathophysiology and treatment of circadian rhythm sleep disorders. Nature clinical practice neurology, 4(8), pp.436-447.
Boubekri, M., et al. (2014) Impact of windows and daylight exposure on overall health and sleep quality of office workers: a case-control pilot study. Journal of clinical sleep medicine, 10(6), pp.603-611.
Baker, F.C. and Driver, H.S. (2007) Circadian rhythms, sleep, and the menstrual cycle. Sleep medicine, 8(6), pp.613-622.
Danilenko, K.V., et al. (2011) Menstrual cycles are influenced by sunshine. Gynecological Endocrinology, 27(9), pp.711-716.
Shechter, A. and Boivin, D.B. (2010) Sleep, hormones, and circadian rhythms throughout the menstrual cycle in healthy women and women with premenstrual dysphoric disorder. International journal of endocrinology, 2010.
Parry, B.L., et al. (1997) Plasma melatonin circadian rhythms during the menstrual cycle and after light therapy in premenstrual dysphoric disorder and normal control subjects. Journal of Biological Rhythms, 12(1), pp.47-64.
Davis, S. et al. (2012) Night shift work and hormone levels in women. Cancer Epidemiology and Prevention Biomarkers, 21(4), pp.609-618.
Marino, J.L. et al. (2008) Shift work, hCLOCK T3111C polymorphism, and endometriosis risk. Epidemiology (Cambridge, Mass.), 19(3), p.477.
Liu, M.M. et al. (2017) Sleep deprivation and late bedtime impair sperm health through increasing Antisperm antibody production: a prospective study of 981 healthy men. Medical Science Monitor: International Medical Journal of Experimental and Clinical Research, 23, p.1842.
Luboshitzky, R. et al. (2001) Disruption of the nocturnal testosterone rhythm by sleep fragmentation in normal men. The Journal of Clinical Endocrinology & Metabolism, 86(3), pp.1134-1139.
AlBreiki, M. et al. (2015) The effect of light on appetite in healthy young individuals. Proceedings of the Nutrition Society, 74(OCE1).
Mind (2019) ‘Seasonal affective disorder (SAD)’ Available at: https://www.mind.org.uk/media-a/2952/sad-2019.pdf (Accessed: 30th November 2020).
Magnusson, A. and Boivin, D. (2003) Seasonal affective disorder: an overview. Chronobiology international, 20(2), pp.189-207.
Cajochen, C. et al. (2011) Evening exposure to a light-emitting diodes (LED)-backlit computer screen affects circadian physiology and cognitive performance. Journal of applied physiology, 110(5), pp.1432-1438.
Figueiro, M.G. et al. (2011) The impact of light from computer monitors on the melatonin levels in college students. Biogenic Amines, 25(2), pp.106-116.
Holzman, D.C. (2010) What’s in a color? The unique human health effects of blue light.
Duffy, J.F. and Czeisler, C.A. (2009) Effect of light on human circadian physiology. Sleep medicine clinics, 4(2), pp.165-177.
Gooley, J.J. et al. (2011) Exposure to room light before bedtime suppresses melatonin onset and shortens melatonin duration in humans. The Journal of Clinical Endocrinology & Metabolism, 96(3), pp.E463-E472.
Wood, B. et al. (2013) Light level and duration of exposure determine the impact of self-luminous tablets on melatonin suppression. Applied ergonomics, 44(2), pp.237-240.
Sasseville, A. et al. (2006) Blue blocker glasses impede the capacity of bright light to suppress melatonin production. Journal of pineal research, 41(1), pp.73-78.