We don’t live close to Nature and its rhythms anymore; we live in artificial environments, where all we need is a switch to instantly turn night into day. Nowadays exposure to blue lights is increasingly frequent.
We have the habit of falling asleep in front of a screen, while watching a film or looking at our phone as the last – detrimental – thing we do in our day.
Children start using electronic devices earlier and earlier, and they get used to a prolonged use right from the start. Even homework is often done on a computer, and they spend their free time playing videogames with their virtual friends for hours on end.
What may constant exposure to light entail?
As claimed by Professor Pierpaoli, constant exposure to light can have harmful consequences. The Professor studied these effects through an experiment: mice specimen were kept under permanent artificial lighting. The specimen reproduced for four generations: the first two did not exhibit any issues, while the third started to show some problems.
The most dramatic effects were more manifest in the fourth and last generation. The mice showed damages to their immune and hormone system, they aged prematurely and developed cancer.
The effects of this “chronic light” took a lot of time to show, proving the fact that circadian rhythms are permanently imprinted in our DNA.
The quantity of light affects the pineal gland’s capacity to produce melatonin. To confirm this, the experiment showed that the lighting the subjects were constantly exposed to completely abolished the production of this important molecule.
The importance of natural lighting
Light has a dual effect on melatonin’s rhythms: if, on one hand, it restores its rhythm, on the other hand, if darkness periods are eliminated, it can suppress its entire secretion. We can’t do away with electric lighting; however, we could at least use a type of lighting similar to natural lighting.
Sunlight is defined as warm, and it has certain characteristics: an average light colour temperature between 2700 – 2800° Kelvin and a spectrum measured as Ra in its complete range (colour rendering index) where all colours can be distinguished.
The lighting systems in our homes and offices should be as close as possible to these values. For instance, the old filament bulbs (now very hard to find) and new-generation halogen bulbs are those that come closest to those values.
Some neon lights (except for penta-phosphorous and three-phosphorous) and LED lights are great for cost savings, but they don’t meet the criteria of sunlight-similar lighting. Lights tending to blue – those used in electronic devices – should be avoided, because they alter our colour perception.
The role of light in our rhythms
In its evolution, man developed hormonal programs dictated by light and temperature. These external signals are perceived by our body, which transmits them to our systems, organs and cells. The Pineal gland – sensitive to light –reacts to the light-darkness succession transmitted by the eyes.
«Differently from animals, which are susceptible to Nature’s whims, we humans are not anymore. Thanks to modern commodities, such as electric lighting and air conditioning, we can control the environment surrounding us, to some extent.»
However, in some cases, and in relation to certain disorders, using a light with specific characteristics can be very beneficial
1.Pierpaoli, W.,Yi, C.X. and Dall’Ara, A. Aging-postponing effects of circadian melatonin: experimental evidence, significance and possible mechanisms. Int. J. Neurosci. 51, 339-340, 1990.
2.Pierpaoli, W. The pineal aging clock. Evidence, models and an approach to aging-delaying strategies. In: Aging, Immunity and Infections (Edited by Powers, D.C., Morley, J.E. and Coe, R.M.) pp. 166-175. Springer Publishing Company, New York, 1994.
3.Simone Secchi, Fondamenti di illuminotecnica naturale e artificiale, http://web.taed.unifi.it/fisica_tecnica/dispense/fond_luce.pdf