Artificial light, all of the health risks - The Sciences

Into The increasingly intense and prolonged exposure to artificial light after sunset is closely associated with sleep deprivation, a condition that predisposes to health problems such as obesity, diabetes and cardiovascular disease. And the spread of LED lights can make the situation worse (red)

From technological breakthrough in health risk: this would be the historical parable of artificial light according to an opinion piece that appeared in the pages of “Nature” written by Charles Czeisler, of the department of Sleep Medicine at Harvard Medical School.

Artificial light is one of the factors most strongly associated with sleep deprivation, a very common condition in our society and that is one of the risk factors for pathological conditions that are becoming more epidemic proportions, such as obesity, diabetes, cardiovascular disease, depression and stroke.

Exposure to light of a screen is a risk factor for sleep deprivation and then for conditions such as obesity ( © Tom Grill / Corbis)
Recent research in this field, conducted both on the animal model is directly in humans, have shown for example that stay awake longer alters the expression of hundreds of genes. At the behavioral level, it is seen rather than the prolonged wakefulness causes you to eat more, well beyond the energy needs of the organism. And there are measurable effects on the immune system: to keep his balance, the body needs an adequate number of hours of sleep per night.

Even more obvious are the effects on the mental faculties: to be Most affected are attention span, concentration and learning, and even moo d can pay the price, in addition, it causes an increase in the state of anxiety and depression that some studies have even linked to a higher rate of suicide.

To complain of an insufficient number of

hours of sleep (typically the threshold for adults is six hours per night), according to statistics is now about one-third of Americans are active adults, while only 3 percent 50 years ago. Not be better for children, it is true, as the data show, that in the world the children sleep on average 1.2 hours per night in less than a century ago.

The causes of this shift are patt ‘another sought in the social trend to move more and more towards the production of goods and services 24 hours a 00:07 days a week, the results of which are evident from studies of individuals who work on night shifts. But it is not to be neglected sleep deprivation voluntary and recreational activities, such as staying awake watching television.

The growth of light pollution in Italy (courtesy www.lightpollution.it) In all this, the role of artificial light is rarely emphasized, but it is fundamental as well as the ear has two functions, the hearing and the balance, the eye has, besides the function of vision, also to transmit to the brain, via the ganglion cells of the retina, the informati on about the presence of ambient light, the most important of the signals that regulate the circadian rhythms, our “internal clock”.

Once in the brain, these signals trigger a series of different effects: inhibit neurons that promote sleep, suppress the release of the hormone melatonin, which is important for the regulation of the sleep-wake cycles by the pituitary, and activate orexin neurons in the hypothalamus that promote wakefulness.

So the overall picture is as follows: the human being has evolved according to circadian rhythms regulated on natural light. But a little more than a century after sunset the lights artificial, reproducing even at night the signals that are peculiar of the day. And the phenomenon is more intense and pervasive, to the point that in areas inhabited almost total darkness no longer exists: artificial lighting is now being allocated 19 percent of the energy produced in the world.

The components of blue-green spectrum of the wealth of the LED lights activate more than other brain mechanisms that boost the waking ( © Ryan Palmer / Science Faction / Corbis) And the more we illuminate the darkness, summarizes Czeisler, much less sleep. Mor eover, the advent of LED lighting, more efficient than the classic incandescent bulbs and halogen bulbs also, will only make things worse. The white LED light has a wealth of blue-green parts of the spectrum, which are precisely those that are most sensitive ganglion cells in the retina. Result: the artificial lighting will report more and more to our brain that is not yet time to sleep, and this will do their part also televisions and computer monitors, some years are also based on LED technology.

Into Fortunately, the mechanisms by which the artificial light suppresses sleep are more and more clear, and this also helps to remedy this effect: for example, we are already thinking to correct the blue-green component of LED lights with a ‘emission shifted to the yellow-orange hue. But there’s nothing we can do all the effort to organize our day in a different way, perhaps avoiding to remain in front of a screen until the wee hours.