Light heals!

The sun, the main source of light on Earth, controls not only the change of day and night, but also biorhythms in the organisms of all mammals, including humans. Biorhythms are known to regulate our sleep, nutrition, sexual desire and mental activity. “It is light that controls the biological clock in our body,” emphasizes somnologist François Duforez. – For example, autumn depression is directly related to the shortening of daylight hours. It manifests itself in lethargy, drowsiness, lack of energy. This seasonal ailment is relieved by special intense lamps, under which patients spend at least an hour a day.

The jet lag syndrome, or jet lag, is also directly related to light. Pilots and flight attendants restore jet lag by taking melatonin. It is also prescribed for autistic children who have difficulty falling asleep. That is why melatonin is usually called the sleep hormone, although the name “messenger of light” is more suitable for it. “It reflects the alternation of day and night. Its production increases when the sun sets. And it stops in the morning,” says Francois Duforet. Through this hormone, the heavenly body controls many basic functions of our body: the period of wakefulness and sleep, body temperature, hormone production.

The sun helps you lose weight

Neuroscientists at the University of Chicago were surprised to find that walking during daylight hours or under bright lights makes you slim (1). Especially if you are in the sun in the morning. It’s all about melatonin again. Its production is directly related to the synthesis of insulin, a hormone that controls blood glucose levels. In diabetic patients, both insulin and melatonin are deficient, and therefore often superficial sleep. Light also normalizes the metabolism of glucose in the body and gradually reduces weight.

But a dream with a bright nightlight, a computer screen turned on or without thick curtains, on the contrary, contributes to a set of kilograms. This conclusion was reached by scientists from Oxford (2), who observed 13 women for 40 years. The body mass index and waist size of the participants in the experiment increased along with the increase in the level of illumination of their bedrooms at night. With comparable nutrition and sleep duration, those who slept in more lit bedrooms over the years became fuller than those who slept in the dark.

American scientists have found that too intense night light contributes to the appearance of prostate cancer in men and breast cancer in women. Darkness during sleep, on the contrary, increases the effectiveness of chemotherapy in breast cancer (3). The fact is that melatonin, the production of which increases if at least the eyes are pricked around, inhibits the growth of cancer cells.

But our eyes are not the only windows through which the healing power of the light pours in upon us. The skin also absorbs the sun’s rays, under the influence of which the body forms vitamin D, which is necessary for bones and the immune system. The sun soothes the manifestations of psoriasis during an exacerbation, as well as some other skin diseases. UVA helps reduce stress: Sunbathing changes the levels of carbon dioxide naturally found in the skin, causing blood vessels to dilate and lowering blood pressure (4).

Read more:

• Morning light helps you lose weight

Antimicrobial robot

Natural light is a small part of the vast spectrum of electromagnetic waves that we can see. Modern medicine has technologies that allow the use of waves of only the wavelength that is needed in each case. For example, ultraviolet A rays are used by dermatologists to treat psoriasis, and by cardiologists to determine the condition of the heart. In addition, they have antibacterial properties. For example, the US-made Little Moe robot, equipped with a xenon lamp, disinfects hospital wards and ambulances in which people infected with the Ebola virus were transported in a few minutes. In the central hospital of the French town of Angers, red light lamps have been installed for the treatment of prostate tumors, which in some cases make it possible to avoid surgery. Red lamps are also used in cardiac surgery and skin grafting. At the experimental level, American researchers managed to place light-sensitive receptors on the surface of cells. This gave them the ability to use light to control individual cells and entire neural circuits, as well as regulate the functioning of heart cells (5).

Blue LED against bad memories

However, the real star of research labs is blue light. It was the invention of his source that was awarded the Nobel Prize in 2014. “This is a technological revolution. Blue LED lamps have allowed medicine to move to a new stage in the use of light therapy,” says François Duforet. One possibility is that light can improve cognition, attention, and focus. In the winter of 2013, François Duforet and his colleague Damien Léger watched for several weeks during the winter of 6 a XNUMX-year-old child in a classroom equipped with the Philips School Vision system. In the first hour of the morning and after lunch, the teacher turned on intense saturated blue light (lamps in the “Energy” mode). At the end of the class, the light turned warmer, orange, to relieve tension and help the children relax before returning home (Comfort mode). “Our observations have shown that blue-white light helps children focus for longer periods of time. At the same time, it does not cause lethargy after work and does not lead to sleep disturbances, ”says Francois Duforet. Studies by Swedish scientists (XNUMX) have also confirmed that blue light improves memory, speeds up reactions and fills you with energy no worse than a cup of freshly brewed coffee.

The blue light guides us into the future, building a strong bridge between body and soul. The new science of optogenetics explores the work of nerve cells by introducing special channels into their membrane that respond to excitation by light. Thus, scientists are striving to find new treatments for certain mental disorders. For example, the Brain Institute team has used optogenetics to reduce compulsive disorders in mice (7), which holds promise for a therapy to treat obsessive-compulsive disorders in humans. Last August, Japanese scientists stated that blue light could alter the negative emotions associated with bad memories (8). At the moment, studies in mice are ongoing. The study of the effect of blue on humans is planned to begin in five to ten years.

1. PLoS One, 2014, April.

2. E. McFadden and al. «The Relationship Between Obesity and Exposure to Light at Night: Cross-Sectional Analyses of Over 100,000 Women in the Breakthrough Generations Study», American Journal of Epidemiology, 2014, May.

3. Cancer Research, 2014, June.

4. The data was published at the International Congress of Dermatologists in Edinburgh in May 2013.

5. PNAS, 2012, November.

6. PLoS One, 2013, November.

7. T. Kim and al. «Injectable, Cellular-Scale Optoelectronics with Applications for Wireless Optogenetics» Science, 2013, June.

8. E. Callaway «Flashes of light show how memories are made», 2014, August.