In our report, Understanding Seasonal Affective Disorder, we have seen how artificial bright light can be used to treat the condition. In this post we’ll look at the science behind how bright light therapy works – and why you should probably consider using full-spectrum lighting in your home, office, or workplace to improve productivity and to give your immunity a boost…
In “Light Medicine of the Future,” Jacob Liberman, O.D., Ph.D, cites a 1980 study that was done by Dr. Fritz Hollwich which compared the effects of sitting under strong artificial cool-white (non-full spectrum) illumination versus the effects of sitting under strong artificial illumination that simulates sunlight (full-spectrum).
Dr. Hollwich used changes in the endocrine system to evaluate these effects and he found that the levels of ACTH and cortisol ( one of the stress hormones) in individuals sitting under the cool-white tubes was of the same level of magnitude as that found in people undergoing mild or moderate stress.
These changes were totally absent in the individuals sitting under the sunlight-simulating tubes.
“The significance of Hollowich’s findings becomes clear when the functions of ACTH and cortisol are examined. Both of these metabolic hormones play major roles in the functioning of the entire body and are very much related to the stress response.”
“Since the activity of ACTH and cortisol increases inhibitors [within the system], this may account for the observation that persistent stress stunts bodily growth in children.”
“Hollowich’s findings clarify and substantiate the observations of Ott and others regarding the agitated physical behavior, fatigue, and reduced mental capabilities of children. He concluded that the degree of biological disturbance and the resulting behavioral mal-adaptations were directly related to the difference between the spectral composition of the artificial source and that of natural light.”
“Since cool-white fluorescent lamps are especially deficient in the red and blue-violet ends of the spectrum, this may explain why color therapists have historically used a combination of the colors red and blue-violet as an emotional stabilizer.”
“Hollwich’s work not only confirms the biological importance of full-spectrum lighting, but it also reconfirms the importance of specific colors by evaluating the effects of their omission from our daily lives.”
“It has been found that full-spectrum lighting in the work place creates significantly lower stress on the nervous system than standard cool-white fluorescent lighting and reduces the number of absences due to illness.”
“These findings seem to indicate that full-spectrum lighting may act to boost the immune system in the same way as natural sunlight.”
Artificial indoor lighting has improved a lot in recent years with the introduction of cold-fluorescent lighting in the 1990s, and LED (light-emitting diode) lighting since, but for all that a lot of us still use less-than-optimal light levels in our homes and workplaces.
To give you an example, in some of these studies above, people were exposed to light levels as high as 20 times the intensity of normal indoor lighting!
“…the light approximated the sensation of sitting on a shady porch or under a tree in mid-summer.”
The researchers found that “sufficiently intense light suppresses the secretion of this chemical [melatonin], making it a useful marker in determining light’s physical effect on behavior.”
The secretion of melatonin reflects light’s effect on the hypothalamus, which is highly sensitive to light. This complex part of the brain regulates a multitude of body functions, playing a vital role in reproduction, thirst, hunger, satiation, temperature, emotions, and sleep patterns. Depression is associated with disturbances in the hypothalamus.
It’s small wonder then that sub-optimal lighting in our homes, offices, and workplaces could adversely impact our immunity, not only to emotional disturbances, but also to our ability to combat infections and disease.
As the COVID pandemic and its lockdowns have shown, lack of exposure to natural lighting has been blamed for all sorts of health problems, including eyesight problems.
“Conventional indoor lighting lacks the proper proportion of near-UV radiation of the sun that advocates claim to be vital to health and well-being.”
Full-spectrum artificial light is widely used to cure a potentially fatal type of infant jaundice. We need sunlight with its UV rays to metabolize vitamin D, necessary for the absorption of calcium, especially in growing children and the elderly.
Some studies show that working under true full-spectrum lights enhances productivity and reduces fatigue. Even critics concede that many people who are deprived of natural light, such as night or shift workers, suffer undue emotional stress.
So, given all this, should you get out now and flood your workspace or your home with bright lighting?
Caution is in order here… Bright light can damage the retina and UV can be dangerous, so you need to illuminate these spaces with lighting that is optimal but not excessive – preferably using lamps that have been formulated based on scientific research. (Read our Carex Bright Therapy Lamp Review)
The best advice on leveraging light for health and productivity comes from Dr. Richard Wurtman, professor of endocrinology and metabolism at the Massachusetts Institute of Technology.
He said, “We should not take artificial lighting for granted. Light is potentially too useful an agency of human health not to be more effectively examined and exploited.”