The Importance of Full Spectrum Lighting in the Health and Productivity of Workers: Duro-Test Vita-Lites Simulate Natural Light.
It is reasonable to suggest that if full spectrum lighting is installed in the workplace, this would have a positive effect on the symptoms of those who are susceptible to SAD (Seasonal Affective Disorder) and increase their performance.
The region of the body that is most influenced by natural light, and has the greatest physiological effect is the pineal gland, a prominent secretory organ which synthesizes a number of exocrine and endocrine substances.
The Importance of Full Spectrum Lighting in the Health and Productivity of Workers
Excerpted from International Academy of Chiropractic Occupational Health Consultants, Vol. 9, No.3
"Like bears, squirrels, and birds, humans have evolved under the sun. We have incorporated into the machinery of our bodies the rhythms of day and night, of darkness and light, of cold and warmth. Over hundreds of thousands of years, the architecture of our bodies has been shaped by the seasons, and we have developed mechanisms to deal with the regular changes that they bring. We continue to respond to these rhythms in the way we feel and behave. For some of us however, the changes can disrupt our lives."
This quote from the book, Winter Blues, by Norman E. Rosenthal, is a vivid reminder of how during our quests for education and success in our occupations, we tend to isolate ourselves from nature. However, we can never isolate ourselves from the intimate effects nature has had on our evolution as human beings, and the dependency our bodies have on the subtle effects of nature.
The region of the body that is most influenced by natural light, and has the greatest physiological effect is the pineal gland, a prominent secretory organ which synthesizes a number of exocrine and endocrine substances. Its structure is very similar to that of the retina of the eye and acts as a direct photosensory organ. The pineal gland is controlled by the amount of light seen by the eyes each day. The pineal influences thermoregulation, electrolyte metabolism, intermediary metabolism, hemopoiesis, immune system and behavior. It is also considered as one of the most important components of the vertebrate circadian system and is a principle source of rhythmically produced melatonin.
Melatonin has recently gained intense popularity among the public for its effect as a sleep aid as well as other benefits reported. This naturally occurring hormone is released from the pineal gland in response to darkness. It helps in regulation of the sleep/wake cycle, and is thought to play a role in increased immune function.
Research has shown conclusively that light affects the human body in ways other than producing vision. The effects identified so far involve body rhythms. Full spectrum light, of sufficient high intensity will suppress the secretion of melatonin at night in humans.
As humans increasingly confine themselves in institutions and offices for the pursuit of educational and/or occupational success, the increasing isolation from natural sunlight, incongruent with our bodies' natural processes, (an evolution of hundreds of thousands of years), has been recognized. Thus the invention of artificial full spectrum lighting for indoors is our response to counteract this deficiency.
Research suggests that the pineal glands in the brains of some people are more highly sensitive to the loss of natural light, resulting in a host of symptoms, generally described as a "hibernation reaction" in the most sensitive of cases. Some of the more significant symptoms range from depression to sluggishness to carbohydrate-craving to loss of motivation to seeing everything in a negative light and interpreting the actions of others in the same manner.
One of the more commonly known conditions resulting from lack of natural sunlight is Seasonal Affective Disorder (SAD). SAD is triggered by the shortening of the photoperiod as winter approaches. The shortened photoperiod allows melatonin, the hormone responsible for signaling that it's time to sleep, to build up to higher-than-normal levels in the blood, which in turn produces the symptoms of SAD. Much of the physiology behind SAD also plays a role in our daily sleep/wake cycle. When this cycle is disrupted, we get the symptoms of jet lag: clinical sleep disorders, severe fatigue, major digestive problems, and the inability to react or concentrate.
How is our sleep/wake cycle disrupted? Our bodies expect to receive a daily stimulus of light every morning from sunlight at sunrise. That the sunrise is the key stimulus of light makes sense when we realize that the rising and setting of the sun has for eons been the major daily environmental stimuli in the evolution of life. If we don't receive these signals, or we receive them at the wrong time, several physiological cycles desynchronize or are phase-shifted, causing jet lag symptoms. So while we do have internal clocks (pacemakers), they need to be reset daily. The prime pacemaker is a pair of very small organs in the hypothalamus, called the SupraChiasnic Nuclei (SCN). The SCN wants to "free-run" at about a 25-hour cycle: the sunrise entrains it to a 24 hour cycle. The SCN signals the pineal to start producing melatonin at the proper time - dusk. It is reasonable to suggest that a person working a rotating shift schedule, the night shift, or simply does not receive these signals due to isolation from natural light, can live in a state of perpetual disynchrony.
Along with a host of people diagnosed and suffering with the symptoms of SAD, there is an even greater number of people walking around with these symptoms occurring in varying degrees, which will no doubt affect their ability to function optimally and perform optimally in the workplace.
It is important to point out that current lighting standards are NOT based on health and well-being, but on task performance and energy use. Manmade, full-spectrum lighting will never fully replace the natural light of the sun - no more than a vitamin synthesized in a lab can replace natural vitamin value from a food source. Our findings suggest a link between lack of natural light or full spectrum lighting and the health and well-being of the individual. It is reasonable to suggest that if full spectrum lighting is installed in the workplace, this would have a positive effect on the symptoms of those who are susceptible and increase their performance.
Reprinted from June 1997 Texas Journal of Chiropractic
Duro-Test Vita-Lite and Vita-Lite Plus have a color rendering index (CRI) of 91, sunlight has a CRI of 100, most cool white fluorescent lights only have a CRI of 62.