I. HEALING THROUGH DAYLIGHT

I. HEALING THROUGH DAYLIGHT

THE SUNSHINE VITAMIN

Daylight’s benefits are innumerous. Firstly, sunlight exposure is crucial for receiving vitamin D, a vitamin boasting a number of positive outcomes: regulating absorption of nutrients in the small intestine and kidneys, facilitating absorption of calcium and phosphorus (Elements that support development of bone tissue and structure), and reinforcing the body’s immune system (Boubekri, 65-75). Hence its nickname of “the sunshine vitamin,” skin absorbs sunlight in order to gather and harness vitamin D and gain its benefits (Boubekri, 65). In case daylighting strategies are somehow not an option due to factors such as obscure locations and darker skin tones, patients would need to rely on medical supplements and dietary sources instead (Boyce, 43). Be that as it may, vitamin D is an essential element of the human body; one better absorbed than ingested.

The amount of time necessary for someone to photosynthesize vitamin D ranges anywhere from 15 minutes to three hours a day, three or four times per week (Boubekri, 80). On top of that, any sort of glazing filters out roughly 95% of the sun’s ultraviolet rays; as a result, gaining proper exposure to photosynthesized vitamin D takes longer indoors than outdoors (Boubekri, 81). With this in mind, designers should optimize windows and glazing in a way that gives occupants continuous and consistent daylight, so as to maximize vitamin D absorption and other supplements.

In photosynthesis, skin absorbs ultraviolet rays from daylight and processes it into vitamin D, a nutrient highly beneficial for human health (Chaudhuri, 32).

Unfortunately, some suffer from a lack of vitamin D through an illness called hypovitaminosis D. For instance, hospital patients, especially bedridden ones vacating rooms for extended periods of time, often suffer from this shortage (Boubekri, 66). Factors such as an inadequate exposure to sunlight and seasonal variations are particularly detrimental to vitamin D absorption (Boubekri, 68). Hypovitaminosis D is also more common during the end of the winter season, as days are short and sunlight exposure becomes minimal (Boubekri, 68).

The result correlates with bone frailty, such as hip fractures within older people (Boubekri, 68). Along with that, this deficiency may lead to a variety of debilitating illnesses, such as rickets, osteomalacia, and several forms of cancer, including colon, breast, ovarian, and prostate (Boyce, 43). Therefore, healthcare design should adjust with its environment and combat this ailment by maximizing daylight intake.

In photosynthesis, skin absorbs ultraviolet rays from daylight and processes it into vitamin D, a nutrient highly beneficial for human health (Chaudhuri, 32).

Vitamin D is also more prevalent through natural light than electrical fixtures. Sunlight has a specific CCT, or Correlated Color Temperature, that bolsters its ability to channel vitamin D, among other health-related benefits (Boubekri, 79). On the other hand, however, artificial lights can simulate this specific CCT and other visual qualities to match the sun’s benefits, stretching as far as liver health (Boubekri, 80). These lights could be helpful for occupant well-being during the nighttime, but gathering sunlight during the day is optimal for health and energy conservation.

For all its uses, however, there is a balancing act involving vitamin D and sunlight. For an example, people who wear sunscreen outdoors absorb a significantly lower amount of the vitamin; without sunscreen or any other protective means of blocking ultraviolet rays, however, they risk of overexposure to the same solar radiation (Boyce, 43). Factors include infancy, photosensitivity, visual ailments, and skin damage or cancer (Boyce, 42-43). These are significant enough to warrant the concern of patients and physicians, the latter of which suggest the following: To combat vitamin D deficiency, spending 5 to 30 minutes exposing arms and legs to sunlight between 10:00 AM and 3:00 PM is generally sufficient (Chaudhuri, 34).

Considering these concerns and issues, the answer to granting daylighting’s benefits, including vitamin D production, is not just to expose occupants to as much sunlight as possible; rather, design strategies should display some restraint in order to stimulate vitamin D absorption occupants while avoiding creating new problems in turn.

RADIANT RELIEF

Along with producing vitamin D, natural light helps to alleviate pain. For instance, a study in 2005 showed that patients who underwent elective cervical and lumbar spinal surgeries experienced significant improvement with regards to post-operative pains and aches. Compared to those vacating dim-lit spaces, patients residing in spaces with higher sunlight intensity (i.e. An average increase of 46%) took 22% less analgesic medication per hour, resulting in 21% lower medication costs (Joseph, 6). Patients experienced “less perceived stress” and “marginally less pain,” but the fact that they used less medication after surgery on average proves daylight’s contribution to soothing post-surgical aches (Joseph, 6).

Referring back to vitamin D absorption, photosynthesized nutrients combat diseases such as osteomalacia and rickets (Chaudhuri, 33). To specify, rickets is the name of abnormal bone formations resulting from an insufficient amount of calcium in the body; this disorder is especially common in children (Boubekri, 63). In turn, rickets causes osteomalacia, a general “softening” and weakening of the patient’s bone structure (Boubekri, 63). Vitamin D photosynthesis helps prevent or treat such conditions, serving as another way for daylight to mitigate disease or surgery-induced pain.

STRESS & ANXIETY

Daylight’s effects on stress involve two specific biochemicals: Cortisol and serotonin. The former is a chemical that, within stable levels, sustains proper glucose metabolism, blood pressure, insulin release for blood sugar maintenance, and maintains a proper immune system (Boubekri, 60). Too much, however, may lead to high blood pressure and sugar levels, increased likelihood of female infertility, and a weakened immune system (Boubekri, 60). Poorly regulated cortisol also relates to disorders such as cancer, depression, and Alzheimer’s disease (Boubekri, 60).

Meanwhile, serotonin regulates chemicals that, in excess, may cause mental issues such as depression, bulimia, anorexia, obsessive-compulsive disorder (OCD), and social anxiety (Boubekri, 55).

Daylight stimulates both of these chemicals to create alertness without adding stress as a side effect. For an example, office workers close to a window gain high but stable levels of cortisol and serotonin during summer mornings; as a result, they become more alert without feeling anxious (Boubekri, 60-61). Another study explored the advantages of natural light over artificial fixtures in terms of cortisol release, as summarized in the chart to the right (Boyce, 63). Overall, daylight exposure is an important and natural means of managing stress.

Morning cortisol at four different times of the year in four classrooms (Boyce, 64):

A) Windows and warm white fluorescent tubes

B) Skylight and daylight fluorescent tubes

C) Windowless and warm white fluorescent tubes

D) Windowless and daylight fluorescent tubes

SLEEP & SUNLIGHT

Circadian rhythms and sleep patterns are another important aspect to consider regarding sunlight. Many suffer from a lack or delay of sleep, resulting in later awakenings, stunted energy, and less alertness and productivity during the day (Boyce, 47-48). Luckily, daylight is an effective tool for inducing stable sleeping and waking patterns, as shown in various medical studies and surveys. For instance, adults’ sleep patterns improved during exposure to white or red lights consecutively over 12 days; awakenings during sleeping periods decreased by an hour, and sleep efficiency increased from 77.5% to 90% (Joseph, 5).

A comparison between test subjects’ perception of sleepiness (Bottom Graph) to their actual melatonin levels after spending 2.5 hours exposed to direct light pulse treatment (Cajochen, 13).

This is not the only instance, however; another example shows the effects of exposing patients to a bright light pulse of 5,000 lux for two and a half hours, as shown in the chart above (Cajochen, 13). The study consisted of a single person undergoing a regulated “nap protocol” under two separate conditions: One with the assigned light exposure, and the other without it (Cajochen, 13). Results showed that light exposure and sleep patterns directly correlate with internal body temperatures and melatonin levels, both of which bright light exposure deeply alters (Cajochen, 11). This significant shift once again demonstrates the importance of light exposure to circadian patterns and rhythms.

DAYLIGHT & DISORDERS

Raw hourly activity data of a patient with Alzheimer’s disease over five days, before (Upper panel), during (Middle panel), and after (Lower panel) bright light treatment. The right panels show the average activity levels over 48 hours for 22 subjects with various forms of dementia for the same light exposure conditions (Boyce, 52).

Alzheimer’s disease and dementia are two other psychological disorders treatable by daylight. They are both ailments that deeply stunt memory and cognitive function (Boyce, 50). Due to needing constant supervision, patients receive insufficient daylight since they generally spend little time outdoors; in fact, one proposed solution is to “increase the general illuminance to a higher level in rooms where patients spend their days” (Boyce, 50-51). In fact, two case studies explore the effects of consistent lighting conditions on patients suffering from such illnesses.

The first focused on the effects of special glazing and electronic controls for maintaining consistent light intensity on patients; supervisors found a significant drop in disruptive behavior and agitation among those who underwent treatment (Joseph, 6).

The next study demonstrated the effects of bright morning light on dementia patients; supervisors exposed elderly patients to 2,500 lux per 2 hours in the morning over two 10-day periods; as a result, the patients’ agitation decreased significantly (Joseph, 6). These patients quickly growing erratic again on nontreatment days only bolsters the conclusion that sunlight affects stress and mental disorders in a positive manner, once again showcasing daylight’s effectiveness (Joseph, 6).

SEASONAL AFFECTIVE DISORDER

Daylighting also combats Seasonal Affective Disorder (SAD), a psychological ailment that causes symptoms such as drastic mood swings, stunted energy, and depression (Boubekri, 56). Scientists discovered this in 1984 after learning that improvement in patients’ depression relates to light exposure more than melatonin inhibition; in fact, medical suppression of excessive melatonin did not help matters any (Boubekri, 56-57). It is for this reason light therapy, natural or electrical, is a common method for treating SAD, what with its high success rate of 80% (Boubekri, 60). This treatment is preferable with sunlight instead of artificial devices due to its unique CCT, as mentioned earlier regarding vitamin D absorption (Boubekri, 79).

Similar to vitamin D photosynthesis, daylight’s effectiveness towards mitigating SAD largely depends more on the longevity of exposure than its intensity or magnitude (Boubekri, 60). Biological responses to “bright light” normally begin within two to four days, resulting in significant improvements in a week; regression quickly begins after active light-based therapy or treatment ends (Boyce, 49). In terms of both physical and mental welfare, daylight exposure in building design (e.g. Healthcare) should prioritize consistency over potency.

A graphic comparing how long and at what time(s) of the day SAD patients spend outdoors (Bottom Graph) to the same parameters for healthy subjects (Top Graph) (Boubekri, 59).

DIABETES

Sunlight also helps treat diabetes, a disease involving high blood sugar and beta cells not producing enough insulin (Boubekri, 77). In fact, diabetes stems from a lack of vitamin D alongside other major diseases such as colon, breast, and ovarian cancer (Boyce, 43). Therefore, photosynthesis not only connects with vitamin D, but helps suppress active and debilitating diseases such as diabetes as well.

With diabetes, blood sugar (Glucose) overwhelms sparse amounts of insulin, creating a multitude of health problems. In response, sunlight helps stimulate insulin secretion to regulate blood sugar lvvels (“3D Medical Animation Still of Type One Diabetes”).

Daylight reverses the effects of diabetes, as its production of vitamin D stimulates insulin secretion (Boubekri, 77). Multiple studies explored on the exact process behind this: Vitamin D absorbed either through sun (i.e. Food or vitamin supplements), regulates carbohydrates, or sugar, within the blood stream (Boubekri, 77). In summary, blood sugar levels act inversely proportional to vitamin D, a nutrient best consumed through daylight.

One case study demonstrated the effects of sunlight on diabetic women (Boubekri, 77). Statistically, the sun produces up to 20,000 IU (International Units) worth of vitamins a day; this vastly exceeds the 1,332 IU necessary to increase insulin production by 43% and decrease insulin resistance by 21.4% (Boubekri, 77). This link between diabetes and vitamin D makes for another benefit of daylight, specifically for diabetic patients.

SOOTHING SIGHTS

Daylighting is not the only healing factor to consider; views through apertures also prove to be very effective for occupant well-being, particularly in healthcare architecture. For an example, a study in 1972 revealed that patients are much less likely to suffer from post-operative delirium, a condition that occurs after anesthetic surgery and causes irritability and restlessness (Collins, 28-30). Supervisors concluded that, in providing an outdoor view, windows give the patients a sort of psychological escape after such a major procedure (Collins 28-30).

Meanwhile, another study, lasting from 1972 to 1981, unveiled daylit view’s effects on recovery time. More specifically, hospitalized patients with a window facing a tree spent an average of a day less in recovery than those with a window view of a brick wall (Farley, 11-12). The study demonstrated that a natural view with elements such as open space and greenery fares much better than one in a more enclosed and industrial or urban setting.

From a design perspective, vertical glazing is helpful not just for daylighting, but for outdoor views as well; contrast this with glazing types such as skylights or atria, which mostly provide daylight alone. In healthcare settings, outdoor views are crucial.

RECOVERY TIMES

Referring back to daylighting, a different study revealed that patients who previously underwent heart surgery (i.e. Myocardial infarctions) spent less time in recovery in daylit rooms than in duller ones; namely, patients in the former room spent an average of 2.3 days in recovery, while those in the latter remained in the hospital for an average of 3.3 days (Joseph, 5). Another study in the UK showed that 263 heart surgery patients (i.e. Coronary artery bypass graft surgery) spent 7.3 less hours in recovery per 100-lux increase in daylight (Joarder, 435). Lastly, a 2001 study saw bipolar and depressive patients in east-facing rooms (i.e. Rooms more open to bright morning light) spending an average of 3.67 less days in the hospital compared to those in west-facing rooms (Joseph, 5).

BIBLIOGRAPHY

Boubekri, Mohamed. Daylighting, Architecture and Health: Building Design Strategies. 1st ed., Architectural Press, 2008.

Boyce, Peter & Hunter, Claudia & Howlett, Owen. (2003). The Benefits of Daylight through Windows. California Energy Commission.

Cajochen C., Chellappa S.L., Schmidt C. (2014) Circadian and Light Effects on Human Sleepiness–Alertness. In: Garbarino S., Nobili L., Costa G. (eds) Sleepiness and Human Impact Assessment. Springer, Milano.

Chaudhuri, Kanad & Ashok, Leburu & Sujatha, GP. (2015). The Sunshine of Life: Vitamin D. International Journal of Oral Health Sciences. 5. 30. 10.4103/2231-6027.171171.

Collins, Belinda. Windows and People: A Literature Survey. U.S. Government Printing Office, 1975.

Farley, KMJ, and Jennifer Veitch. A Room with a View: A Review of the Effects of Windows on Work and Well-Being. National Research Council of Canada. 2001.

Joarder, AR & Price, A. (2013). Impact of Daylight Illumination on Reducing Patient Length of Stay in Hospital After Coronary Artery Bypass Graft Surgery. Lighting Research and Technology. 45. 435-449. 10.1177/1477153512455940.

Joseph, Anjali. “The Impact of Light on Outcomes in Healthcare Settings.” The Center for Healthcare Design, 2 Aug. 2006.

IMAGE CREDITS

“3D Medical Animation Still of Type One Diabetes.” Wikipedia, Wikimedia Foundation Inc., 16 Jan. 2017, en.wikipedia.org/wiki/File:3D_medical_animation_still_of_Type_One_Diabetes.jpg.

Header photograph taken by Miguel Choi.