How the right light can promote good health

By: Allison Zisko, Editor-In-Chief, Designers Today

I was thumbing through our most recent periodicals and ran across this article in Designers Today magazine about lighting and how it can promote good health. As we analyze the needs of our clients, may it be in a healthcare setting or correctional facility, we are always seeking out lighting designs that improve the health and well-being of those who inhabit the spaces we design. Bringing the natural light of the outdoors inside has proven to improve productivity and worker satisfaction for most spaces. Two important factors to a well-balanced and healthy environment. Read more from Allison Zisko, from Designers Today magazine, about how lighting plays such a critical role in good health.

What if you could cure disease and promote good health with the flick of a light switch? Although it almost seems too good to be true, recent research into healthy lighting reveals many ways that designers can incorporate different types of light into a room to counteract conditions ranging from ADHD to migraines, while also promoting healing and good sleep.

Unnatural light at inappropriate times of the day can have an adverse effect on health and well-being, according to Jeffrey Dross, a 47-year lighting industry veteran who spoke at Designers Today’s recent Designers Experience event.

Dross walked his virtual audience through an explanation of how natural light changes in color from sunrise to sunset: it starts out white in the early morning, becomes very blue by midday and then gradually turns reddish-orange in the evening before darkness falls. Human biological systems, such as our circadian rhythms, were designed to run in sync with the natural progression of light from day to night. Blue light is associated with alertness and activity, while reddish light is calm and soothing.

The advancement of artificial light, however, has messed with nature’s plan. Although early forms of artificial light, beginning with fire and progressing to incandescent light bulbs, gave off reddish-orange hues, the introduction of fluorescent lighting (which was developed during World War II) and solid-state lighting (or LED, which first came on the scene in 2002) has raised health concerns (and which is why there has been a proliferation of stories about the hazards of scrolling through a smartphone in bed late at night.)

In a separate interview, Dross recounted the progression of natural light throughout the day. “This is the light our bodies were engineered to receive,” he said. “When we diverge from that, problems can ensue.”

Blue light at night is detrimental in part because it suppresses the secretion of the hormone melatonin, which not only helps modulate circadian rhythms but is also believed, according to the most recent studies, to be an anti-cancer hormone that blocks the fatty acids and glucose required for cancer cell growth.

Can “good light” limit cancer growth? According to Dross, the research is ongoing and not definitive, “but tells us to pay attention to the amount of color and light” in a room.

Flicker, which is a fluctuation of light, can also cause adverse health effects for people who suffer from photosensitive epilepsy (20% of epileptics), migraines (10% of sufferers), those with photophobia (extreme sensitivity to light) or autism, and, to a lesser extent, those who suffer from Ménière’s Disease or are HIV-positive, Dross said.

Interior designers can limit LED flicker, advised Dross, by avoiding low-priced and AC LED (an LED that operates on AC voltage), specifying integrated LED lighting rather than LED replacement lamps, and being careful with dimmable LEDs where they are not needed.

Dross also recommended that designers avoid excessive bright light and install warmer light (in a range of 2700 to 3000 Kelvin, but no higher than 3000 K) where possible.

Migraines are the second most common type of headache and affect 10% of the world population — women are three time more likely than men to suffer from them. Doctors and scientists believe migraines can be triggered by light, and that blue light triggers the strongest pain response, Dross said. He noted a 2017 Harvard University Medical School study exploring the positive effects of a very narrow wavelength of green light (not a green-tinted light). A company called Allay Lamp has capitalized on this research with the Green Light Allay Lamp which it claims calms the brain by quieting hyperactive neurons. It was developed by the Harvard Medical School neuroscientist with a study at Beth Israel Deaconess Medical Center (Rami Burstein, et al) published by the Oxford University Press.

For people suffering from ADHD, autism or sensory processing disorder, Dross recommended using less reflective light in a room (paying attention to shadows), soft lighting (from an upward source, such as a torchiere) that is indirect with no glare, and higher frequency light sources with no flicker.

Aging eyes perceive blue light as brighter than white light, according to Dross, but he did not recommend changing the color of light in a room, but to add more task and portable lighting, such as lamps, to a workspace.

Additional resources:

For more information on how lighting can affect our health, Jeffrey Dross recommends the following resources:

• The Light and Health Research Center is a wonderful resource of information about lighting and health. It recently moved to the Icahn School of Medicine at Mount Sinai in New York.
• For young people: “Short Wavelength Light Enhancing Cortisol Awakening Response in Sleep-Restricted Adolescents,” Rensselaer Polytechnic Institute – Lighting Research Center
• More reading: “Effects of White Light Devoid of ‘Cyan’ Spectrum on Melatonin Suppression Over 1-Hour Exposure Duration,” Journal of Biological Rhythms, March 1, 2019, Rensselaer Polytechnic Institute – Lighting Research Center

This article first appeared in the July/August 2022 issue of Designers Today.