While numerous studies over the years have alluded to the connection between lighting and health – claiming that certain “human centric” lighting configurations can enhance everything from mood to comfort, health, productivity, and more – experts say that the industry is far from being able to “prescribe” lighting for general population use and that the jury is still out on any positive or negative connection between science, light, and health.
Following, lightED reached out to lighting industry veterans James Benya and Deborah Burnett, principals of Davis, CA-based Benya Burnett Consultancy (www.benyaburnett.com), as well as Cory Schneider, CEO of Phoenix, AZ-based lighting distributor Lighting Unlimited (http://lu-az.com/), for their perspectives on the status of current lighting and health claims and whether these are driving factors behind today’s investments in energy-efficient LED lighting upgrades.
lightED: How do you respond to the numerous studies conducted over the years which conclude that lighting can enhance mood, comfort, health, productivity, or other elements of human behavior?
Burnett: What we do know is that a lot of “experiments” have been conducted in various settings and changes in both biology and behavior have been observed. But these aren’t conclusive, and our industry isn’t yet ready to provide recommended practice guidelines for specifying lighting systems for which we can promise a benefit. We’ve seen lighting manufacturer claims that promise to enable users to eliminate their medications for cognitive impairment and cure depression all by shifting the color of their indoor light based upon the color of the outside we think we see; however, the science of lighting isn’t as simple as color-changing lights!
Benya: It’s true. There’s active ongoing science published every day with a lot of manufacturing claims loosely based on the preliminary research, but the bottom line is that as of 2019, we simply don’t know enough to be able to “prescribe” light as simply as some manufacturers claim.
lightED: As a result, do you feel that the science on lighting and mood/health is somewhat like “the wild west?”
Benya: Absolutely. The industry is racing to offer color-tuning LEDs and promising outcomes that they shouldn’t be. Years ago, the FDA was put in place to regulate the pharmaceutical industry and there are parallels here; if we’re not careful about making unsubstantiated health claims, a lawsuit may someday raise the issue of lighting and health to Federal attention.
Schneider: I’m familiar with some of the claims being made — some of them are true and some of them aren’t. It’s a hard theory to quantify, but even a slight percentage increase in employee productivity can have as much or greater impact on a project’s ROI than the utilities; a 2013 World Green Building Council study found that better lighting improved productivity by 23% among the subjects studied. As far as health and mood go, only a few studies have scientifically demonstrated a positive connection, such as a case study from lighting researcher Dr. Mariana Figueiro, whose work involved a study measuring the impact of specially-programmed LED lighting for optimized circadian and sleep benefits for Alzheimer’s patients. Although many reports reference the benefit of the ‘Night Shift’ feature on Apple iPhones for affecting circadian rhythms, researchers are now questioning how much benefit this actually has on the ability to sleep at night or function optimally the next day. Other than a few of these types of ‘real-world’ investigations, I think that the science on this topic is only just emerging and that it’s definitely still the wild west.
lightED: With numerous recent studies indicating that LEDs operate on a wavelength that can disrupt our circadian rhythms, are LEDs good for our health?
Benya: LEDs are a light-generating technology and most conserve energy and save on costly energy bills. The most energy-efficient LEDs today utilize a white light which contains a larger percentage of the light provided by short wavelength blue light, which we perceive as white. While most lighting industry professionals understand that white light with a greater percentage of blue light isn’t good to use after the sun goes down, few understand the complex science behind the fact that human health, sleep, and other biological factors can be impacted by improperly-specified lighting systems.
Burnett: Today’s lighting specifications should consider the biologically-active wavelengths of white LED lights, which are comprised of all wavelengths energies, including short (blue) and long (red) visible radiant energies. These are known to biologically impact heart rate, blood pressure, pupil constriction, sleep, and many other factors. It’s not as simple as buying a “one size fits all” color-changing system – to specify and install LEDs correctly, one must understand the people who occupy the spaces we light, including their general age range, fitness level, and daily activities in addition to technical control aspects which include specific settings for the timing of the light color shifts, the intensity of the differing light levels, and of course the duration of any given light setting. Used improperly, LED lighting is a known endocrine disruptor and has the potential to overwhelm the circadian system, hormonal production, and diurnal neuroendocrine response. Science has even demonstrated specific bandwidths of LED white light which penetrate our skin and impact a number of genes, including genes P53 and P21, which contribute to melatonin production and timekeeping of the master biological clock; this, in turn, affects our overall health and even our tumor-protective response. Recent studies reveal that LEDs can especially impact hormonal-based cancers and completely undermine the power of medications like Tamoxifen, which is often used to treat hormone-receptor-positive breast cancer.
lightED: How would you recommend that lighting professionals and end users weigh these pros and cons (e.g., the energy savings/boost to sales, productivity, etc. versus any adversarial health effects of LEDs) when making a lighting investment?
Benya: While LEDs are indeed more efficient than any other light source, the most efficient LEDs produce the worst spectral issues because they operate in the blue spectrum. In terms of best practices, the higher the CRI of the light source, the better it is because it moves more of the blue energy to longer (red) wavelengths; a CRI of 90 or better helps mitigate health issues. In addition, you want to reduce the light level (via dimming) as well as the color temperature of your light sources at night, using lighting that’s no more than 2700K.
Burnett: In addition, residential consumers shouldn’t use ceiling or bright bath vanity lights after 8 PM because it’s been demonstrated that this type of overhead lighting can not only overwhelm our circadian rhythm, but can disrupt our entire endocrine system as well. I recommend the use of undercounter lighting, table lamps, and portable floor-mount uplighting cans complete with amber-colored LED bulbs. The bottom line is to keep all light below eye level and shining on the vertical surface via lighting that shines on walls, not lighting that comes down from the ceiling. At night, people should also try to mask the overly bright white light coming from computer screens and electronic devices while they sleep, as this light has now been shown to penetrate our eyelids and impact biology even when they’re closed. For industry members, we recommend that all lighting professionals invest in a spectrometer and specify the properties and spectral power distribution of light, not just the Kelvin temperature or CRI. To design a lighting system that ensures minimal or no biological impact, professionals need to keep all of the shorter wavelengths around 20% with an ideal of 12%, especially at night. And for both residential consumer and professional users alike, the best specifications include exposure to as much natural daylight (sunlight) as possible.
lightED: Do you feel that most end users are concerned about lighting and health at all, or do most lighting investment decisions today focus primarily on economic factors?
Schneider: I find that end users are generally unaware of the health/mood aspect when it comes to lighting upgrades — the majority of purchase decisions (95% or more) are based on economic factors. Our team isn’t actively selling lighting based on the health angle, but we do our best to sell higher-quality products based on their ability to improve the productivity of employees and the value of the space. I believe there’s a future in the lighting-health connection, but the marketplace and the science need to improve. Perhaps as more and more studies come out, people will start caring more and more about the health effects of lighting. Customers aren’t asking for it yet, but demand would seem to be inevitable and large in a saturated led market, as forecast by ResearchandMarkets.com in their recent “Human Centric Lighting Global Market Forecast 2018-2028.”
Benya: I agree. From my experience, end users don’t care very much about the lighting and health connection. Most purchase decisions today are about providing enough lighting for the task using the least amount of energy and the least expensive equipment they can get away with. But there are pockets of interest and some careful scientists working on this topic. There are a lot of good studies out there, but they’re far from conclusive; they’re careful to set expectations and manufacturers and overzealous specifiers should do the same.
Burnett: I observe human behavior and the look of sheer frustration on consumers’ faces confirms that the process of selecting LED bulbs and luminaires confuses them; they often feel that there are no reliable choices or even basic education on LED lighting options. Meanwhile, manufacturers are marketing their most energy-efficient (LED) products to building owners, who care mostly about energy savings with little interest in either the benefit or potential harm these sources are capable of delivering. In the end, I think that when researched and thoughtfully designed, one can create a perfect luminous environment which includes daylight and spectrally-curated electric LED lighting systems designed to optimize circadian and endocrine protection without delivering potential unintentional biological consequences.
Tagged with health, LED lighting, lightED