Healthier lighting options for homes

By Chris Henderson

As a health practitioner, I have always been interested in applying the latest research and recommendations around Diet, supplements and stress reduction strategies to myself and my clients. What I didn’t realise was that I had missed a massive piece of the puzzle: we are bio-electrical beings tuned to environmental signals that control our physiology and chemistry. One of the most important signals is light. In my modern office environment, fatigue, headaches and eyestrain were common symptoms. With my research hat on, I dove into why this environment could affect my health to such a degree. My previous good vision had disappeared, and I needed prescription glasses within six months of working in an environment full of artificial blue light and wifi. Upon further study, I started to understand the incongruence these technologies were having on my health – light was kicking my butt literally! 

Light is a natural electromagnetic frequency (EMF) that humans have spent thousands of years exposed to. Natural light is balanced in wavelength and frequencies. We are tuned to the visible and invisible colours and frequencies of sunlight via photo-receptors in our eyes and skin. However, during the last hundred years, this has been significantly altered due to the advent of the electrical power grid, radio, telecommunications, and, more recently, wifi and energy-efficient LED lighting. Especially the surge of ‘smart technology’ is mostly incongruent with critical biological functions that support human health. 

Have you ever wondered how something as simple and commonplace as the light surrounding us can influence our body chemistry and state of mind? The two key hormones relevant to light exposure are serotonin and melatonin. Serotonin is popularly thought to be a contributor to feelings of well-being and happiness, while melatonin regulates your sleep-wake cycle and cellular repair and renewal process while we sleep. For many people, feeling good and sleeping well are distant memories they would like to revive! Ideally, we should have high levels of serotonin during the day and melatonin at night. But with melatonin production being particularly sensitive to the light we receive, the type of light we are exposed to becomes critical. 

Sunlight in the early morning activates a series of hormonal reactions in the pituitary, thyroid and adrenal glands, which then promote the diverse actions of the body and health. These actions are what allow us to feel alert, focused and attentive. 

On the flip side of this, the dominant blue light found in modern LED lighting, phone screens, computer monitors and TVs that we all use inhibits melatonin production, and sleep becomes harder to find. 

It’s incredible to think that in our busy modern world, we spend most of our time living under artificial lighting without paying attention to the consequences for our bodies and mind. Whereas people are concerned about organic food, pure water, and clean air, the element by which our very life came into existence – light – is often forgotten. For example, what is not commonly known is that we need a balanced light spectrum to help our body convert the electrons we take in from food to make cellular energy (ATP).

In the early 1950s, Dr John Ott made a name for himself with full spectrum light when he devised a way to capture the growth of plants in slow motion for a Walt Disney production that had to be filmed indoors. Initially, the plants failed to produce blossoms and even died because of insufficient daylight exposure; this eventually led to the creation of a new lighting range specifically developed for this purpose. Modern LED and CFL lighting may be energy efficient and fits the eco-friendly profile; however, the short wavelengths of artificial light have many biological consequences. The oxidative stress induced by blue light affects the retina, causes headaches and eye strain, and can eventually lead to macular degeneration and cataracts. 

Blue and green light dominant cool and warm white LED lighting pose other significant issues that most people aren’t aware of: the ‘flicker’ effect and ‘colour temperature’. Conventional fluorescent and LED light bulbs fluctuate in brightness many times per second because the alternating current is not constant. This results in the “flicker” effect, which isn’t consciously noticeable. However, ‘flicker’ can still be picked up by the brain, irritate the nervous system, and induce other significant symptoms: including eye strain, double vision, headaches, migraines, stress, poor concentration, reduced visual task performance, fatigue and repetitive behaviour in autistic people.

color temperature exampleLighting higher on the colour temperature scale, such as ‘cool white’ LEDs, emit significant amounts of artificial blue light, which signals the brain that it’s daytime and interferes with your circadian rhythm. It does this by stimulating ‘melanopsin’, a photosensitive pigment in the retina that suppresses melatonin production. 

For these reasons, many researchers and lighting industry bodies are looking more critically at the quality of the lighting available to the trade and consumer market. An article in the LED Professional ‘The global information hub for Lighting Technologies and Design’ stated, “With the evolution of LED lighting, one topic has come more and more in the focus of the lighting industry: Human Centric Lighting (HCL). While HCL is not clearly defined, a common understanding is that this is light and lighting that supports the health and well-being of humans. Some new proposals are going beyond the approach of providing just visible light of inadequate quality, but also to providing invisible radiation, UV and/or near-infrared, that support health and wellbeing. Some research and the evolution of humans show clear evidence for positive effects of this kind of illumination.”

To add weight to this argument, research done by Prof. Abraham Haim, with scientists from Italy and the US, published findings on the subject in the Journal of Environmental Management. Their study was the first to examine differences in melatonin suppression in various types of light bulbs, primarily those used for outdoor illumination, such as streetlights, road lighting and mall lighting. The University of Haifa researcher declared in 2008 that exposure to light at night is the most potent factor in breast cancer besides genetic defects. Other studies have implicated it in prostate cancer and the development of nearsightedness in children, eyestrain, headaches and sleep disorders.

Further conclusions arose from those studies: “Unless legislation is updated soon, with the current trend toward sources as white LEDs, which emit a huge amount of blue light, we will enter a period of elevated negative effects of light at night on human health and environment. Lamp manufacturers cannot claim that they don’t know about the consequences of artificial light at night,” says Dr. Fabio Falchi of ISTIL.

“As a first step in Israel, for example, the Standards Institution of Israel should obligate bulb importers to state clearly on their packaging what wavelengths are produced by each bulb. If wavelength indeed influences melatonin production, this is information that needs to be brought to the public’s attention, so consumers can decide whether to buy this lighting or not,” Professor Haim added. 

Clearly, human-centric lighting should be favoured to support health and well-being. When considering the building and design of sustainable homes, communal buildings or tiny homes, many details are consciously planned around materials and layout that are set to fulfil specific eco-friendly principles for environmental and health reasons. Shouldn’t we also include health-friendly lighting choices when building our homes?

As a health practitioner and consultant, I work with companies that have reverse-engineered modern LED lighting problems and created solutions that are much healthier for human use. These include removing harmful blue light frequencies, removing the flicker effect as well as reducing the amount of ‘dirty electricity the fitting is putting back onto the power supply. Research and development of a full-spectrum light for daytime use that can be phased into amber and red at night are also in the works. We see this as a game-changer in supporting healthier indoor lighting. 

For more information on health-optimised lighting solutions, contact Chris Henderson at

And don’t forget to check our products for circadian-friendly lighting options.

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