Story summary
In recent months, there has been growing concern among health advocates about the potential negative effects of LED light bulbs on human health. John Lincoln, co-founder of the charity LightAware, reports an increase in people contacting him regarding issues related to flickering LEDs and their impact on migraines. These concerns are now prevalent across social media platforms where influencers advocate for switching back to traditional incandescent bulbs, citing numerous health benefits from doing so.
The debate centers around claims that LED lights can cause or exacerbate conditions such as headaches, anxiety, eye strain, disrupted sleep patterns, brain fog, hormone imbalances, and feelings of exhaustion. Emerging scientific research supports some of these assertions, suggesting a possible link between LED lighting and negative health outcomes including diabetes and certain types of cancer.
In 2009, the EU initiated a directive aimed at reducing carbon emissions by phasing out incandescent bulbs in favor of more energy-efficient alternatives like LEDs. However, critics argue that this switch could be detrimental to public health due to the side effects associated with prolonged exposure to LED lights.
Written for “LED Bulb Health Concerns” on 2026-10-06,
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Health influencers have finally moved on from blitzing green juices and performing squats.
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influencers → publish → squats
Across social media, the posts receiving millions of views are now far more likely to show an LED light bulb being unscrewed and switched for an old-fashioned incandescent version.
‘I just received my box of flicker-free circadian-friendly light bulbs,’ enthuses one.
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one → receive → bulbs
Others suggest swapping ‘government bulbs’ for ‘freedom bulbs’… ‘unless you want the constant headaches, anxiety, eye strain, disrupted sleep, brain fog, hormone disruption, and that wired but exhausted feeling’.
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you → swap → headaches
LEDs (light-emitting diodes) in the home and at work are being blamed for everything from diabetes to certain cancers.
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LEDs → emit → cancers
It sounds far-fetched but emerging scientific evidence suggests there may be an element of truth to all this.
uncertain
evidence → sound → this
Incandescent bulbs, developed in the 1800s, produce light when an electric current heats a thin tungsten filament, which heats up and glows – but this wastes 90 per cent of the energy used through heat.
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this → develop → heat
So in 2009, under an EU directive to cut carbon emissions and save energy, the government began phasing out traditional incandescent bulbs, with a full ban from 2016 (although, if you can find them it’s not illegal to buy or use them).
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it → cut → them
Slowly homes, hospitals, schools and work places made the switch to LEDs.
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homes → make → LEDs
These bulbs require far less power (90 per cent less electricity than incandescents) and tend to last longer while costing roughly the same per bulb.
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bulbs → require → bulb
Rachel Mitchell, 48, had no health issues until in 2021 – when she changed her light bulbs at home to LEDs, got a new LED computer monitor and her husband brought home an LED TV
Left: An LED light bulb, which produces light through a process called electroluminescence.
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which → have → process
Right: An incandescent bulb, which produces light when an electric current heats a thin tungsten filament
They
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current → produce → filament
mainly emit short-wavelength blue light, ranging from 400 to 500 nanometres (nm), which tends to be a harsher, brighter light.
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which → emit → nanometres
Studies agree this increases alertness, and can delay sleep and affect blood-sugar levels.
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this → agree → levels
Meanwhile the high-energy, inefficient incandescents lauded online are a source of red and infrared light – with red emitting long wavelengths of light ranging 600-700mm, and infrared 700-2,500nm – which we also get naturally from sunlight.
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we → laud → sunlight
This is the key to its acknowledged benefits.
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This → acknowledge → benefits
‘An incandescent light bulb roughly puts out a similar spectrum of light as the sun, although you don’t see most of it,’ explains Glen Jeffery, a professor of neuroscience at University College London.
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Jeffery → put → London
‘An LED light only puts out visible light – but no deep red or infrared which we need to keep our cells functioning effectively.’
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we → put → cells
He adds: ‘The problem is we spend over 90 per cent of our time in the built environment.
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we → add → environment
Most people have LEDs in their homes and workplaces – and they are completely overpowered by the influence of them.
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they → have → them
‘Bear in mind windows filter out infrared light, too.
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windows → bear → light
As a result, we are receiving a lot less long-wave light than our ancestors.
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we → receive → ancestors
‘The effect of this on our health is cumulative over time,’ he adds.
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he → add → time
‘We can keep the LEDs for generating light economically in places but we need a different light form for physiological health.’
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we → keep → health
Science is only beginning to reveal just how vital this long-wavelength light is for health, but studies have linked low exposure to type 2 diabetes, anxiety, skin ageing, obesity and cancer.
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studies → begin → diabetes
How LED light affects us precisely is also still unclear.
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affects → affect → us
Professor Jeffery points to evidence that suggests it affects the mitochondria – the ‘batteries’ in cells that provide energy.
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that → point → energy
This potentially has knock-on effects across the board.
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This → have → board
For instance, research has shown that LED lighting can affect how we metabolise sugar.
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we → show → sugar
In a 2024 study in the Journal of Biophotonics, Professor Jeffery and his team showed that a 15-minute burst of red light significantly reduced participants’ blood-sugar levels after a large intake of glucose.
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burst → show → glucose
In another study by Maastricht University in the Netherlands, published last December, 13 people with type 2 diabetes spent four days working in an LED-powered office, then another four days working under natural light in the same location.
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people → publish → location
‘The biology is very strong,’ says Professor Jeffery.
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Jeffery → say → ?
‘The absence of infrared light in an LED is definitely associated with pre-diabetic states and a general decline in mitochondrial function – which translates as a decline in metabolic health.
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which → associate → health
Could LEDs also affect our body clock?
uncertain
LEDs → affect → clock
Russell Foster, a professor of circadian neuroscience at the University of Oxford, says it’s complicated, but essentially blue light in the evening in a domestic setting will increase alertness and, if seen long enough, will shift the clock.
But it’s not as simple as blue light is ‘bad’ and red is ‘good’.
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red → say → clock
‘LEDs have an important role in producing bright light under certain circumstances – for example, in the working environment when you need to promote alertness,’ says Professor Foster.
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Foster → have → alertness
‘Where you need to be a bit more careful is when using bright light for a long duration in the evenings.’
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need → need → evenings
Professor Foster uses a combination of LEDs in his office in the day and a ‘lovely old-fashioned lamp’ with a LED red-enriched light bulb in the evening.
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Foster → use → evening
While many of us may not notice much of a difference from one light bulb to the next, for others it can be stark.
uncertain
it → notice → others
Rachel Mitchell, 48, a former management consultant, had no health issues until in 2021 – when she changed her light bulbs at home to LEDs, got a new LED computer monitor and her husband brought home a huge new LED TV.
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husband → have → TV
‘Within a fortnight, I started getting a pressure sensation behind my eyes – like a vice around my head,’ says Rachel, who lives in Cheltenham.
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who → start → Cheltenham
…and 27 more, not listed.
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