It’s love your lungs week in the UK
Although the desperate memories of Covid-19 may have lost their brittle edge, I for one will never take my lungs for granted again.
Respiratory conditions are the second-leading cause of death worldwide – The top 10 causes of death.
And, while a growing number of younger people are suffering from asthma and other respiratory conditions, by the time we’re 65, one in ten of us will be diagnosed with a condition that affects our lungs – one of the leading causes of hospitalisation and a significant cost to the NHS – Incidence and prevalence of asthma, chronic obstructive pulmonary disease and interstitial lung disease between 2004 and 2023: harmonised analyses of longitudinal cohorts across England, Wales, South-East Scotland and Northern Ireland.
Asthma and COPD (Chronic Pulmonary Obstruction Disease) are the most common, both characterised by inflammation of the airways and lung, leading to shortness of breath.
Interestingly, a number of the medications used to manage the symptoms of dementia can make these symptoms worse because they affect the critical interplay of muscles and neural pathways that make it possible to breathe, speak and swallow through the same physical pathway –
So what’s that got to do with lights?
While asthma symptoms follow a clear temporal pattern – worse in the evening than earlier in the day – The Circadian Rhythm of Asthma Immune Metabolism, perhaps unsurprising given the inflammatory dimension of the condition, there’s growing evidence that disruptions to the body clock may increase risk of developing the condition in children – Circadian rhythms and asthma: exploring the impact of circadian clock proteins on childhood asthma management.
That inflammatory dimension may offer another link with light, with promising results from mouse models that show near infrared laser treatment boosts the bodies own cellular response – Near-Infrared Laser Photobiomodulation Reduces Pro-Inflammatory Cytokines in an In Vitro Model of Bronchopulmonary Dysplasia: A Preliminary Report.
Perhaps because of the strong circadian component, asthma treatments are among the first to have demonstrated the effectiveness of a ‘chronotherapeutic’ approach, with optimised timing for inhaler significantly more effective at managing symptoms as random timing with no additional incidents, suggesting that this strategy effectively dampens the inflammatory response rather than simply delaying it – The impact of dosage timing for inhaled corticosteroids in asthma: a randomised three-way crossover trial. These insights are key to leveraging machine learning models to develop personalised framework for treatment – Study of AI-Enabled Chronotherapy Including Optimizing Medical Treatment Cycles Via Real-Time Circadian Biometrics.
Interestingly, there are promising results in early trials that use melatonin as an alternative than the traditional steroid approach, potentially targeting the cause rather than the symptoms – Melatonin: a promising therapy to combat type 2 airway inflammation via MT1-Sirt1 pathway.
Time to get outside and take a deep breath and appreciate that amazing machine that keeps the show on the road.
The hue-heat response – all in the mind?
Here in the UK, we’ve been complaining about the heat – of course we’ll be banging on about the cold and wet as soon as schools break up for the summer.
I wondered if looking at the lights might help
This is one situation where LED’s have the edge over classic incandescent lightbulbs, as they give off little or no heat (the incandescent does what it says on the tin – it glows, kicking off around 80% heat for just 20% light).
A classic hypothesis, known as the ‘hue heat’ effect, suggests that we tend to feel warmer in spaces that look cosy – and cooler in those that appear fresh and cool – Effect of illumination on perceived temperature.
The jury is still out on exactly how this connection might work – there are so many variables involved in psychophysical experiments – ethnic background and cultural context, age and gender to name a few.
But this recent paper caught my eye, suggesting that time of day is another variable that we need to take into account, as there is a strong time of day component in thermal regulation, with your temperature lowest first thing in the morning with a steady rise over the course of the day.
This team found that bright light exposure in the morning effectively improved objective and subjective perception of thermal comfort under slightly warm conditions, effectively suppressing that natural rise. The same light levels at midday, or dim light at any time of day didn’t make a difference, Equally, under slightly cool conditions, changing the lights didn’t seem to affect perceived temperature or comfort in a meaningful way.
The paper concludes ‘these findings underscore the fundamental role of circadian physiology in thermal comfort and suggest that strategically timed light and thermal exposure can optimize comfort by aligning ambient conditions with the body’s internal rhythms – Acute effect of light and time of day on thermal physiology, perception, and behavior.
I for one do tend to feel that spaces that look fresh and cool tend to trigger that expectation, but I know it’s all in the mind.
The body clock on the other hand isn’t fooled.
Another reason to get outside before the sun gets too high in the sky.