In this episode, Anna explores a newly published study investigating the relationship between light exposure patterns and symptom severity in people living with ME/CFS.
Rather than focusing on light as a treatment, the research highlights the potential role of circadian rhythm and how consistent daytime light, alongside reduced evening light exposure, may be associated with better sleep, lower fatigue and improved quality of life.
Anna explains why light is much more than something that helps us see—it acts as one of the body’s most important biological signals, helping to regulate sleep, hormones, nervous system function and energy metabolism. She also discusses the limitations of the research, why these findings should be interpreted with caution, and how they fit within a whole-person, systems biology approach to ME/CFS.
If you’ve ever wondered whether your environment can influence your physiology, this episode offers a balanced, science-led discussion of what this emerging research may—and may not—tell us.
In this episode you’ll learn:
- Why light plays a vital role in regulating circadian rhythm and overall physiology.
- What this new ME/CFS study investigated and what the researchers found.
- Why the timing and consistency of light exposure may matter more than simply spending more time outdoors.
- The limitations of the current evidence and why association does not equal causation.
- Anna’s clinical perspective on supporting circadian health as one part of a comprehensive, individualised approach to ME/CFS recovery.
Useful Links
Research Article: https://pubmed.ncbi.nlm.nih.gov/42399727/
Take the Chronic Fatigue Quiz: https://app.annamarsh.co.uk/quiz-page
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Website: https://annamarsh.co.uk/








