The Claim
The melanopic to photopic (M:P) ratio differs significantly among various lamp types, with cool white LEDs exhibiting the highest median M:P ratio (~0.69), leading to greater circadian system stimulation relative to visual brightness, whereas incandescent lamps show the lowest median ratio (~0.34), suggesting they are more circadian-friendly for use in the evening.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Cool white LED lights might mess with your sleep more than old-style light bulbs because they affect your body's internal clock more, even if they look just as bright. Old incandescent bulbs are gentler on your circadian rhythm at night.
See the scientific wording
The melanopic to photopic (M:P) ratio varies significantly across lamp types, with cool white LEDs having the highest ratio (median ~0.69), indicating a disproportionate stimulation of the circadian system relative to visual brightness, while incandescent lamps have the lowest ratio (~0.34), making them more circadian-friendly for evening use.
What the research says
1 studyStudy: Home lighting, blue-light filtering, and their effects on melatonin suppression
The study shows that cool white LED and fluorescent lights reduce melatonin more than warm or incandescent lights, which means they affect sleep more—just like the claim says.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.