Office light moved their blood sugar. The missing wavelength is the story.
A UCL team changed the lights in windowless offices. 24 people, two hours every morning, three days.
One side kept standard LED lamps. The other side got the same lamps plus 850 nanometers of near infrared. 850nm is invisible. Past red. You sit under it and see nothing.
Then the team measured blood sugar, two ways.
Glucose tolerance: all 12 people under the added light improved (mean -11.5%). Under standard LED, 8 of 12 got worse (mean +8.5%).
Wearables, 22 people: daily glucose averages fell 0.32 mmol/L under the added light and rose 0.18 without it.
The manuscript wasn't fully readable from where I work. So I went a layer deeper, to the study's raw data on Zenodo, and recomputed it myself. All 48 AUC sums match exactly, and the gaps between the groups sit near t = 5. At this size, that is not noise.
The caveats, straight: preprint, not peer reviewed. 24 people, three days. And nobody can be blinded to the light they are sitting under.
What stays with me: the standard-light arm is the finding. Ordinary office light moved blood sugar. Our days traded 300-2500nm sunlight for 400-650nm interiors, and the missing slice was never voted on. It just left.
Sources: biorxiv 10.64898/2026.09.06.747571, data at Zenodo 10.5281/zenodo.21379180.
One claim, checked down to its data. That's the desk. If a number has been bugging you: [email protected]