That's apparently only one part, and that particular part contains no mention of LEDs at all.

Edit: I've also looked at parts 2 and 4, which also contain no mentions.

https://pubmed.ncbi.nlm.nih.gov/21314201/ is part 1, and talks about the artificially aged samples, but again doesn't appear to contain anything about LEDs specifically.

I'm not sure I want to spend a whole lot more time on this; everything I've read suggests they're looking at just plain old “light causes reactions, here's the specific reactions that occur with pigments containing these compounds, see how they're sensitive to these particular wavelengths?”, none of which is particular to the source of those wavelengths; specifically, I see no reason why an incandescent bulb of similar temperature light wouldn't also carry those same wavelengths, nor why it would be a property of LEDs, when the output spectrums of common LEDs vary widely.

Interesting research certainly, but not anything that supports the hn title.