I don’t think I’d take the paper itself seriously. Melatonin Research doesn’t seem to be a real journal and the paper looks very unprofessional. One of the paper’s authors is a lighting engineer who I think is trying to get people to use indoor lighting with more NIR, while the other seems to be a late-career melatonin guy who probably did some good research at some point. This isn’t to say that we should dismiss things unless they’re written by Credentialed Scientists® in a Serious Journal® and formatted in The Right Way®. But peer review does provide some protection from nonsense and we should be cautious about stuff that’s trying to look like it’s part of the academic peer-review system when it’s not.
As for the content, I’m not able to say much about the biology. I didn’t notice anything while skimming it that I know to be wrong, but I know very little biology, so that’s not surprising.
The optics is suspect. I’m pretty dubious about the thing with a “light guide” and the idea that the structure of a persons head/brain is supposed to distribute NIR in some way. I almost dismissed the stuff about NIR and the brain out of hand, but it turns out a human skull/scalp can diffusely transmit something like a few percent 830nm light, at least according to this paper with a simple but reasonably compelling experiment.
I’ll admit that paper does leave me wondering if longer wavelengths do matter somehow. It looks like a person standing in sunlight or next to a campfire probably does get some non-negligible NIR illumination through a substantial portion of their body. But I wouldn’t take that paper as strong evidence for or against much of anything.
Interesting, thanks for sharing.
I don’t think I’d take the paper itself seriously. Melatonin Research doesn’t seem to be a real journal and the paper looks very unprofessional. One of the paper’s authors is a lighting engineer who I think is trying to get people to use indoor lighting with more NIR, while the other seems to be a late-career melatonin guy who probably did some good research at some point. This isn’t to say that we should dismiss things unless they’re written by Credentialed Scientists® in a Serious Journal® and formatted in The Right Way®. But peer review does provide some protection from nonsense and we should be cautious about stuff that’s trying to look like it’s part of the academic peer-review system when it’s not.
As for the content, I’m not able to say much about the biology. I didn’t notice anything while skimming it that I know to be wrong, but I know very little biology, so that’s not surprising.
The optics is suspect. I’m pretty dubious about the thing with a “light guide” and the idea that the structure of a persons head/brain is supposed to distribute NIR in some way. I almost dismissed the stuff about NIR and the brain out of hand, but it turns out a human skull/scalp can diffusely transmit something like a few percent 830nm light, at least according to this paper with a simple but reasonably compelling experiment.
I’ll admit that paper does leave me wondering if longer wavelengths do matter somehow. It looks like a person standing in sunlight or next to a campfire probably does get some non-negligible NIR illumination through a substantial portion of their body. But I wouldn’t take that paper as strong evidence for or against much of anything.
Thanks for taking the time to read.
Here’s a 4 time board certified MD’s primer on light that mentions the paper (and related research):
Other highlights:
Sun exposure decreases all cause mortality, including from melanoma
Sun exposure has beneficial effect on brain volume in multiple sclerosis, independent of consequent vit D