Short summary: 25 years ago, if you had asked a researcher what is the most important antioxidant in the human body, they would have answered vitamin C or maybe vitamin E. 12 years ago, they probably would have answered glutathione. Nowadays many researchers think the most important antioxidant is melatonin in the mitochondria. melatonin cannot get into the mitochondria, but serotonin can, and the mitochondria contains enzymes to convert that serotonin to melatonin -- and certain frequencies of light in the red and the near infrared greatly increase the rate of mitochondrial melatonin production.

From the article:

> ACKNOWLEDGEMENT

> No external funding sources were used in this review.

That's also strange. It's not a smoking gun, but everyone gets some funding fro somewhere.