Dandruff or scalp irritation? Try BLOO.
If sugar causes wrinkles, how do you explain this? Not a single forehead wrinkle. That expression should produce wrinkles. Incredible skin. He's doing something right. (47-48? and Paul is 47 here)
(And the energy of a 10 year old with adhd after 15 years of fruit, honey and sugar)
FYI, the thread has been updated to clarify that sun exposure is probably not the answer.
sounding very catty
Sounding catty should mean meowing or hissing, right? idk
Update:
Bad news cat lovers, anger towards cats appears to be growing:
catty (adj.)
1886, "devious and spiteful," from cat (n.) + -y (2). Slightly earlier in this sense was cattish. The meaning "pertaining to cats" is from 1902. Related: Cattily; cattiness.
"devious and spiteful," 
Someone should fix this. Subconsciously you encourage cat abuse. I'm not even kidding.
@Serotoninskeptic It's possible. Maybe he just picked a very bad mixture that even includes sugar as Johann said.
The rapid change has me thinking there must me more to it.
I need to look for some samples of white surfers living in Costa Rica. That is a genetic mismatch. He is not well adapted that sun intensity. But was he not already surfing? He just changed so fast. It's hard for me to get my head around it.