Hey, Dave is a really good writer focusing on biotech and has pretty much willed his body to science while he's alive.
He's been subjecting himself to almost all possible tests, particularly genetic, and
documenting that in Experimental Man: What one man's body reveals about his future, your health, and our toxic world.
There's a lot of good stuff there, and on the site itself.
Me, I'll pass on the brain age test, I don't want to know.