"…a 60-year-old man who had a “history of studying nutrition in college” decided to try a health experiment: He would eliminate all chlorine from his diet…"

You can see already that this can easily go sideways. This guy is already exploring the nether regions of self-medication.

It would be ideal if LLMs recognized this and would not happily offer up bromine as a substitute for chlorine, but I suspect this guy would have greedily looked for other shady advice if LLMs had never existed.