It's very healthy, I like to prepare a lemon, ginger honey tonic and drink it with luke warm water in the morning, it can make your day
Discussion
Dieting with lemon juice was trendy some years ago. Iv seen someone totally eviscerate her stomachli lining with those acids. Life is all about balance.
Your friend more than likely had other contributing factors. Everyone has their N=1 when it comes to health. This is one of the many reasons centralized medicine is a sham. The same shoe doesn’t fit every foot….wish you and your friend the best.