"Rupert (W.Yorkshire)" replied:

I think the theory is that the newsprint is made of chemicals which may be
nasty. ---
As a staff member on a daily newspaper for most of my working life, I came
into close ( very close and messy at times) contact with printing ink every
day. The ink didn't appear to harm me inwardly, but might well have had a
lot to do with me becoming folically challenged by the time I was 55.

MikeCT