It might.  It may also depend on what problem you have: prostatitis or bph
If you have prostatitis, abstinence may contribute to congestion which may
make the prostatitis worse.  I have read that too much sexual activity can
also make prostatitis worse.   From my own experience, regular ejaculation
is important to prostate health.  The definition of regular varies from man
to man. Every prostate is different.   I have no idea how sexual activity
affects bph.
Please be advised that I am not a doctor. I am speaking only from my own
experience and what I have read.
Phil

Doctor told me - and this isn't a joke - that I needed to have sex at least
once a week or "take things into your own hands" no joking!

I don't think he realised the pun.

I also don't think he realised that while option 2 is available like
McDonalds, most of the day, option 1 at near 50 is like being in a hospital
waiting room while having no medical insurance - you get attended to when
the other side is ready! :)

Scientific:  the prostate has the poorest circulation of organs.   You need
to do all you can to flush it with blood.   Getting horny helps.

Philosophical:  Hell.....don't hold back.  Blast away.   You might get run
over by a bus or train tomorrow and BPH will be the least of your problems!

Either approach:  why hang back?!!   Best of "outcomes" to you.

with BPH. I would be more concerned if I was suffering from
Erectile Dysfunction. so go with the flow.