Yes — plum flesh is safe and well liked, but the pit must be removed: stone-fruit pits contain cyanogenic compounds.
Keeper's notePit first, always. Fresh plum over prunes — the dried form concentrates the sugar into candy territory.
What to watch out for with plums
Plums are a stone fruit, like cherries and peaches. The soft flesh is vitamin-rich and harmless, but the kernel inside the pit contains amygdalin, which releases cyanide when crushed and digested. Dried plums (prunes) are also very high in sugar.
How to serve it
Remove the pit before offering; halve for small species.
Wash well or peel — stone fruits carry surface pesticide residue.
Prunes only rarely, in tiny amounts, for their sugar.