The stems are by far the most beneficial. And this is why:

Strengthens the nerves and thus has a calming effect

Very hydrating, so good for thirst

Very useful for your kidneys and prevent the formation of kidney stones

They are diuretic, meaning you have to pee a lot... and when I say a lot, it is a lot haha

They are cleaning your blood

Very effective against rheumatism, arthritis and atherosclerosis

Have the effect of relieving pain (e.g instead of swallowing a handful of aspirin, eat a cherry)

Lower your cholesterol

Help weight-loss because it simplifies getting rid of water retentions

Your digestion gets easier (You may get a gippy tummy at first, but this will be okay after a short period of time, your body needs to get used to it, so don't worry)

They are very beneficial for your liver too

Cherry stems help to open your respiratory and you can expectorate easier when you caught a cough or cold.