thoughts on the smoothie

Hi everyone,
It seems it's been a little while since this subject has come up. I
have been drinking a smoothie nearly each morning for a month or two
now and still love them but decided to look into how healthy they
actually were. Below are typical ingredients for my ~750mL serving.
This is enough to last me 4-5 hours before eating again. I'd like to
hear any thoughts that come to mind.

50 mL water
125 g fat-free yogurt
35 g spinach
1/2 cup blackberry, blueberry, raspberry frozen mix
1 cup chopped frozen fruit (peaches, strawberries, pineapple, honeydew
melon, red seedless grapes)
one banana
2-3 tbsp. ground flax
1 tbsp hemp hearts
1 tbsp Salba
1 tbsp olive oil

Sometimes I add one of the following for a change:
a piece of ginger (unpeeled)
half clove garlic
avocado (peeled)
apple (no core, skin on)

I've lately realized too much spinach is not a good thing because it
is high in oxalic acid which can cause kidney stones. I also saw
berries listed as being high in oxalic acid. I figured there would be
others interested to hear of the oxalic acid issue and others still
who could recommend what amounts are okay.

cheers,
chris
.