Chia/Hemp seeds: Grinding into a powder destroys Nutritional properties?

I read that once seeds like Chia or Hemp are blitzed in the blender and turned to powder that they immediately begin to lose their nutritional properties?

I intend, so far, to attain Hemp in shelled format and blitz them myself i.e. turning them into powder, for my Green Smoothie diet. But now I am thinking about it, should I do this every day or can I do a weeks worth in a single batch and just keep it in the fridge?

How does Hemp powder settle in a fridge like condition if I wish to spoon it out?