Hmm..I've never thought about it, I also put kale into my smoothies and it makes me feel brilliant. I think that also raw kale has rich minerals and nutrients that are good for our body.. as long as we chew our smoothies well, I think it should not be a problem :)
Yes, kale is rich in minerals and nutrients, but for me, it is hard to digest. I definitely feel it every time I've eaten it, even in smoothies, and it is unpleasant, so I've stopped eating it. If you don't have a problem with it, I say go for it. I use baby spinach instead. also good for you, but goes down much easier.
Eating lots of kale and spinach and other dark things with oxalates can put you at risk for a calcium deficiency. The oxalic acid can inhibit absorption of calcium.
In general, eating lots of things with oxalic acid is not recommended. So maybe don't have the kale every day, but once or twice a week.
And cause problems like kidney stones and in some people gouty and other forms of arthritis:D
i stopped kale awhile ago, now i use baby romaine or baby spinach in my smoothies
For long term good results, we do not recommend kale and crucies. It is your choice if you want to eat them, but here is why:
For optimum digestion, avoid cruciferous veggies like broccoli and cauliflower, and root vegetables like carrots. Some of our members have had problems like diarrhea, gas, and bloating from these vegetables and or slowed digestion which makes it difficult to eat enough calories during the day.
A more easily digestible yet tasty cruci veggie might be baby spinach.
Better yet, try some romaine lettuce leaves in the smoothie.
Here is a list of what to eat and not to eat for optimum long term results: