So, as for the smoothies I have been making, I have tried to balance between green, fruit, yogurt, and peanut butter based smoothies. I am beginning a weight training regimen and I'm supposed to get 100 grams of protein a day, so it is important to incorporate protein into my smoothies when possible. I have to admit, I was really nervous for my first green smoothie. I wanted to like it, but, who would like ground up spinach, kale, or Swiss chard in their drink? I thought I would trust the 4-5 star recipes first and found that so far they have all been great! The fruit hides the greens flavor really well. If you tasted the spinach, or greens, in your smoothie before you should try some of the recipes I have. They are on my pinterest page. http://pinterest.com/menkeer/smoothies-i-like/ Also, make sure they are fresh.
As for health concerns, I did find one article cautioning against green smoothies. This one talked about high levels of oxalates in greens and that too many greens can lead to oxalate stones in the body. You can read this article at:
http://www.thehealthyhomeeconomist.com/how-green-smoothies-can-devastate-your-health/
but unless you are downing 20 shakes a day, I don't think the average person should be concerned. I don't use a ton of greens in my shakes. It is very comparable to what I would eat in a salad or less. I also try to have only one type of each shake a day if I am having more than one. What I do like about the shakes from a health stand point is how it helps you eat a wide variety of fruits and veggies that I probably wouldn't eat too often together. I eat a lot of fruits and veggies already, but this just tops it off. I haven't read actual research, but I understand that the blending process can actually help you digest more of the vitamins and minerals from the plants better as well since you are breaking them up in the blender first.
Here's a picture of one of my green concoctions. I think this was the cinnamon apple one. Let me know if you want to try smoothies too and can't get my Pinterest recipe links! (Notice the soap in the blender - easy clean up and fun to watch!)
