We are busy rotating greens in our smoothie world. Plants have traces of alkaloids and too much of any one green (over many weeks) can actually produce symptoms of poison in your body. Plants, and our bodies, were created this way so that greens would last and not become extinct. What an Intelligent Design!
Incidentally, fruits do no contain these alkaloids so eat away, your apple a day!
This smoothie contains red leaf lettuce, beet & carrot tops, and some cilantro. I threw in an orange and lemon