In 1954, similar blended fruit and vegetable drink preparations      were published in                                           by Dr. Alice Chase.

In 1955, similar blended recipes called Sunshine Cocktails were included in                                                                   by G. Hauser.

These are some examples of very early green smoothie recipes from 1940, just two years after the introduction of the Waring Blendor which was the first modern electric blender on the market.  In 1954, the millionth Waring Blendor was sold. 

Green Smoothie History

Big Band Leader Fred Waring

In 1952, the recipes above were also published in a book titled                                                  by Mabel Stegner.