This study is fascinating and might make you think twice about green smoothies. It was designed to test the antioxidant properties of green tea extract. Since GTE was found to be all but useless, it ended up showing the effects of eating no vegetables for 10-weeks, since these had to be avoided.
The overall effect of the 10-week period without dietary fruits and vegetables was a decrease in oxidative damage to DNA, blood proteins, and plasma lipids, concomitantly with marked changes in antioxidative defence.
Greens have a ton of iron too, which is a health disaster for men, unless you happen to be a regular blood donor. Those alkalising diets are just nonsense. Obviously, we need some amount of vegetables for soluble fibre, vitamins, minerals etc, but it goes to show that you can’t trust anything the food pyramid tells you.