I worked in a juice bar years ago and served the recreational to the hardcore. A few of the hardcore juicers looked jaundice due to extremely high intake of carrot juice.
Like anything, moderation. Depending on the components you can dump a lot of sugar into your system fast - often not a good thing. Those relying on juice to increase their intake of fruit/veg are missing much of the health value derived from the fiber.
That said, I like an occasional juice. My favorite is:
3 medium beets
2 medium carrots
1 small apple or pear
half a bunch of parsley
a chunk of ginger to taste
(I choose smaller items which fit my juicers feed chute to eliminate chopping)
My friend juices and I am the beneficiary. I'll have to ask him about the details but boy does he go through the organic carrots.
I used to read the sunday funnies and there was a very eccentric one called The Strange World of Mr. Mum. His adventures almost always ended with a visit to the juice bar so I am thrilled to find out how smart that guy was!
If you try it be careful, it can be addicting. Half a glass and I feel instantly better and energized. Perfect for getting through a difficult task when you start to fade.
The owner of the raw vegan cafe in my town is always telling people to add not subtract. I think some of the trouble is when people go on a juice fast. I hate it when they get all cutesy and call it a juice feast. Don't get me started with that and "uncooking". Grrr. I'd advise taking it slow and just adding a cup or two of juice to your daily diet and see how your body reacts.
I live in the NE and spring is just starting here. When the weather gets warmer I may have to add a second refrigerator. Beats me where it's gonna go but all that produce is bulky and I don't want to lose food to the heat and fruit flies. And shopping daily is a bad idea for me.
As always, the devil is in the details, but I think it's worth it for the health benefits and instant mood boost.