Smoothies are definitely a good thing. I would just recommend putting a higher amount of veggies into the smoothie than fruit. Fruit is good for you in moderation, but remember that it contains much more sugar than most veggies. True, fructose is natural sugar, but it still affects our bodies the same way re: blood sugar level spikes/drops and pH acidity - whereas veggies are alkaline, which is great for keeping cancer away
One thing I add to my smoothies is chlorella powder - just a tablespoon. Chlorella is packed with cancer-fighting nutrients. I also like to use some coconut milk, which gives the smoothie a fluffier texture without adding sugar. And I generally throw in some chia seeds, too.