I’m a big advocate of Green Smoothies, - I like to have one nearly every day and I regularly recommend them to people - however I always make sure I caution everyone to make sure they rotate their greens.
By this, I mean don’t use the same type of green every time. It is easy to get into the trap of liking one particular green, and just using that every day – however there are many green leafy vegetables which are in the Brassica family, and they contain plant chemicals which can inhibit the thyroid gland – so it is best to rotate this group of leafy greens regularly.
In the Brassica family you will find kale, cabbage, broccoli, (cauliflower and brussel sprouts – although I’ve never put those in my smoothie!), Bok Choy, Choy Sum and Pak Choi. These greens have wonderful healing properties, but need to be rotated with other greens such as, lettuce, dandelion, nettle, carrot or beet tops and spinach.
For a more comprehensive list of greens to use in a smoothie, and lots more information on how to source and identify wild greens – see Victoria Boutenko’s book Green For Life, and search out video’s by her son Sergei Boutenko who is a wild edible food expert.
You might want to read the account of one lady who overdosed on Bok Choy and caused herself a life-threatening thyroid condition. She was eating a LOT of Bok Choy though – 2-3 heads per day over several months. This can happen with any of the above Brassica family greens, although having enough iodine in the diet from eating plenty of sea vegetables will offset this effect somewhat.
But better to rotate those greens, just to be on the safe side!