Kale contains many beneficial nutrients, but it’s not good idea to eat these hearty raw leafy greens on a continual basis. Kale is a goitrogenic vegetable and when eaten raw, this vegetable can inhibit the uptake of iodine by the thyroid gland. If it’s eaten in excess, these chemicals can inhibit the incorporation of iodine into thyroid hormone. This is a process that iodine supplements can’t reverse. (Source: Chris Kesser via The Thyroid Sessions)
The body relies on iodine (and tyrosine) to make thyroid hormones, so continually eating these raw greens can cause a thyroid hormone imbalance.
Raw kale is also contains oxalic acid, which binds with minerals such as calcium and magnesium in the body causing them to crystalize. These crystals can damage tissues, cause inflammation in the body and kidney stones. So, a daily dose of raw kale and other goitrogenic vegetables may not be such a great idea.
A simple way to decrease the goitrogenic properties in raw kale is to boil it for seven minutes, drain and squeeze the excess water out. This will reduce the goitrogens by about 90%. After boiling, the kale is ready for a soup, smoothie or to scramble in your morning eggs. That’s it!
Here is a list of other goitrogenic vegetables that should be eaten cooked (and preferably with animal fats to improve assimilation of their nutrients):
I enjoy having kale in my smoothies, so I boil the kale, drain it and then freeze it in an ice cube tray. The pic below is one I shared over on Instagram, (the hearts are kinda fun, right?). It’s an extra step, but this way I always have some on hand!
Today I’m sharing a recipe for a green smoothie without as many goitrogens! I call it the “perfect” green smoothie, because not only does it have wonderful flavor and ultra-creamy texture, but it contains boiled kale (less goitrogens), vitamin A from the egg yolks to help the body detox (your body can’t detox without Vitamin A (aka retinol) from animal sources) and unflavored grass-fed gelatin for extra protein.
This is an incredibly nutrient-dense smoothie that will keep you going for several hours. My kids love this smoothie and it makes for extra-creamy green popsicles.