Wednesday, May 20, 2015

Dr. Sara Gottfried, MD says...

Kale and Spinach and your beautiful Thyroid
Dr. Sara, I thought we weren't supposed to eat raw kale or spinach because it’s bad for your thyroid?? CONFUSED
Kale is considered a goitrogenic food, meaning it contains substances (goitrogens) that may contribute to an enlarged thyroid. The two mechanisms identified are running interference with thyroid hormone synthesis and competing with iodine for uptake by the thyroid gland.
All cruciferous vegetables are considered goitrogenic, including arugula, bok choy, broccoli, brussel sprouts, cabbage, cauliflower, collard greens, mustard greens, turnips, and watercress.
The research I have done tells me that the risk of the general public having problems in this area are very, very low. The vast majority of people have adequate iodine levels to counteract the effect of goitrogens.

So, what’s the bottom line here?
For the general population, the many health benefits of eating kale and other cruciferous vegetables in usual amounts far outweigh any potential adverse risks to the thyroid. The risks of worsening a preexisting thyroid condition are likely minimal if goitrogenic foods are consumed in (again) reasonable amounts. I myself am hypothyroid and I enjoy kale.
Cooking helps inactivate goitrogenic compounds, so don’t shun these foods, especially considering their other healthful superpowers. The work around for those who are hypothyroid is to gently steam whatever cruciferous veggies you eat and freeze before using.
I don’t advocate drinking massive amounts of green juice. Raw juicing often includes goitrogenic vegetables like cabbage and spinach, and these juices end up providing highly concentrated amounts of goiter-promoting ingredients. (But I don’t encourage massive consumption of any one single food either). Chew on a variety of whole green veggies and get the fiber benefits! Otherwise, eating them raw a couple times a week is fine. They contain so many nutrients and minerals that support thyroid health including calcium, vitamin C, iron, fiber, and antioxidants.
So kale on good people, just be a mensch, avoid juicing, and add more players to your greens repertoire.