I have to believe iodine and selenium is fairly important especially if consuming goitrogens and fermented vegetables. My husband and I were consuming about 1-2 pounds of COOKED goitrogenic vegetables per day with no supplemental iodine or selenium. We were using sea salt which doesn't have much iodine. We started to develop symptoms like fatigue, feeling cold, cold hands etc. These symptoms happened in both low carb and higher carb contexts, although higher carbohydrate may mask thyroid symptoms - this was mentioned multiple times at Paleo FX in Austin.
Within days of slow adding kelp supplementation (building from 150 mcg to currently 975 mcg over a 6 weeks) and 150-200 mcg of selenium daily we notice a big difference in energy and not feeling cold. We have also limited our goitrogens by eliminating fermented vegetables since we do fine with raw dairy for probiotics.
We thought cooking and eating lots of saturated fat would take care of the goitrogens, but apparently that wasn't enough for us. So I compiled this list to help those trying to limit goitrogens or have had a similar experience.
Non-Goitrogenic Produce
Avocado - improves thyroid function
Banana, Plaintain
Berries (except strawberries), Cherries, Citrus (lemon, lime, grapefruit, orange, etc.), Melons
Apricots, Dragonfruit, Starfruit, Grapes, Guava, Kiwi, Lychee, Mango, Apple, Pineapple, Pomegranate
Nightshades - Peppers (sweet/bell and hot), Eggplant, Tomatoes, Potatoes
Squashes - Cabeza, Zuccinni, Yellow, Butternut, Pumpkin, Bittermelon (Corolla) technically fruit
Peas, Green Beans, Carrots
Okra
Asparagas, Artichoke
Lettuce, Celery, Cucumber
Herbs - Oregano, Basil, Thyme, Parsley, Cilantro, Parsley
Mushrooms
Onions, Leeks, garlic, shallots, chives
http://en.wikipedia.org/wiki/Goitrogen Goitrogens are substances that suppress the thyroid gland by interfering with iodine uptake, which can, as a result, cause an enlargement of the thyroid, i.e., a goitre.
Fermented Vegetables in brine (salt water) NOT vinegar have high Goitrogens since the bacteria convert more to that form as in Sauerkraut, Kimchi, Pickle, etc. Certain raw foods (cooking inactivates some of the goitrogens, except in the cases of soy and millet) have been identified as goitrogenic. These goitrogenic foods include:
Cassava (Tapioca), Sweet Potatoes, Rutabagas, Radishes (inc. Daikon), Turnips
Soybeans (and soybean products such as tofu, soybean oil, soy flour, soy lecithin) (High)
Pine nuts, Peanuts, Flaxseeds, Lima Beans
Millet (High)
Strawberries, Pears, Peaches (low)
Bamboo shoots
Spinach
Vegetables in the genus Brassica (cruciferous)
Bok choy, Choy sum, Mizuna Tatsoi,
Broccoli, Broccolini, Broccoflower, Kai-lan (Chinese broccoli), Rapini, Cauliflower
Brussels sprouts, Cabbage, Chinese cabbage
Canola (Rapeseed), Yu Choy,
Collard greens, Mustard Greens, Kale
Horseradish
Kohlrabi
Mustard (low)
Despite being generally a stimulant, caffeine (examples: coffee, tea, cola, chocolate) acts on thyroid function as a suppressant. Indeed some studies on rats suggest that excess caffeine in conjunction with a lack of iodine may promote the formation of thyroid cancers.
Masterjohn recommends no more then 5 servings of goitrogens/week and Kresser no more then 3-6 servings/week for anyone with thyroid issues.
Paul Jaminet, Chris Masterjohn, and Chris Kresser have written well on this.
http://www.westonaprice.org/basics/bearers-of-the-cross
Fermentation makes soy goitrogens worse! http://blog.cholesterol-and-health.com/2010/10/fermentation-does-not-neutrailize.html
