Well, yes, possibly. Here’s the science-y lowdown on the kale-thyroid connection from the Oregon State University Micronutrient Information site:
Very high intakes of cruciferous vegetables…have been found to cause hypothyroidism (insufficient thyroid hormone) in animals (68). There has been one case report of an 88-year-old woman developing severe hypothyroidism and coma following consumption of an estimated 1.0 to 1.5 kg/day of raw bok choy for several months. Two mechanisms have been identified to explain this effect. The hydrolysis of some glucosinolates found in cruciferous vegetables (e.g., progoitrin) may yield a compound known as goitrin, which has been found to interfere with thyroid hormone synthesis. The hydrolysis of another class of glucosinolates, known as indole glucosinolates, results in the release of thiocyanate ions, which can compete with iodine for uptake by the thyroid gland. Increased exposure to thiocyanate ions from cruciferous vegetable consumption or, more commonly, from cigarette smoking, does not appear to increase the risk of hypothyroidism unless accompanied by iodine deficiency. One study in humans found that the consumption of 150 g/day (5 oz/day) of cooked Brussels sprouts for four weeks had no adverse effects on thyroid function.
There are ways to have our kale and eat it too
Nina Manolson tells us that kale is a goitrogenic food, meaning that it can contribute to an enlarged thyroid — a goiter. A goiter indicates that the thyroid gland is not functioning optimally. But, she says, there are ways to have our kale and eat it too. Here, lightly edited, are her suggestions:
1. Cook Your Kale
The goitrogenic properties of kale become dramatically lessened when kale — or any other cruciferous vegetable — is cooked. (Other veggies in this category include: broccoli, brussel sprouts, cabbage, cauliflower, collard greens, kohlrabi, mustard, rutabaga, turnips, bok choy and Chinese cabbage. Arugula, horseradish, radish, wasabi and watercress are also cruciferous vegetables.)
2. Eat Seaweed
Kale on its own does not increase the risk of thyroid problems. It’s a combination of factors; including potential iodine deficiency. (One of the most common causes of goiters is iodine deficiency.) Adding seaweed or another iodine rich food to your diet may, in some cases, help you get adequate iodine.
3. Throw A Brazil Nut Into Your Smoothie
Selenium can support normal iodine levels which in turn may support a healthy thyroid. A Brazil nut or two in your daily smoothie or as a topping to any dish might help keep selenium levels strong.
4. Switch Up Your Greens
Vary your greens. If you’re going to eat kale one day choose a non-cruciferous, non-goitrogenic veggie dish the next, like a simple cucumber and tomato salad, or beets. There are many highly nutritious vegetables that aren’t goitrogenic, including celery, parsley, zucchini, carrots and more. Our bodies need many nutrients and by eating a variety of vegetables you’ll ensure that you don’t overload on one and skip another.
If you don’t have a thyroid issue, kale can and should be a delicious and healthy part of your diet because it is, indeed, a nutritional superstar with excellent credentials:
•It supports strong bones because of its high calcium content.
•It’s a potential immune booster, rich in Vitamin C.
•It may protect us against cancer because it’s packed with antioxidants and as mentioned, it’s a cruciferous vegetable.
•It’s high in iron which can support blood and energy levels.
•And of course, it’s packed with fiber so it’s great for digestion.
If you could take a multivitamin in food form, why wouldn’t you? This is why you need to try the ultimate superfood salad from The Roasted Root. It is densely packed with vitamins A and C, folate, potassium as well as fiber. The salad itself is made from kale, red cabbage, bell pepper, carrots, broccoli, walnuts, avocados tossed with ginger-lemon dressing. Try it as a refreshing entrée salad or serve a smaller portion as a side.
To log this recipe, search the food database for: MyFitnessPal Ultimate Superfood Salad
Ultimate Superfood Salad
For the Dressing
- 1/4 cup grapeseed oil
- 1/2 cup lemon juice, fresh
- 1 tablespoon ginger, peeled and grated
- 2 teaspoons whole grain mustard
- 2 teaspoons pure maple syrup, optional
- 1/4 teaspoon salt, or to taste
For the Salad
- 2 cups dinosaur kale, tightly packed and thinly sliced
- 2 cups red cabbage, thinly sliced
- 2 cups broccoli florets
- 2 large carrots, peeled and grated
- 1 medium red bell pepper, sliced into matchsticks
- 1/2 cup fresh parsley, chopped
- 1 cup walnuts
- 1 tablespoon sesame seeds
- Optional Topping: 2 medium avocados, diced
Whisk together all ingredients for the dressing (or put everything in a small blender and blend) and set aside until ready to use.
Add the kale, cabbage, broccoli, bell pepper, and carrots to a large serving bowl.
Pour desired amount of dressing over the salad and toss until everything is coated.
Add the parsley, sesame seeds and walnuts and toss again. Top with avocado if desired. May be served as an entrée salad or as a side salad to your favorite meal.
Serves: 8 | Serving Size: 1/8 of salad (does not include avocado)
Per serving: Calories: 290; Total Fat: 23g; Saturated Fat: 3g; Monounsaturated Fat: 6g; Cholesterol: 0mg; Sodium: 138mg; Carbohydrates: 13g; Dietary Fiber: 6g; Sugars: 5g; Protein: 5g
Nutrition Bonus: Potassium: 653mg; Vitamin A: 120%; Vitamin C: 142%; Calcium: 9%; Iron: 10%