The dark side of kale

Plants’ Natural Defenses
Plants have developed their own toxic substances to self protect - to discourage animals and people from eating them, and to protect them from plant pathogens and adverse environmental conditions. These toxic substances, as discussed in last week’s post, have come to be known as anti-nutrients. They are present in varying quantities in many foods. Small amounts won’t do much damage but in larger amounts they can interfere with your body getting adequate nutrition, and in excessive amounts they can even be fatal.

Raw isn’t necessarily best!
Raw foods are wonderful, delicious and nutritious, but they are not necessarily good for all conditions. Especially, not for thyroid troubles. The brassicaceae family of vegetables contains glucosinolates that can inhibit iodine uptake, resulting in hypothyroidism and promoting goiter formation.

Members of the brassicaceae family include cabbage, broccoli, cauliflower, Chinese cabbage, radishes, turnips, kohlrabi, rutabaga, collard greens, kale, Brussels sprouts, bok choy and watercress.

Many people think they are doing the best thing by putting raw kale into their smoothies. It’s actually not very smart: not only for thyroid health, but for kidney health, too. Kale, as well as spinach, contains high amounts of oxalates that can promote kidney stones and other painful deposits in the body, especially in people suffering with underlying fungal infections and candida overgrowth.  kale is also 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.

Here’s the science 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. 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.   http://lpi.oregonstate.edu/mic/food-beverages/cruciferous-vegetables

It’s the dose that makes a poison. If people have hypothyroidism or they’re taking thyroid medication, then they should check with their doctor. But even in this case, reasonable amounts shouldn’t be a problem.  Now, if people have a tall glass of kale juice every single day, then it gets into the unknown territory…but normal, reasonable amounts of eating should not be a problem. A regular person [with no thyroid issues] who eats several servings of cruciferous vegetables a week should not have problems.

Safer ways to include kale in your diet:

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. Alternatively, you can add a selenium supplement to your diet.

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. 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.

Traditional cooking methods can deactivate most of those anti-nutrients in these raw foods. Blanch kale in water, and then saute it in some fat (butter) to help your body absorb the beneficial minerals. And, skip the smoothies for a while. This doesn’t mean that you can never have another smoothie or raw kale salad, it just means to listen to your body, hear what it is saying, and make the necessary dietary adjustments that can facilitate healing.