Arugula, broccoli, Brussels sprouts, bok choy, cabbage, cauliflower, chard, collard greens, daikon, kale, kohlrabi, mustard greens, radishes, rutabaga, turnips, and watercress.
Cruciferous vegetables are good for you, right? They’re high in fiber. They’re mineral- and vitamin-rich. They contain isothiocyanates, which help the body fight carcinogens. And for purposes of Martin’s specialized diet, they’re not too starchy or sugary.
But nothing in the world of autism is a slam-dunk, really. I’ve been warned against feeding Martin any raw cruciferous vegetables. That may not seem like a big deal. On the other hand, I love dehydrated kale chips, and Martin used to love them, too—an easy, on-the-go snack available without moderation.
Now he doesn’t get them anymore, at least not often. With the familiar caveat that I am neither a scientist nor a doctor (and I give no medical advice), here’s my understanding of why raw cruciferous vegetables can affect ASD: Thyroid functioning is key to brain function and mental health. Many environmental chemicals, including BPA and flame retardants, are endochrine disruptors, which means that they can interfere with thyroid functioning and thereby hinder the developing brain. Cruciferous vegetables, while unquestionably not the same kind of thyroid criminals as those aforementioned synthetic chemicals, naturally contain chemicals known as goitrogenic isothiocyanates, or simply “goitrogens” (think “goiter”). The goitrogens inhibit the body’s metabolism of iodine, which is crucial to the production of thyroid hormone. Decreased hormone production means poor thyroid functioning. Poor thyroid function has been tied to autism.
This video from The Renegade Health Show explains (if you can tolerate big words, and lots of them) the effects of isothiocyanates on thyroid function. Kevin on the video concludes that only iodine-deficient persons, or those with pre-existing thyroid problems, need to worry about raw cruciferous vegetables. (And even those people may be able to counter the effects of the goitrogens by boosting their iodine intake.)
Most commentators seem to agree that cooking cruciferous vegetables, even lightly, inactivates the goitrogenic effects, which is why this concern applies primarily to raw cruciferous veggies.
So should Martin avoid them entirely?
I agree with Renegade Health’s Kevin that raw cruciferous vegetables pose no risks for the majority of the population. More specifically, I agree that they pose no risks for me; I eat buckets of arugula salad, I dip raw cauliflower in hummus, and I’m pretty sure that my life would be a lesser existence without the Dijon-marinated raw kale at Sacred Chow in the Village.
At the same time, whereas ASD and thyroid complications often travel together, allowing Martin to eat raw cruciferous veggies may well be a sort of danger.
I’ve decided to strike a balance. (I like saying that, because it must often seem like I’m willing to go any extremes, whatever the issue.) To ensure that Martin gets ample iodine, even without dietary supplementation per se, I sprinkle kelp flakes on his food in place of salt. Then I’m careful not to allow him unrestricted access to raw cruciferous veggies. Instead, he gets only the two foods he adores most: kale chips and green vegetable juice. I prepare kale chips no more than a couple times per month. As to the green vegetable juice—which in our case comprises organic green leafy vegetables (for goitrogen purposes, spinach is mildly better than kale or cabbage), cucumber, ginger, celery, lemon, and half an apple—it’s really a double no-no, because of the one-half apple. Nevertheless, I let Martin drink up to 12 ounces once per week.
As a side note, I consider dehydrated kale chips raw because they’ve not been heated to more than 115 degrees Fahrenheit, or 46 degrees Celsius. Definitions of “raw,” for purposes of the raw-food movement (which is not the topic of this post), vary. They include insisting that food be unheated and recommending that it not be heated above human body temperature. I’d love to wade into that debate, and more raw foods in general—but I keep returning to my mantra: There are only so many hours in the day.
And of those hours in this day, I’ve probably just given too many to the topic of goitrogens.