Panic! Are cruciferous vegs killing my thyroid? I’m taking a stand on this issue.

A reader, Shawna, wrote us an email with tons of capitalized sentences and exclamation points, saying, "Hey! I've been doing green smoothies for a few years now! And I'm hypothyroid! Help–am I killing my thyroid?"

My customer support wrote me that people constantly write us "freaking out" about a widely circulated article on the internet saying that cruciferous vegetables essentially damage your thyroid gland. Crucifers include broccoli, kale, cabbage, and cauliflower.

People are susceptible to fear and paranoia–which are antithetical to empowerment and faith. I've written about this in Ch. 1 of 12 Steps to Whole Foods, but I need to take a stronger stand, since it's Top Five (questions I am asked, via email and everytime I speak in public).

As with food-combining theories (D'Adamo, etc.), or the idea that too many of one green food is "toxic" (Boutenko), or the idea that oxalates in greens harm us (another dubious internet-circulated claim)…..my reaction is like that line from Jerry Maguire, "Show me the money!"

My variation on that quote is, "Show me the data!"

Evidence that cruciferous vegetables are phenomenally powerful anti-cancer foods is voluminous. They also reduce bad estrogens; this is desperately needed by Americans, as we're daily bombarded with endocrine disruptors ("bad estrogens"). David Wolfe, in fact, says his favorite supplement of 2011 is Indole-3-Carbinol (I3C), which is an extract of the crucifers. I've been taking it myself.

The evidence that one compound in crucifers may have deleterious effects? It's limited and sketchy at best.

If we can isolate one compound (of dozens, maybe 100 or more) in green foods, and say that Compound X has Effect Y on Gland Z, how do we know that Compounds A, B, and C don't have mitigating effects on Effect Y? How do we know that the profoundly healing properties of Compounds D, E, and F in that same food don't work together synergistically with Compound X? The mountain of evidence that vegetables prevent disease suggests that foods are far more than the sum of their parts. Science still has little understanding of why plant foods are powerful, although in general, scientific communities like to break things down into parts and explain phenomena inductively. Let's back up and use some deductive reasoning.

The "articles" on the internet (read: people saying stuff–let's not give them undue credit by calling them articles) claim that LARGE AMOUNTS can damage the thyroid and increase the need for iodine. The entire American diet does both of those things–first, damage the thyroid, and second, increase the need for iodine (for instance, we eat salt stripped of iodine in virtually all our foods-- or that refined salt has chemical isolates of a toxic form of iodine put back in). So I'm highly skeptical of how any researcher isolated the "goitrogen" factor. Somebody please show me where that's been done.

Pick on the REAL bad guys here. Are we really going to flog cabbage and broccoli, when 95% of Americans are eating nuggets boiled in grease made of dozens of disease-infested chicken "parts" that if you looked at them each separately, you would wrinkle your nose and throw it in the garbage? And the same 95% are drinking tubs full of brown chemical liquids infused with carbon dioxide that contain absolutely no food?

About Shawna's question. Me, too–I've been hypothyroid AND I drink green smoothies daily. But in my case, it's been 17 years, not 3. My thyroid was all but destroyed because of nuclear fallout at the Nevada test site in the late 60's when I was a baby, drinking highly radioactive milk from cows who ate the radioactive fallout on the grass even hundreds of miles away.

Read the rest of my answer on the topic of goitrogens and thyroid (too long for the blog). Or just come back every day, and I'll post the rest in installments.....the next two days I have cool 3-min. videos for you!