The Secret Dark Side Of Kale


I've written a lot about kale and my fanaticism for it.  I know of few foods more nutrient-rich, detoxifying and generally promoting of vibrant health.  Synchro Salad Recipes Version Two and Version Three are both habit-forming-delicious kale salad recipes that I eat almost every day of my life.  "Almost" is an important word there, because for all the amazing qualities kale brings to the table (literally)'s not perfect.

Kale contains a couple organic compounds that have the potential to create issues...but only if you eat a TON of kale.  Thankfully, there's no reason to ever have to deal with these issues.  Using a bit of biochemistry knowledge combined with some clever strategy, we can get all of the benefits of kale with none of the potential issues.

Who Is This Relevant For?

The answer is that this issue is relevant only for a minority of us.  For most people, keep aiming to get as much kale in your diet as possible.  This will only do great things for you well-being and performance.

If you're like me and eat huge amounts of kale almost every day of the week, this article is for you.  To be more specific: if you eat 1/2 (large) bunch of raw kale or more 4 or more days a week, you should know and implement the techniques described below.

Why Kale Is F'ing Awesome

Here's the short list of what raw kale delivers:

  • 800% Daily Value (DV) Vitamin A and 2400%(!) DV Vitamin K  (approx. in one salad)
  • Loads of Trace Minerals and Phytonutrients
  • High Levels of Antioxidants
  • Anti-Inflammatory
  • Lutein and Zeaxanthin for your eyes
  • Enzymatically Active and Living

But really, let's be honest about why so many people so fanatical about kale: eating raw kale feels awesome.  The sum of the nutritional qualities of kale really does no justice to the experience.  There is something about eating raw kale that makes us feel alive and vibrant in a way that few other things do.

Issue #1: Oxalates

Oxaltes are natural chemicals produced by kale as a defense mechanism.  Almost all plants produce oxalates or similar chemicals to protect themselves against being overeaten by insects in their environment.  Without these "defense chemicals", insects would often eat leaves to the point of killing the plant.  Oxalates work as a defense mechanism because in the body they will bind with calcium to form tiny crystals.  In the case of a snail or beetle that might eat its bodyweight in kale in a single meal, these crystals can be a serious problem.  For humans (even a kale fanatic such as myself) it would take years of high oxalate-consumption for these crystals to accumulate to the point of creating even minor issues...but it can happen.  Oxalate-calcium crystals can form in muscles and connective tissues, producing gout-like symptoms (gout is similarly caused by the accumulation on uric acid crystals).

Fortunately, our bodies are quite adept at clearing oxalates out of our systems.  Even if you're eating kale on a daily basis, the body will naturally clear out most of the oxalic acid you eat.  This is why it takes years (if ever) for crystals to accumulate.  If you eat kale only a few times a week (and aren't eating a ton of other oxalate-containing foods like buckwheat, amaranth, rhubarb, chard, beets, etc), you'll likely never run into any issues.

Oxalates: The Fix

As I mentioned above, it's when oxalates bind with calcium in tissues in the body that they have the potential to create issues.  So what if we can get oxalates to bind to calcium before they make it into tissues?  That's the essence of the strategy here.  

The technique is to "pre-load" with calcium before you eat kale.  With this technique, your digestive system will have a ton of free calcium floating around that will bind to the oxalates in your GI tract as the kale is digested.  This allows the oxalates to be excreted as waste before they have the opportunity to make it into muscles, joints or other tissues in the body.

Synchro Recommendation: Take 500-1000mg of both calcium and magnesium with your kale salad or shake.  I take 2 capsules of a Calcium-Magnesium supplement as I'm starting to eat my salad.  For my morning kale shake, I'll actually cut open the capsules and dump them in to the blender so they start binding to oxalates before they even get into my stomach.

(why magnesium? as I've written about previously, magnesium is hugely important for a large number of processes in the body.  A lot of these functions require a balance between magnesium and calcium.  Since some of the calcium we "pre-load" with will be absorbed by the body and not bind to oxalates, we need to make sure we keep calcium and magnesium in balance) 

Issue #2: Goitrogens

Goitrogen is a term used to refer to any compound that inhibits the absorption of iodine into the thyroid gland.  (when the thyroid can't get enough iodine, it can enlarge to attract more.  extreme cases of this result in goiters.  hence the name)  The thyroid is responsible for the production and regulation of a large number of hormones, and plays a particularly significant role in energy metabolism and body fat management.  Naturally, we want our thyroids working perfectly - and that means making sure it has adequate iodine to perform all of its functions.  

Kale contains glucosinolates, a mild type of goitrogen.  In line with our intention of getting all of the benefits of kale with none of the issues, we need a strategy for dealing with these compounds.

(Like oxalates, goitrogens will never be an issue for most people.  Even fanatical kale-eaters will likely never experience any level of thyroid suppression.  That being said, this technique addressing the issue is simple, so being over-cautious certainly can't hurt.  For people with thyroid issues, however, this becomes more relevant.)

Goitrogens: The Fix

First, it's important to make sure that we're not handicapping our thyroid gland before we even begin to address the goitrogen issue.  Iodine is a notoriously difficult nutrient to get in adequate quantities through diet alone.  This is why iodine was added to table salt beginning in the 1920's.  I advocate doing more specific iodine supplementation to make sure your thyroid has more than enough iodine available.  I take 600mg Kelp capsules as part of my daily supplementation regimen, which gives me ~400 micrograms of iodine (2.5x the FDA's recommendation).  Overcompensation with iodine supplements intake will go a long way to address issues created by goitrogens.

Our second strategy is to maximize the body's natural mechanisms for dealing with these compounds.  Kale is hardly the only source of goitrogens, so naturally the body is quite capable of eliminating them from the body.  To maximize this, we can implement a strategy called greens cycling, where for a period of several days we'll substitute in non-goitrogenic greens for kale in our salads and shakes.  For a block of 4-5 days out of every month I'll substitute spinach in my shakes and spinach/mixed greens in my salads.  Spinach only has a fraction of the nutritional content of kale, but it also lacks goitrogens, allowing the body to clear these compounds out during the cycle.  I also double my kelp supplementation during the cycle, loading my thyroid with iodine.  The thyroid will hold onto iodine for a while, so "loading" during your greens cycling will offset any iodine suppression from kale consumption.

Kale: Still The Best Thing Out There

This is an interesting article to write, as it seems to condemn my single favorite food on the planet.  It's important to note that foods with no issues are few and far between.  The issues presented by kale pale in comparison to those associated with other common foods.  Mycotoxins from grains, glycemic load and Omega 3/6 balance are three of many examples of issues that are way higher on my priority list than any issue associated with kale.  Even if the issues with kale were left unaddressed, I still consider it a big net positive to eat it on a daily basis.  But since we're trying to optimize every aspect of our diet, mitigating these issues with kale is the natural step.

So in conclusion: "Eat More Kale"...just do it in the smartest way possible.

Stay Synchro,

     Graham Ryan




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