I recently summarized my personal experience with how the changes in my diet have affected my thyroid in the review on I wrote on Jimmy Moore’s Keto Clarity.  If you’d like to read about my history more in detail you can refer to these posts:

• The Effects of a Ketogenic Diet on Thyroid Hormone Part 1
• The Effects of a Ketogenic Diet on Thyroid Hormone Part 2
• The Effects of a Ketogenic Diet on Thyroid Hormone Part 3
• Cyclic Ketogenic Diet and Thyroid Hormone
• Carb Back-Loading and Thyroid Hormone

Here are my latest numbers:

When looking at all the numbers, it’s interesting to note how similar they are to my numbers from 12/16/2013 after 10 weeks of Carb Nite.

The TSH, Free T4, Free T3, and rT3 are all virtually identical.  Looks like the 10 days of eating low carb prior to the test really started to affect my thyroid.

Reverse T3

This is the one value I’m still not sure what to make of.  To quickly review the physiology of all this, the thyroid releases Free T4 into blood stream.

The peripheral tissues that receive Free T4 convert it into the Free T3, the more potent form of thyroid hormone.

Under certain conditions, the body becomes inefficient at converting Free T4 to Free T3 and instead shunts the Free T4 into reverse T3 which is the inactive form of thyroid hormone.

I’ve tried to learn more about this and can’t really find much on PubMed.  All the information out in Google seem to be from alternative / complimentary medicine type of sites.  Whenever I encounter the lack of PubMed information AND a preponderance of alternative-y sites dedicated to a subject it always gives me a reason to pause.

I never get to a level where I dismiss it outright… but it definitely still makes me think twice.

Anyways, here are a couple site I came across with some information on the subject of Reverse T3:

• Custommedicine.com.au
• Tiredthyroid.com
• Holistic-hypothyroidism-solutions.com

Here’s a link for the more reputable Mayo Clinic Medical Laboratories.

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A couple other posts that I’ve come across that I’ve found helpful describing the relationship between low carb and changes in the thyroid:

• Dr. Cate Shanahan – I’ve referred to this same post a while ago, but I’ll link it again here.  She’s part of Mark Sisson’s Primal Advantage program.  In this post she describes reading about people that have gone low carb and developed elevated rT3, and thinks this is mainly due to going low carb too abruptly.  She says that she’s been able to avoid this problem in her patients by transitioning them to low carb gradually over time.
• Team Chris Kresser – While this article wasn’t written by Chris Kresser himself, he does discuss this in his book The Paleo Code.  Chris Kresser was the first person I heard describe the importance of insulin in facilitating the conversion of T4 to T3, and when there is a lack of insulin, as seen in a low carb diet, the T4 is shifted to the rT3 pathway instead.  This is one of those facts that I haven’t been able to find supported in PubMed, so… who knows.
• Anthony Colpo – This is probably the most comprehensive article I’ve read on the subject with multiple citations.  It’s a very long read but I’d encourage you to read it if you’re interested at all in this subject.  He examines numerous studies demonstrating the relationship between the necessity of carbs and maintaining normal thyroid function.  In the end he does caution placing too much importance on having normal thyroid hormone numbers since the human body is so complex and there are many other hormones at work.

From doing reading all these sites it seems that the potential causes for an elevated reverse T3 include:

• Chronic stress – (Yes!  I think my shift work may play a role)
• Lack of dietary antioxidants – (I think I’m pretty covered by taking Athletic Greens regularly)
• Chronic alcohol or drug abuse – (Nope)
• Low calorie diets or fasts – (Yes, since I think ketosis falls in this category)
• Liver and kidney disease – (Nope)
• Toxic heavy metal exposures – (Not sure)
• Diabetes – (Nope, we just saw that my fasting insulin is fine)
• Severe trauma – (Nope, I’d know if I had this)
• Septic or hemorrhagic shock – (Nope)
• Cold exposure – (Nope)
• High cortisol – (Maybe, because of my shift work, but my fasting blood sugars aren’t that high so not sure)
• Medications like Amiodarone and beta blockers – (Nope)
• Nutrient deficiences – (Maybe?  Although I expect the Athletic Greens and Thorne Multi-Vitamin Elite have me mostly covered)
  • Iron
  • Selenium
  • Zinc
  • Chromium
  • Vitamin B6 and B12
  • Vitamin D
  • Iodine

What do I plan to do?

Many of the treatments I’ve come across consist of directly replacing T3 with thyroid hormone supplements.  This is a step I’m not wiling to take at this point, so I’d rather try some other less drastic things first.

Since I can’t do much about my shift work, all I can do is to try to minimize the stress I encounter and optimize what little sleep I get as much as possible.  I really suspect this plays a significant role in why my rT3 is so high and my Free T3 is in the bottom of the normal range.

I’ve also recently started taking Kiefer’s T3 Fuel which consists of:

• Potassium Iodide 100 mcg
• Magnesium Citrate 100 mg
• Zinc Sulfate 15 mg
• Selenium (as L-Selenomethionine) 300 mcg
• Watermelon Fruit Extract 400 mg
• Resveratrol 250 mg
• L-Tyrosine 250 mg
• L-Carnitine Tartrate 200 mg

Kiefer talked about it a bit in his Insulin Timing Tricks Webinar (see my notes here and here).  He asserts that his supplement will maximize the health of mitochondria which can be compromised when they are subjected to a carb based diet for a prolonged period of time.  He also states that it’s still important to have the occasional carb spike and that T3 Fuel is just a powerful adjunct… but not a complete replacement for the weekly carb nite.

I’ve decided to take T3 Fuel for a full 30 days and then I’ll recheck my thyroid panel to see if anything has changed.  If things improve then I’ll know that T3 Fuel works and that a lot of my issues were related to micronutrient deficiencies AND potentially mitochondrial dysfunction.  Who knows… if it works it may even help me with my body composition!

If it doesn’t work… well you better believe I’ll let Kiefer know about it AND I’ll have yet another addition to my supplement graveyard.

Incidentally, one of my favorite resources to go to is Stop The Thyroid Madness.  On their reverse T3 page they suggest solutions like using natural dessicated thyroid, synthetic T3, selenium, and even milk thistle!  If the T3 Fuel doesn’t work I might just pick up their latest book, Stop the Thyroid Madness II,  to learn more about what this is all about.

Stay tuned…