Take a closer look at your thyroid function with this commonly overlooked test!
Nearly every day, I hear patients complain that they have symptoms of low thyroid. They’ve gained weight… feel tired all the time… are constipated… and just can’t stand the cold. They may even experience some swelling.
Yet, they’ve been told by their doctors that their thyroid test results were ‘normal.’ Well, if you’ve been reading my Nutrition & Healing newsletter and eTips emails for a while,
you know by now that most mainstream doctors’ standards don’t even come close to mine.
I want my patients’ levels to be more than ‘normal’ or ‘average.’ I don’t want you to feel ‘OK’ or ‘fine’ – I want you to feel great! Thyroid function in particular is more complicated than a single blood test result.1 To make sure you’re getting the optimum performance out of this critical gland – which can stimulate metabolism, lower cholesterol, and improve healing – it’s important to explore other ways of testing for thyroid issues.
And it may involve a lab test that I’m betting your physician has barely heard of – but that you can ask for! The usual test performed by doctors is a TSH (thyroid stimulating hormone) test. This test is fine if you’re looking specifically for low thyroid due to thyroid damage (mostly due to an autoimmune condition called ‘Hashimoto’s Thyroiditis’).
But to get the real story of what’s going on with your thyroid – especially if you’ve been experiencing weight gain, fatigue, and other ‘classic’ symptoms – you may need a lab test called ‘Reverse T3,’ or rT3 for short.
Peel back the layers of how your thyroid actually works
In order to understand rT3, you’ve got to understand something of the activity of thyroid hormones in the body. Thyroid hormones are made up of an amino acid called ‘L-Tyrosine,’ to which iodine atoms are added. The bulk of the thyroid hormone released into the bloodstream is T4, or L-Tyrosine with four iodine atoms added.
Many factors are involved in the proper production of T4 by the thyroid, besides the obvious candidates of both L-Tyrosine and iodine. A number of other nutrients are critical to the production of T4 by the thyroid, including:
• Vitamins E, D, and C
• B vitamins (specifically B2, B3, and B6)
• the minerals iron, zinc, and selenium.
If any one of these important nutrients is missing, the thyroid gland is unable to keep up with production demands from the body, and it won’t be able to produce enough T4.
Many other conditions in the body will lead to a lessening of thyroid function and slow the production of T4 at the gland site (sometimes referred to as a ‘down-regulating’ of thyroid hormone production).
These include toxins such as mercury, lead, pesticides, and cadmium. Fluoride, a known neurotoxin that interferes with iodine in the body, has also been implicated.2 Infections, radiation, trauma, and various medications can block thyroid function. And autoimmune diseases, particularly celiac disease (extreme gluten sensitivity), do the same. And so can stress.
How ‘normal’ test results happen
It’s perfectly common for a patient’s thyroid to produce a proper amount of T4. When that happens, the pituitary gland thinks everything is ok and puts out a normal amount of TSH.
The end result is that the patient suffers from the symptoms of hypothyroidism without showing abnormalities of the standard lab tests that measure TSH – because even when your thyroid IS producing enough T4, it isn’t very active in the body.
In fact, T4 needs to be converted into T3 (L-Tyrosine + 3 iodines) before it can do much of anything at all. So, here’s yet another stage at which point something can go wrong with your thyroid function – yet most doctors aren’t even looking for it. In fact, a number of the same conditions that prevent the thyroid gland from producing T4 can also interfere with the proper conversion from T4 to T3 (like stress), as well as:
• inflammation (with elevation of cytokines and other pro-inflammatory messengers)
• infections (including chronic ones like Lyme Disease)
• medications, and
• problems with other organs such as liver and kidneys.
And this is where reverse T3 (rT3) enters the picture. In situations of stress to the body, cells convert T4 into a different hormone, called rT3, which is much less active than regular T3. Even a low-calorie diet will favour the conversion to rT3 over T3. This is why some people have such a hard time losing weight, even when they’re on a very stringent diet. Their body metabolism slows down as more T4 is converted to the metabolically less active thyroid hormone, rT3.
Since rT3 looks so much like T3, it actually competes with T3 to attach to the binding sites of the body’s cells. And when it attaches, it is much less active in its effects, plus it prevents the regular T3 from performing its duties. The end result is a slower metabolism, even in the face of normal thyroid production of hormone.
Only the complete picture will lead to a cure
Whenever I’m evaluating thyroid function, I look at a variety of factors. I do measure TSH of course, as well as T4. Specifically, I look at the ‘free’ T4, which is the one that’s unbound to anything.
But I also look at free T3 (fT3) and reverse T3. The ratio of rT3 versus fT3 is a critical measure. Even if the patient has already been put on a synthetic version of T4 called levothyroxine (commonly known by the brand names Levoxyl and Synthroid), I might give them some T3 if their ratio is off.
I tend to prefer a natural glandular medication over synthetics – so I might recommend Armour thyroid hormone replacement therapy, which contains both T3 and T4.3 Nature Throid is another natural alternative to synthetics that also contains both T3 and T4, but it’s also gluten- and corn-free. Both are made from animal products, so they’re not suitable for vegetarians or vegans.
You need a prescription from a doctor for either Armour or Nature Throid. You don’t want to go trying to fix your own thyroid without the benefit of some knowledgeable medical advice.
But don’t forget an ounce of prevention
More critically, their test results will likely lead me to go looking for toxins, infections, deficiencies, and other situations that would lead to this result. That way, I can address the root cause of the reduced thyroid function. Needless to say… if stressors can sabotage the proper function of thyroid hormone production, conversion, and attachment… then by all means find a way to reduce or eliminate that stress to your body!
Exercise can give you the extra boost you need, and can help jumpstart your metabolism as well. I should note that since the proper conversion of T4 into T3 – and the proper attachment of T3 to cell binding sites – requires a good amount of zinc and selenium available in your body, you can naturally support your thyroid function with supplements. You can get both of these essential minerals by taking a good multivitamin along with eating a nutrient-rich diet, although they’re available individually as well at your local health food store.
While you’re at it, make sure you’re getting proper levels of vitamin A and B vitamins.
Wishing you the best of health,
Dr. Glenn S. Rothfeld
Nutrition & Healing
Vol. 10, Issue 9 • September 2016
Full references and citations for this article are available in the downloadable PDF version of the monthly Nutrition and Healing issue in which this article appears.