In Thyroid Thursday Episode 68 Dr Eric Balcavage discusses the connection between hypothyroidism and oxidative stress.
Hi, everybody. It’s Dr. Eric Balcavage, and today, I want to talk about hypothyroidism and something called oxidative stress. This will probably be a two-parter, but today, in part one, we’re going to talk about:
- what oxidative stress is
- the role of thyroid hormone in helping to prevent oxidative stress
- when you have hypothyroidism, why oxidative stress can get out of control
What is this thing called oxidative stress?
That’s what we need to start with. Well, oxidative stress is the damage that’s caused by the free radicals produced during energy production. What does all that mean? Your cells make energy, and specifically, the mitochondria make most of the energy (when you don’t have hypothyroidism). That’s why you have the ability to run around and your brain works and your skin isn’t dry and your metabolism works. It’s all because of what’s happening in these engines inside your cells called your mitochondria. Well, to produce energy, the cells and the mitochondria require oxygen. Oxygen is used to generate that energy, but there’s a by-product in that energy process, and the by-products are called free radicals, or reactive oxygen species.
When you burn wood and produce fire and heat, there’s also a by-product, which is the smoke. You can think about free radicals and these reactive oxygen species like the smoke. The cells need to do something with these free radicals that are generated. They need to degrade them and get rid of them, or if they accumulate, they can create some problems (cellular damage).
When you have healthy thyroid physiology, you have a much better ability to address these free radicals that are produced. When you have cellular hypothyroidism (often not represented by a TSH or blood levels of T4 and T3), you have less thyroid hormone reaching the cells. Reduced active thyroid hormone to support cell metabolism decreases your cell’s ability to deal with these reactive oxygen species so they build up and accumulate in the cells and create damage.
Mitochondria generate energy, which we call ATP. There’s also a by-product of that energy process, and those are these free radical products. Things we call reactive oxygen species: superoxide, hydrogen peroxide, and hydroxyl groups. Don’t worry about the chemistry, though. Just know that those things occur. In normal healthy situations, the body produces enzymes to help get rid of these free radicals. I’ll talk about that in a second.
Free radicals, these reactive oxygen species, when they are produced, one of two things is going to happen to them. Your cells are going to get rid of them, and that helps you maintain healthy mitochondria and healthy cells. Or, they can accumulate. If these free radicals and reactive oxygen species accumulate, we get cell damage. What we call oxidative stress. Oxidative stress is the damage caused by these free radicals, which drives pathology, which causes cell aging, and eventually, we see it as disease.
Thyroid hormone helps us to reduce oxidative stress via three mechanisms.
One is that thyroid hormone, especially T3, inside your cells increases the activity and expression of something called your uncoupling protein. The uncoupling protein is associated with heat energy. When you’re producing this energy within the mitochondria, we want to make sure that we’re making the amount of energy that we can manage. If we have more energy being produced then we can really effectively manage, one of the things the body does is increase these uncoupling proteins to divert energy down a path that can generate more heat.
The second thing thyroid hormones do to reduce oxidative stress is increase something called mitochondrial potassium ATP channels. As your cells are generating energy, they’re pumping some minerals out, some minerals come in. Calcium can wind up building up in the cells, and potassium gets dumped out of the cells. If you get too much calcium coming into the cells, that can become toxic.
The thyroid hormones are needed to support the mitochondrial potassium ATP channels. Activated thyroid hormone (T3) can increase the activity of this pump so that the excess calcium is pumped back out, and the potassium that was lost from the cell to the blood can be pumped back in. It keeps the balance of minerals within the cells in balance.
The third way that thyroid hormones help decrease oxidative stress is that they increase the expression and the activity of antioxidant enzymes. Thyroid hormones, especially T3 inside the cells is critical for the function of something called superoxide dismutase. Superoxide dismutase which is one of the enzymes that’s responsible for breaking down free radicals. Thyroid hormone is also essential for the expression and function of other antioxidants like catalase and glutathione peroxidase.
If you have reduced T3 inside your cells, this condition we call cellular hypothyroidism, your antioxidant enzymes aren’t going to work. You’re going to build up these free radicals, and that’s going to create the symptoms of oxidative stress, which I’ll talk about in a second.
Thyroid hormone also has an impact on your antioxidants like vitamin A, vitamin C, vitamin E, cysteine, glutathione, selenium, ceruloplasmin, and transferrin, just to name a few. T3 is essential for these things to be made and to function appropriately. Loading the body with these things when your cellular levels of thyroid hormone are deficient isn’t going to help you too much.
Let’s review what cellular hypothyroidism is. That cellular hypothyroidism is decreased T3 inside your cells. This can be caused by:
- Decreased production by the gland. If the gland is damaged or destroyed, and you’re not producing sufficient T4 and T3, then there isn’t sufficient T4 and T3 potentially in the bloodstream, and there won’t be sufficient T4 and T3 reaching your cells, so cellular hypothyroidism can be caused by lack of glandular production. This is usually not the number one cause.
- Decreased thyroid hormone transport into the cells. You can have optimal levels of T4 and T3 in the blood, but if it’s not being transported appropriately inside the cells, you can have cellular hypothyroidism.
- Decrease conversion of T4 to T3 and increase conversion of T4 to reverse T3, the inactive form of thyroid hormone.
When we have decreased T3 inside our cells, and we have this increased conversion of T4 to reverse T3, then we lose our cell’s ability to control the levels of free radicals inside the cells. We lose the ability to properly regulate the uncoupling proteins. We lose the ability to regulate these potassium ATP channels. We lose the ability to activate our natural antioxidant enzymes and antioxidants.
This all results in symptoms of oxidative stress; things like fatigue, brain fog, decreased memory. We see it as muscle and joint paints, wrinkles and gray hair, decreased eyesight, headaches, increased blood pressure, increased cholesterol. The damaged caused by oxidative stress is the reason most people are prescribed medications.
For today’s Thyroid Thursday I want you to understand that cellular hypothyroidism plays a major role in causing oxidative stress, and damage to your cells and tissues. Cellular hypothyroidism is heavily associated with early aging and disease.
In most cases of hypothyroidism, the big issue is that you don’t always need more thyroid hormone. The big issue we must consider is what’s causing the deactivation of thyroid hormone once it reaches the cells. Deactivation of thyroid hormone is typically being driven by some form of stress: physical, chemical, emotional, or microbial.
A good functional medicine practitioner isn’t just going to give a bunch of supplements. We’re not going to tell you to go on medications for all these signs and symptoms. What we’re going to try and get you to do is modify diet and lifestyle to help reduce the stressors that are triggering the cell dangerous response.
It’s the cell danger response which is triggering the cellular deactivation of thyroid hormone. It’s the cellular deactivation of your thyroid hormone that is reducing your cell’s ability to deal with oxidative stress appropriately. It’s the deactivation of thyroid hormone and your cell’s reduced ability to reduce the free radicals and the oxidative stress that is causing your symptoms.
This is such a big topic. There’s so much complexity to it. I’ll follow-up with part two soon. If you have any questions regarding hypothyroidism and its impact on causing reactive oxygen species and oxidative stress, put your comments wherever you watch the video, and I’ll be sure to get back to you.