Your Metabolism and Your Hormones
Your metabolism is the speed at which your body burns off the energy contained in food.
In this article we’ll examine the hormonal control of your metabolism.
Your Personal Metabolism
Food contains energy in the form of calories which is used by the body. We all vary in how quickly we burn off this energy.
A person with a sluggish metabolism will use energy relatively slowly. They won’t need to take in as many calories as someone with a fast metabolism who burns off energy quickly.
So if your metabolism is slow, you may tend to put on weight.
The thyroid gland can be thought of as the body’s accelerator pedal, and it’s the major influence on the speed of your metabolism.
If the thyroid isn’t functioning optimally, the body will have problems obtaining energy and the result can be weight gain and fatigue. If the thyroid is revving too quickly this is also not a good thing because we’ll tend to lose weight, sweat excessively, and experience palpitations and anxiety.
The Thyroid Hormones
The thyroid produces two types of hormone, thyroxine (T4) and triiodothyronine (T3). The thyroid needs iodine to produce these hormones.
The difference between the two types of thyroid hormone is the quantity of iodine they contain. T3 is the more active form, although it’s produced in smaller amounts than T4. T4 is converted to T3 as needed by taking away an iodine ion.
Some of the thyroid hormones piggyback onto a protein to be transported around the bloodstream and released when free levels of the thyroid hormones are low.
Thyroid hormones affect almost every cell of the body. They are transported across the cell membrane and bind to receptors in a part of the cell called the mitochondria. The mitochondria is known as the powerhouse of the cell, and it’s where energy production occurs. Almost all body cells contain mitochondria and some areas which use large amounts of energy such as muscle cells have more mitochondria than others.
Thyroid hormones cause the mitochondria to produce ATP from glucose. ATP provides the energy needed to drive processes within the cell. Thyroid hormones are also believed to activate genes involved in energy production.
Low Thyroid Function
Because thyroid hormones can turn our metabolism up or down, low levels of these hormones can literally slow us down. Although a sluggish metabolism is usually connected with weight gain, other symptoms include constipation, fatigue, feeling the cold and difficulties concentrating.
Official figures state 1-2% of the population suffer from low thyroid function, known as hypothyroid, but many doctors and practitioners believe the figure is much higher than this. This is because conventional thyroid function tests will often miss cases of low thyroid.
Hypothyroid symptoms may occur because too few thyroid hormones are manufactured, either because the brain doesn’t instruct the thyroid properly, or there’s a shortage of the raw materials, particularly iodine, needed for hormone manufacture. Symptoms may also be a result of poor conversion of T4 to T3. In some cases, the thyroid gland can become inflamed because it’s mistakenly attacked by the immune system.
On the subject of mitochondria, a condition called mitochondrial dysfunction is characterised by the inefficient production of ATP by the mitochondria. This can cause extreme long-term fatigue, intolerance to exercise, muscle pain and weakness and low blood pressure.
Mitochondrial dysfunction can be caused by mutations in the DNA of the mitochondria. This in turn is thought to be related to free radical damage from oxidative stress.
There’s a close relationship between thyroid hormones, mitochondrial activity and oxidation.
Support Your Thyroid
Thyroid supporting measures include managing your stress, avoiding toxic metals such as mercury and fluoride and supporting your liver which is where the conversion of T4 to T3 occurs.
Prevention of oxidative stress is important for both thyroid and mitochondrial health. Eating a wide variety of colourful plant-based foods will provide plenty of protective antioxidants. As their name implies they prevent oxidation from damaging cells.
Getting enough sleep is vital as this is when the body repairs damaged cell components, including the mitochondria. Too little sleep can slow the metabolism.
Functional Medicine and Your Metabolism
If you are constantly tired or experiencing any of the other symptoms of thyroid dysfunction, a Functional Medicine consultation can test the levels of your thyroid hormones, both active and inactive, as well as assessing other factors which may be impacting your metabolism.
Other tests examine substances in your urine to assess how effectively your mitochondria are functioning, as well as determining your levels of oxidative stress.
In this way, the causes of your symptoms may be identified. Personalised lifestyle and nutritional strategies can then be recommended to support the functioning of both your thyroid and your mitochondria. Contact me today to book a consultation.