Thyroid Hormones

www.gizmag.com

 The thyroid is “The Master Hormone” that controls everything in our body.  One of the biggest reasons our thyroids slowdown is due to iodine deficiency in addition to aging.  40% of us are at risk for iodine deficiency and hypothyroidism.  Not giving our bodies the nutrients that are important for a healthy thyroid will also slow your thyroid down.  The body does not make iodine.  It relies on the diet to get enough.

The thyroid hormones, triiodothyronine (T3) and thyroxine (T4), are tyrosine-based hormones produced by the thyroid gland that are primarily responsible for regulation of metabolism.  Iodine is necessary for the production of T3 and T4. A deficiency of iodine leads to decreased production of T3 and T4, enlarges the thyroid tissue and will cause the disease known as goitre.

The thyronines act on nearly every cell in the body.  They act to increase the basal metabolic rate, affect protein synthesis, help regulate long bone growth (synergy with growth hormone) and neural maturation, and increase the body's sensitivity to catecholamines (such as adrenaline) by permissiveness.  The thyroid hormones are essential to proper development and differentiation of all cells of the human body.  These hormones also regulate protein, fat, and carbohydrate metabolism, affecting how human cells use energetic compounds.  They also stimulate vitamin metabolism.  Numerous physiological and pathological stimuli influence thyroid hormone synthesis.

We can easily maintain adequate iodine through our diets by using table salt because it’s fortified with iodine, but most of us need to restrict or limit our sodium causing iodine deficiencies to show up.  Many medications also slow down the thyroid and also cause iodine deficiency.  Medications that make you feel sleepy or slow may also slow your thyroid and your metabolism down even more.

www.nature.com

PHYSIOLOGIC EFFECTS OF THYROID HORMONES

Thyroid hormones enter cells through membrane transporter proteins.  Once inside the nucleus, the hormone binds its receptor, and the hormone-receptor complex interacts with specific sequences of DNA in the promoters of responsive genes.  The effect of the hormone-receptor complex binding to DNA is to modulate gene expression, either by stimulating or inhibiting transcription of specific genes. 

Thyroid hormones have profound effects on many "big time" physiologic processes, such as development, growth and metabolism.  Deficiency in thyroid hormones is not compatible with normal health.  The effects of thyroid hormone:

Metabolism	·        Thyroid hormones stimulate diverse metabolic activities of most tissues, leading to an increase in basal metabolic rate. ·        One consequence of this activity is to increase body heat production. ·        A few examples of specific metabolic effects of thyroid hormones include: o   Lipid metabolism: §  Increased thyroid hormone levels stimulate fat mobilization, leading to increased concentrations of fatty acids in plasma. §  They also enhance oxidation of fatty acids in many tissues. §  Plasma concentrations of cholesterol and triglycerides are inversely correlated with thyroid hormone levels - one diagnostic indiction of hypothyroidism is increased blood cholesterol concentration. o   Carbohydrate metabolism: §  Thyroid hormones stimulate almost all aspects of carbohydrate metabolism, including enhancement of insulin-dependent entry of glucose into cells and increased gluconeogenesis and glycogenolysis to generate free glucose.
Growth	·        Thyroid hormones are clearly necessary for normal growth in children and young animals. ·        the growth-promoting effect of thyroid hormones is intimately intertwined with that of growth hormone, a clear indiction that complex physiologic processes like growth depend upon multiple endocrine controls.
Development	·        A classical experiment in endocrinology was the demonstration that tadpoles deprived of thyroid hormone failed to undergo metamorphosis into frogs. ·        Of critical importance in mammals is the fact that normal levels of thyroid hormone are essential to the development of the fetal and neonatal brain.
Other Effects	·        As mentioned above, there do not seem to be organs and tissues that are not affected by thyroid hormones. A few additional, well-documented effects of thyroid hormones include: o   Cardiovascular system: §   Thyroid hormones increases heart rate, cardiac contractility and cardiac output. §  They also promote vasodilation, which leads to enhanced blood flow to many organs. o   Central nervous system: §  Both decreased and increased concentrations of thyroid hormones lead to alterations in mental state. §  Too little thyroid hormone, and the individual tends to feel mentally sluggish, while too much induces anxiety and nervousness. o   Reproductive system: §  Normal reproductive behavior and physiology is dependent on having essentially normal levels of thyroid hormone. §  Hypothyroidism in particular is commonly associated with infertility.

www.metabolicprecision.com 

THYROID DISEASE

Disease is associated with both inadequate production and overproduction of thyroid hormones.  Hypothyroidism may be the reason you’re overweight.  There are many causes of hypothyroidism.

Hypothyroidism

§  is the result from any condition that results in thyroid hormone deficiency. §  Two well-known examples include: o   Iodine deficiency: §  Iodide is absolutely necessary for production of thyroid hormones; §  without adequate iodine intake, thyroid hormones cannot be synthesized. §  Historically, this problem was seen particularly in areas with iodine-deficient soils, and frank iodine deficiency has been virtually eliminated by iodine supplementation of salt. o   Primary thyroid disease: §  Inflammatory diseases of the thyroid that destroy parts of the gland are clearly an important cause of hypothyroidism. §  Common symptoms of hypothyroidism arising after early childhood include lethargy, fatigue, cold-intolerance, weakness, hair loss and reproductive failure. If these signs are severe, the clinical condition is called myxedema. In the case of iodide deficiency, the thyroid becomes inordinantly large and is called a goiter. §  The most severe and devestating form of hypothyroidism is seen in young children with congenital thyroid deficiency. If that condition is not corrected by supplemental therapy soon after birth, the child will suffer from cretinism, a form of irreversible growth and mental retardation. §  Most cases of hypothyroidism are readily treated by oral administration of synthetic thyroid hormone. In times past, consumption of dessicated animal thyroid gland was used for the same purpose.

Hyperthyroidism

§  results from secretion of thyroid hormones. §  In humans the most common form of hyperthyroidism is Graves disease, an immune disease in which autoantibodies bind to and activate the thyroid-stimulating hormone receptor, leading to continual stimulation of thyroid hormone synthesis. §  Another interesting, but rare cause of hyperthyroidism is so-called hamburger thyrotoxicosis. §  Common signs of hyperthyroidism are basically the opposite of those seen in hypothyroidism, and include nervousness, insomnia, high heart rate, eye disease and anxiety. §  Graves disease is commonly treated with anti-thyroid drugs (e.g. propylthiourea, methimazole), which suppress synthesis of thyroid hormones primarily by interfering with iodination of thyroglobulin by thyroid peroxidase.

HYPOTHYROIDISM

One of the most important factors that leads to hypothyroidism is exposure to environmental toxins such as pesticides, which act as hormone or endocrine disruptors and interfere with thyroid hormone metabolism and function.  One study found that as people lost weight they released pesticides from their fat tissue.  The toxins created a slow metabolism and prevented them from losing more weight.

Heavy metals such as mercury can also affect thyroid function.  The other big factor that interferes with thyroid function is chronic stress.  There is an intimate interaction between stress hormones and thyroid function.  The more stress you are under, the worse your thyroid functions.

The next major factor that affects thyroid function is chronic inflammation.  The biggest source of this chronic inflammation is gluten, the protein found in wheat, barley, rye, spelt, and oats.  This chronic inflammatory response interferes with thyroid function.  Nutritional deficiencies play a big role in thyroid dysfunction. These include deficiencies of iodine, vitamin D, omega-3 fats, selenium, zinc, vitamin A, and the B vitamins.

There are so many reasons for low thyroid function.  Take the following steps to rebalance your thyroid:

§  Make a thorough inventory of any of the symptoms that you might suffer from hypothyroidism.

§  Get the right thyroid tests including TSH, free T3, free T4, TPO, and anti-thyroglobulin antibodies.

§  Check for celiac disease with a celiac panel.

§  Consider heavy metal toxicity.

§  Check your vitamin D level.

The seven-step plan to address hypothyroidism developed by Mark Hyman:

1.   Treat the Underlying Causes — like food allergies, gluten, heavy metals, nutritional deficiencies, and stress.

2.   Optimize Your Nutrition –including foods that contain iodine, zinc, omega-3 fats, selenium, and more.

3.   Minimize Stress – eliminate adrenal exhaustion and minimize stress by engaging in a comprehensive stress management program.

4.   Exercise – Engage in thyroid stimulating exercise, which boosts thyroid function.

5.   Supplement – Use supplements to help enhance thyroid function, including all the nutrients needed for proper thyroid metabolism and function.

6.   Heat Therapy – Use saunas and heat to eliminate stored toxins, which interfere with thyroid function.

7.   Thyroid Hormones – Use thyroid hormone replacement therapy to help support your thyroid gland.

If you have hypothyroidism, take thyroid hormone replacement as directed by your doctor — generally with an empty stomach.  It's also important to note that too much dietary fibre can impair the absorption of synthetic thyroid hormone.

HYPERTHYROIDISM

Hyperthyroidism means a raised level of thyroid hormone.  Thyroxine is a body chemical (hormone) made by the thyroid gland.  It is carried around the body in the bloodstream.  It helps to keep the body's functions (the metabolism) working at the correct pace.  Many cells and tissues in the body need thyroxine to keep them going correctly.

Hyperthyroidism means an overactive thyroid gland.  When your thyroid gland is overactive it makes too much thyroxine.  The extra thyroxine causes many of your body's functions to speed up.  (In contrast, if you have hypothyroidism, you make too little thyroxine; this causes many of the body's functions to slow down.)

The following are symptoms of hyperthyroidism:

§  Being restless, nervous, emotional, irritable, sleeping poorly and 'always on the go'.

§  Tremor of your hands.

§  Losing weight despite an increased appetite.

§  Palpitations.

§  Sweating, a dislike of heat and an increased thirst.

§  Diarrhoea or needing to go to the toilet to pass faeces more often than normal.

§  Shortness of breath.

§  Skin problems such as hair thinning and itch.

§  Menstrual changes - your periods may become very light or infrequent.

§  Tiredness and muscle weakness may be a feature.

§  A swelling of your thyroid gland (a goitre) in the neck may occur.

§  Eye problems if you have Graves' disease.

Pay close attention to how you feel.  Treat your thyroid naturally to keep it working at an optimal rate so you never have a problem with it slowing down.  Here are three things you can do to boost your thyroid function:

1.   Eat more of these great sources of iodine to enhance thyroid function:

·        Low fat cheese

·        Cow’s milk

·        Eggs

·        Low fat ice cream

·        Low fat yogurt

·        Saltwater fish

·        Seaweed (including kelp, dulce, nori)

·        Shellfish

·        Soy sauce

2.   Eat less of these foods; they slow your thyroid because they block your thyroid and your medication from producing thyroid hormone properly, especially when eaten raw.  Cooking these foods inactivates their anti-thyroid properties.  These foods are called goitrogens, which are chemicals that lower thyroid function. Eat these foods sparingly or only once every four days:

·        Almonds

·        Cauliflower (Any vegetable that falls into the broccoli family is a goitrogen and shouldn’t be eaten more than twice a week if you have hypothyroidism.)

·        Millet

·        Pears

·        Turnips

·        Brussels sprouts

·        Corn

·        Mustard

·        Pine nuts

·        Cabbage

·        Kale

·        Peaches

·        Soy (Isoflavones block iodine)

·        Canola oil

·        Peanuts

·        Spinach

3.   Workout every day.  For optimal thyroid function, exercise at least three days a week for 40 minutes per workout.  working out/walking every day is strongly suggested so that your thyroid gets a boost daily to correct the condition until your thyroid is running at an optimal rate.  Circuit training is also great way to lower insulin levels and increase thyroid function.  This is easy to do in the comfort of your own home by doing pushups, lunges and sit-ups back to back without rest, pushing yourself a bit to get out of breath.

You can still lose weight even if your thyroid is not working properly by taking a few simple steps.

1.   Enhance your thyroid with supplements.

Take thyroid-enhancing supplements daily to gently and safely keep your thyroid working optimally for life.  Supplementing is the best way to keep your thyroid running at an optimal rate and to keep your weight under control.  Start your supplement regime first by using a very strong, high quality multivitamin.  Most store-bought vitamins are not suitable or strong enough to help hypothyroidism, so look for a very potent high quality multi with high levels of iodine, selenium, zinc, vitamin B, D, E and at least 2 grams of vitamin C. Other nutrients such as omega-3 as well as amino acids also help regulate the thyroid and need to also be considered. One of my favorites that I put all of my hypothyroid clients on is gugglesterones. Guggulsterone or guggulipid’s have been used for centuries in ayurvedic medicine to naturally regulate the thyroid and keep it running at an optimal rate without the side effects of medications.  Look for supplement multitaskers from a very reputable source so you don’t have to take 29 different pills every day.

References:

1.    3 Ways to Boost Thyroid Function By Lisa Lynn; http://www.doctoroz.com/

2.    Mechanism of Action and Physiologic Effects of Thyroid Hormones; http://www.vivo.colostate.edu/

3.    Thyroid hormone; http://en.wikipedia.org/

4.    A 7-Step Plan to Boost Your Low Thyroid and Metabolism by Mark Hyman, MD; http://drhyman.com/

5.    Is there any truth to the hypothyroidism diet? Can certain foods increase thyroid function? Answers from Todd B. Nippoldt, M.D.; http://www.mayoclinic.org/

6.    Hyperthyroidism (Overactive Thyroid); http://www.patient.co.uk/