The thyroid gland has an important affect on the rate of metabolism in the body by the production of a hormone called T4 and the peripheral conversion of T4 into the more metabolically active T3 or reverse T3. The hypothalamus is constantly checking the need for more metabolic energy in body and in response to falling levels of T4 and T3 it releases a hormone called Thyroid Releasing Hormone (TRH). The only significant role of TSH is that it stimulates the thyroid gland to produce thyroid hormone. This is a simple understanding of the regulation of thyroid hormone; when the brain tissue is exposed to more thyroid hormone the hypothalamus produces less TRH. The pituitary gland then produces less TSH and the thyroid makes less thyroid hormone.

THYROID HORMONES:

The three hormones that the thyroid gland secretes are the following:

* Thyroxin (T4) – Deficiencies of zinc, copper and vitamins A, B2, B3, B6 and C will cause a decrease in production of T4 by the follicles of the thyroid gland.
* Triiodothronine (T3) – Is the most metabolically active thyroid hormone 4-5 times more than T4. About 80-85% of T3 is produced outside the thyroid by conversion of T4 in the liver and kidneys and the enzyme responsible for this conversion is selenium dependent 5’-deiodinase.
* Calcitonin this hormone is involved with calcium metabolism

EFFECT S OF THYROID HORMONES:

* Increase cellular metabolic activity by increasing the number and activity of mitochondria
* Promote growth and development
* Stimulates carbohydrate metabolism
* Stimulates fat metabolism
* Has an effect on plasma and liver fats
* Increases basal metabolic rate
* Decreases body weight
* Has an effect on the cardiovascular system- increase of blood flow, cardiac output, heart rate and heart strength
* Increases respiration
* Increases gastrointestinal motility
* Excitatory effect of the central nervous system
* Increases the rate of secretion of most all other endocrine glands
* Has an effect on sexual function

Thyroid hormone is transported through the blood stream by Thyroid Binding Globulin (TBG) which is produced in the liver. TBG is affected by several factors such as the following:

* Liver dysfunction
* Liver disease
* Oxidative stress, antioxidant insufficiency and lipid peroxidation within liver
* Heavy metals (cadmium, mercury and lead)
* Toxicity: Fluoride, pesticides, radiation, PCBs, dioxins, phthalates
* Medications: Beta blockers, Birth control pills, Estrogen, Lithium, Phenytoin,
* Theophylline, Chemotherapy, Glucocorticoids, Interleukin 6, Clomipramine
* Kidney health

Lifestyle factors also have an effect on peripheral metabolism of thyroid hormones. The following factors have been shown to influence deiodination leading to decreased circulation of T3 levels and increased circulation of rT3 which is not ideal.

* High stress and elevated cortisol levels
* Selenium deficiency

A diet

* High in cruciferous vegetables(goitrogen containing foods)
* Low protein
* Low fat
* Low carb
* Increased alcohol use
* Soy
* Walnuts
* Poor nutrition and nutrient deficiencies: iodine, iron, selenium, zinc vitamins A,B2,B3, B6, B12
* Fasting
* Calorie restriction
* Lack of exercise
* Alcohol intake

It is important to note that enough of these factors will lead to thyroid dysfunction. Often it may not be a lack of thyroid hormone that is the problem, but dysfunction in the liver and/or kidney and associated lifestyle factors that cause the presentation of hypothyroidism.

MANIFESTATIONS OF HYPOTHYROIDISM:

* Fatigue, weight gain, anemia, cold intolerance
* Dry course skin, brittle hair, hair loss, non-pitting edema
* Hearing loss, hoarse voice, periorbital edema, facial puffiness
* Goiter
* Dyspnea, pleural effusions, hypoventilation, sleep apnea
* Bradycardia, congestive heart failure, pericardial effusions
* Anorexia, constipation
* Menstrual disorders, decreased libido, impotence, infertility
* Muscle weakness, delayed ankle jerk relaxation phase
* Depression, psychomotor retardation

Primary Hypothyroidism:

This is a problem located in the thyroid gland when it fails to produce thyroid hormone. It is often preceded by autoimmune thyroid disease.

* TSH levels increased above 2.0
* Normal or decreased total T4 level
* Increased cholesterol

Secondary Hypothyroidism:

In secondary hypothyroidism the problem is due to anterior pituitary hypo function which fails to produce optimum levels of TSH to stimulate the thyroid. Thus thyroid hypo function is secondary to anterior pituitary dysfunction and this condition is becoming more and more common. It is often mistaken for thyroid hypo function.

* A decreased TSH
* A decreased T-3 uptake
* A normal T-4, T-3 and FTI

The likelihood of secondary hypothyroidism increases if serum triglycerides are elevated and total cholesterol are increased.

Tertiary Hypothyroidism:

In tertiary hypothyroidism the hypothalamus shuts down protectively in response to stress and produces low levels of TSH, T4 and T3. This often linked to chronic fatigue syndrome and fibromyalgia. This condition can cause low body temperatures, a tendency towards infections and other metabolic consequences of low thyroid. It has also been suggested that problems with the mitochondria the cellular structures that supply us with energy may cause the suppression of the hypothalamus.

Late Stage Hashimoto’s Disease:

This condition is marked by decreased T4 and gradual hypothyroidism due to the auto-antibodies has already destroyed much of the glandular tissue and there’s not many cells left to produce T4. Now there is adrenal fatigue and hypothyroidism.

CORRECTING HYPOTHYROIDISM:

These are some of the questions that need to be considered:

1. Does the body have adequate precursors for the synthesis of T4? This would include nutrients such as;

* Iodine
* Tyrosine
* Adequate dietary protein

2. Is there a need to reduce anti-thyroid antibodies? These would include:

* Gluten more and more evidence points to a connection between gluten intolerance, celiac disease and autoimmune thyroiditis
* There is a relationship between casein or milk protein intolerance and hypothyroidism.

3. Is there a need to reduce xenobiotics load? Certain environmental toxins can cause autoimmune thyroiditis and research continues to show the role xenobiotics play in thyroid dysfunction.

4. Is there a need to work on increasing peripheral conversion of T4 into active T3? Selenium deficiency is a factor here as well as adrenal dysfunction (excess cortisol) interferes with peripheral conversion.

5. Is there a need to improve the binding of T3 to intracellular receptors? Remember that T3 interacts with intracellular receptors at the level of the mitochondrion to effect energy production. This process requires adequate levels of vitamin A and Omega-3 EFAs (EPA and DHA).

FOODS AND NUTRIENTS THAT SUPPORT T4 SYNTHESIS

1. Iodine: from fish, sea vegetables like kelp, dulse, arame, hijiki, nori, wakame, kombu and sea salt.

2. Tyrosine: from eggs, green beans, lean meat (beef and chicken), peas, seafood (fish), sea weed and yogurt.

3. Zinc: from pumpkin seeds, sunflower seeds, squash seeds, organ meats, shrimp, oysters, herring, green beans, eggs, onion, spinach, chick peas.

4. Vitamin E: Nuts

5. Vitamin A : Fish liver oils, animal fats egg yolk, leafy green vegetables, yellow and orange fruits

6. Vitamin B2: Beef liver, kidney, tuna, chicken, salmon, almonds, avocado.

7. Vitamin B3: Brewer’s yeast, rice bran, white meat of chicken and turkey

8. Vitamin B6: Watermelon, banana, chicken, organ meats, leafy green vegetables, legumes

9. Vitamin C : Citrus fruits and most fruits and vegetables

10. Copper: liver and other organ meats, eggs, legumes, nuts and raisins

FOODS AND NUTRIENTS THAT SUPPORT PERIPHERAL CONVERSION OF T4 INTO T3:

1. Zinc

2. Selenium: brewer’s yeast, organ muscle meats, fish, shellfish, kelp.

FOODS AND NUTRIENTS TO SUPPORT T3 BINDING TO INTRACELLULAR RECEPTORS:

1. Vitamin A

The key to correcting Hypothyroidism is to detect the underlying causes of the condition and a protocol designed to correct those causes which would include dietary changes, targeted supplementation, detoxification, lifestyle modifications and appropriate exercise.

REFERENCES:

Functional Endocrinology Module: Functional Medicine University, 2009.

Author's Bio: 

Basil Butcher is a former National level under 19 cricketer and tennis player in his native Guyana. Basil has been educated in the health and fitness fields by the CHEK Institute; C.H.E.K. Level IV Practitioner and Holistic Lifestyle Coach Level III. National Academy of Sports Medicine; Sports Fitness Specialist and International Sport Sciences Association as a Fitness Trainer, Fitness Therapist and Specialist in Sports Conditioning. He is also a certified Neuromuscular Therapist(St. John Method), certified Advanced Metabolic Typing Advisor Level II, certified in Functional Diagnostic Nutrition and Functional Diagnostic Medicine.

Basil has consulted with the following organizations: Guyana National Cricket Team, Demerara Cricket Board, New York Cricket Region Youth Cricket Program. He is the Physio/Trainer for the Atlantic Cricket Region U-19 and Senior cricket teams. He was the Physio/Trainer of the USA National U-19 Cricket team that played in the 2006 ICC Youth World Cup in Colombo, Sri Lanka.

He has worked with West Indies cricketers such as Ramnaresh Sarwan, Reon King, Colin Stuart and Neil McGarrell. He has worked with 7-time World Masters Power Lifting Champion and world record holder Ellen Stein, LPGA Golf Pro Mary Enright, World and National Masters swimming champion Kristin Gary and drummer Cindy Blackman. He has worked with people from all walks of life and athletes from sports such as baseball, basketball, cricket, cycling, golf, power lifting, wrestling, swimming, soccer and American football.

Basil has presented seminars and lectures in Guyana and throughout the New York Metro area on topics such as Functional Back Training, Functional Shoulder Training, Holistic Program Design, Stress and Your Health and From Injury to the Playing Field.

Basil has maintained an Integrative Performance Enhancement Coaching private practice in New York City for the past 12 years.

Basil specializes in the following areas:

Personal Training/Coaching

Rehabilitation Conditioning for Back, Neck, Shoulder, Hip and Knee Conditions/Pain.

Integrated Weight Loss/Functional Diagnostic Medicine

Advanced Metabolic Typing

Performance Enhancement for Life/Sport