by Raymond Peat, PhD
Chapter 11, from FROM PMS to MENOPAUSE: Female Hormones in Context
This book, and all of Dr. Peat’s books can be purchased by writing to: Raymond Peat, PhD, PO Box 5764, Eugene, OR 97405 USA
Measuring the amount of thyroid in the blood isn’t a good way to evaluate adequacy of thyroid function, since the response of tissues to the hormone can be suppressed (for example, by unsaturated fats).
In the 1930’s accurate diagnosis was made by evaluating a variety of indications, including basal oxygen consumption, serum cholesterol level, pulse rate, temperature, carotenemia, bowel function, and quality of hair and skin. A good estimate can be made using only the temperature and pulse rate. (Pulse rate should be thought of as an indicator of the rate of blood circulation, meaning that the strength of the pulse should increase with the rate; a rapid but weak, shock-like pulse gives useful information, but has a different meaning.)
Oral or armpit temperature, in the morning before getting out of bed, should be around 98 degrees F, and it should rise to 98.6 degrees by mid-morning. This is not valid if you sleep under an electric blanket, or if the weather is hot and humid. A person who is hypothyroid produces heat at a low rate, but doesn’t lose it at the normal rate, since there is less sweating, and the skin is relatively cool. Many hypothyroid people compensate with high adrenalin production (sometimes 40 times higher than normal), and this tends to keep the skin cool, especially on the hands, feet, and nose. The high adrenalin is the consequence of low blood glucose, so a feeding of carbohydrate, such as a loss of orange juice, will sometimes lower the pulse rate momentarily. Since thyroid is in essential for producing progesterone, and progesterone is “thermogenic” in the sense of setting the temperature control system higher, the body sometimes maintains a subnormal temperature even in warm weather. Healthy populations have an average resting pulse rate of about 85 per minute. Especially in hot weather it is useful to consider both temperature and pulse rate.
The Achilles tendon reflex is another quick way to estimate thyroid function. This reflex is used because of the insignificant weight of the toes in relation to contraction of the gastrocnemius muscle. The T (repolarization) wave on the electrocardiogram is a similar indicator of the rate of energy production. Thumping the Achilles tendon causes the muscle to contract (unless it is already in a semi-contracted state, which isn’t uncommon). The contraction consumes energy, and the muscle can’t relax until enough energy has been produced to restore the threshold and the readiness for a new contraction. (Creatinine levels are a vague indicator of the activity of this system, and are often a little low in hypothyroidism.)
If energy production is efficient, relaxation is faster than the passive return motion of the foot, so the foot swings freely back to its original position, and over-shoots slightly, causing a slight swinging action. In hypo- thyroidism, the foot returns as if controlled by a pneumatic door–closer, and settles slowly and precisely into its relaxed position, sometimes with a hesitating, intermittent motion. This slow replenishment of energy, and slow relaxation, can cause muscles to cramp easily. The aching leg muscles of children at the end of an active day are often a sign of hypothyroidism, and sometimes the gastrocnemius muscle become very swollen and hypertrophied in hypothyroid children. The same process, of slow energy regeneration, can cause rhythm disturbance in the heart, and often causes insomnia and restless sleep.
The thyroid gland secretes about 3 parts of thyroxin to one part of triiodothyronine, and this allows the liver to regulate thyroid function, by converting more of the T4 to the active T3 when there is an abundance of energy. Glucose is essential for the conversion, so during fasting there is a sharp decrease in metabolic rate, and in experiments, 200 or 300 calories of carbohydrates can added to the diet without causing fat storage.
When the liver is the main cause of hypothyroidism, your temperature (and especially the temperature of your nose, hands and feet) will fall when you are hungry, and will rise when you eat carbohydrates. If a hypothyroid person has a very slow pulse, and feels lethargic, it seems that there is little adrenalin; in this case, a feeding of carbohydrate is likely to increase both the pulse rate and the temperature, as the liver is permitted to form the active T3 hormone.
Women often have above-average thyroxin with symptoms of hypothyroidism. This is apparently because it isn’t being converted to the active form (T3). Before using a Cytomel (T3) supplement, it might be possible to solve the problem with diet alone. A piece of fruit or a glass of juice or milk between meals, and adequate animal protein (or potato protein) in the diet is sometimes enough to allow the liver to produce the hormone. If Cytomel is used, it is efficient to approximate the physiological rate T3 formation, by nibbling one (10 or 15 mcg.) tablet during the day. When a large amount is taken at one time, the liver is likely to convert much of it to the inactive reverse-T3 form, in a normal defense response.
Women normally have less active livers than men do. Estrogen can have a directly toxic effect on the liver, but the normal reason for the difference is probably that temperature and thyroid function strongly influence the liver, and are generally lower in women than in men. Estrogen inhibits the secretion of hormone by the thyroid gland itself, probably by inhibiting the proteolytic enzyme which dissolves the colloid. Progesterone has the opposite effect, promoting the release of the hormones from the gland. At puberty, in pregnancy, and at menopause, the thyroid gland often enlarges, probably as a result of estrogen dominance.
Thyroid function stimulates the liver to inactivate estrogen for secretion, so estrogen dominance can create a vicious circle, in which excess estrogen (or deficient progesterone) blocks thyroid secretion, causing the liver to allow estrogen to accumulate to even higher levels. Progesterone (even one dose, in some cases) can break the cycle. However, if the gland is very big, the person can experience a few months of hyperthyroidism, as the gland returns to normal. It is better to allow the enlarged gland to shrink more slowly by using a thyroid supplement. If an enlarged gland does begin to secrete too much thyroid hormone, it can be controlled with tablets of propylthiouracil, or even with raw cabbage or cabbage juice, and cysteine-rich meats, including liver.
Besides fasting, or chronic protein deficiency, the common causes of hypothyroidism are excessive stress or “aerobic” (i.e., anaerobic) exercise, and diets containing beans, lentils, nuts, unsaturated fats (including carotene), and undercooked broccoli, cauliflower, cabbage, or mustard greens. Many health conscious people become hypothyroid with a synergistic program of undercooked vegetables, legumes instead of animal protein, oils instead of butter, carotene instead of vitamin A, and breathless exercise instead of a stimulating life.
A good diet, plus a supplement of either thyroid or progesterone, can often break the cycle of hormonal imbalance.
If a person has at least a normal level of cholesterol, it is very likely that a progesterone deficiency can be corrected by normalizing the thyroid function, since thyroid, vitamin A, and cholesterol are the main factors in the synthesis of progesterone. If the problem is that the ratio of estrogen to progesterone is too high, though progesterone might itself be at a reasonable level, thyroid becomes crucial, to bring the estrogen level down to normal. In hypothyroidism there is a tendency to develop cystic ovaries, and low thyroid function normally leads to estrogen dominance, even if the ovaries seem normal.
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