Thyroid

Thyroid hormone is the fundamental catalyst for oxidative metabolism, making possible all higher biological functions by enabling cells to use oxygen and produce carbon dioxide efficiently. 2 Peat argued that without the metabolic efficiency promoted by thyroid, life could not advance beyond the single-cell stage; it is the trigger for making endless amounts of carbon dioxide, which stabilizes the electronic balance in cells and sits at the heart of everything living. 2 The basic function of thyroid is to energize cells sufficiently to allow differentiation, preventing organisms from concentrating solely on eating and growing, which in humans can lead to tumors and malformations. 3

The active thyroid hormone is triiodothyronine (T3), which is mostly produced in the liver from thyroxine (T4) depending on the availability of glucose, allowing a sensitive adjustment of metabolism to nutrition. 9 When thyroxine is added to brain tissue in vitro, it suppresses respiration, but T3 increases respiration in any tissue. 9 Peat emphasized that the medical community's reliance on TSH measurement as an indicator of hypothyroidism is problematic because TSH itself has pro-inflammatory actions, increasing fibrinogen and making blood more viscous; he considered a TSH between 0.0 and 0.4 the safe range. 5 A major effect of thyroid is controlling the conversion of cholesterol into pregnenolone, progesterone, and other protective steroid hormones; excess cholesterol usually indicates thyroid or vitamin A deficiency. 2

Thyroid function is intimately tied to the stress system. When thyroid is adequate, the pituitary and adrenals have an easy job; when thyroid is interfered with, the pituitary becomes a commander-in-chief driving stress hormones. 6 Peat described a personal experience where his own metabolic rate was approximately three times normal due to stress, and taking thyroid brought it down to normal within days, allowing him to build muscle. 2 He interpreted this through the lens of magnesium and ATP: when cells are de-energized, magnesium is lost and calcium associates with ADP, creating a stress state that thyroid can correct. 2 Thyroid, especially T3, relieves depression by correcting a state of stress and lowering chronically elevated cortisol, making sleep efficient and restful rather than debilitating. 8

Several factors interfere with thyroid function. Unsaturated oils block proteolytic enzymes involved in hormone release, interfere with T4-to-T3 conversion in the liver, and inhibit tissue response to the hormone in proportion to the number of double bonds. 9 A deficiency of polyunsaturated fatty acids is anti-estrogenic, partly by allowing the thyroid-stimulated liver to excrete estrogen. 9 Stress hormones produced by allergy cause the liver to convert thyroxine to reverse T3, lowering thyroid function in a kind of defensive semi-hibernation. 10 Peat noted that bad foods interfering with thyroid create hyperventilation at the very beginning; no matter how much you breathe, if your thyroid is underactive, your body experiences hyperventilation. 4 Without adequate thyroid, tissues cannot function normally, leading to sluggishness, coldness, anemia, susceptibility to infections, heart disease, cancer, and premature aging. 1