| Your
Thyroid and You
Yun
Hwang
Your
thyroid is a small, unassuming organ in your neck next
to your esophagus. Being an endocrine organ, the thyroid
is an essential biochemical factory; it produces hormones.
In particular, it produces two related hormones called
triiodothyronine (T3), and thyroxine (T4). There is a
constant requirement for these two hormones because they
help to control the activity of multiple organs, such
as the heart, the liver and the pancreas, as well as the
rate of synthesis of muscle proteins. The overall effects
of the thyroid hormones are expressed in terms of oxygen
consumption, or basal metabolic rate.
These two hormones,
T3 and T4, possessing very simple structures composed
from the amino acid tyrosine as well as the element iodine;
this is the same element that can be found in a commercially
available antiseptic known as Betadine. When both tyrosine
and iodine are available, the thyroid utilizes enzymes
that combine tyrosine and iodine, synthesizing the T3
and T4 hormones in the process and eventually storing
them in the form of colloids. When the demand for circulating
hormones increases, T3 and T4 are released from storage.
Of
course, resembling everything else in the human body,
the thyroid is prone to functional disorders. The most
common disorder is hypothyroidism, which refers to an
inactive thyroid and/or insufficient thyroid hormones
in circulation. Another less common disorder is goitre,
which is an abnormal bulge in the neck. The main cause
of goitre is iodine deficiency. Since the thyroid is not
getting enough iodine, it increases its surface area by
expanding, all in an attempt to absorb as much iodine
as possible from its surroundings. Leading sources of
dietary iodine are seafood and sea salt. As a consequence,
it is not unusual that this condition is frequently found
in inland areas that are far from the coast. This problem
has been alleviated by artificially adding potassium iodide
(KI) to table salt, which can be easily purchased at supermarkets
as ‘iodised salt’. This preventative measure has been
most spectacularly demonstrated in India, where seafood
is rarely on the main menu. By adding KI to table salt,
India managed to drastically reduce the incidence of goitre.
Recently,
however, there has been a small rise in the incidence
of goitre in the Western world. This is attributed to
the low-salt diet preferred by overcautious salt consumers.
Due to publicity surrounding studies that suggest that
high-salt diets cause hypertension (high blood pressure)
and increase the risk of heart attacks, many people have
chosen to reduce their levels of salt consumption. The
amount of iodine intake correlates with the amount of
salt intake, which means that reduced salt intake will
lead to a decreased iodine intake. While preventing hypertension
is a positive measure, it also seems to raise the danger
of contracting goitre. What is necessary is a balance
between too much salt and too little salt intake; in other
words, everything good should be done in moderation. Similarly
this principle of moderation appears applicable to many
the other kinds of food, minerals, and vitamins that one
consumes. Now, who ever said salt is bad for you?
Further Reading
http://www.nlm.nih.gov/medlineplus/thyroiddiseases.html
http://www.altsupportthyroid.org/t3.php
http://www.planetherbs.com/articles/thyroid.html
http://www.biopsychiatry.com/thyroid.htm
http://www.showfeedsinc.com/educational4.htm
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