Goitrogens - the plant thyroid toxins

Goitrogens - the plant thyroid toxins

Thyroid Toxins: The Double-Edged Swords of the Kingdom Plantae

By Chris Masterjohn

Abstract
Plants produce many toxic substances to defend themselves from insects
and other herbivores. Because some of these may be healthful to humans
in small amounts by helping to rev up our defenses against toxins, it
is important to rely on human epidemiological evidence and
experimentation using whole foods in live animals rather than test
tube science. Such research has indicted several classes of foods that
may exert a toxic effect on the thyroid gland and thyroid hormone
metabolism in humans; we call these foods goitrogenic and we call the
chemicals responsible for this effect goitrogens. Goitrogenic foods
include soy, millet, cruciferous vegetables, cassava, lima beans, flax
seeds, almonds, and fruits and fruit seeds of the Rosacea family.
Millet flavonoids are more dangerous than others.

Cooking and fermenting do not destroy millet or soy goitrogens; in
fact, they make these foods more goitrogenic. Millet goigrogens are
present in both the bran and the endosperm. Traditionally prepared
millet that is dehulled, fermented and cooked into a porridge is
associated with goiter in humans. Microwaving crucifers reduces the
average isothiocyante yield to one-half; steaming them reduces this
yield to one-third; boiling them for a half hour and dumping out the
water almost entirely eliminates this yield. The effect of microwaving
and steaming is dependent on the individual's intestinal flora and is
thus highly variable, whereas the efect of boiling is more reliable
and constant. Fermentation makes crucifers more goitrogenic. The most
effective way of removing cyanogenic glycosides is by crushing the
tubers and leaching them in running water for several days, and by
blanching and boiling the leaves. Dietary iodine is able to overcome
the effect of cyanogenic glycosides, moderate amounts of crucifers,
and is probably able to overcome the effect of soy flavonoids. It is
not able to overcome large amounts of crucifers or any amount of
millet.

People who have resilient health while eating these foods should
continue to eat them with impunity. However, people who have thyroid
problems or other problems associated with iodine deficiency or
cyanide exposure should consider experimenting with the following
dietary restrictions: 1) eliminate millet; 2) moderate soy and only
consume it with additional sources of iodine; 3) limit crucifer intake
to five servings per week, only eat more than this if ti is boiled,
and match one's crucifer intake with extra iodine; 4)avoid foods with
cyanogenic glycosides unless they are extensively boiled or crushed
and leached in running water for several days, and match one's
cyanogen intake with extra iodine and vitamin B12-containing foods or
supplements (but not cyanocobalamin). These foods are not inherently
unhealthy but simply contain chemicals that have the capacity to hamr
the health of some people under some circumstances; this is true of
all foods. Experience always trumps theory, so the individual should
use this information as but one tool with which she or he can
experiment to find the most appropriate diet for herself or himself.

SOURCE: http :// www .cholesterol-and-health,com /Goitrogen-Special-Report.html