The Danger of Tiny Doses

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From the book " The Autoimmune Epidemic " ...join the discussion group at

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A must read for everyone you know.

page 54

" The Danger of Tiny Doses "

" Dioxin, along with pesticides, insecticides, and plasticizers such as

bisphenol A, or BPA, a plastic building block used in everything from safety

helmets, dental sealants, and eyeglass lenses to everyday food packaging, are

what are also known as endocrine disruptors, a group of environmental

contaminants that can affect our immune system and our resistance to disease in

another particularly insidious way-and in particularly small doses-by disrupting

our bodies' natural hormone signals.

Animals and humans secrete minuscule amounts of hormones, such as estrogen,

that trigger responses when they occupy special receptors made to receive them

on the cells of various organs in our bodies. These hormones are secreted into

the blood by the endocrine glands that produce them-the thyroid, pancreas, and

adrenals glands, as well as the ovaries and testes-in response to signals from

the brain. Chemicals like PCBs, plastic additives such as BPA, and common

pesticides are among the numerous chemicals that, upon entering our bloodstreams

through daily exposure, can mimic estrogen by occupying our cells' estrogen

receptors.

You might think of estrogen being secreted in the body as something akin to a

radio signal thaty's being sent out from a station, and its receptor-a protein

on the surface of a cell elsewhere in the body-as the antenna. The proper

signal has to reach the antenna in order for the signal to be received-and for

music, rather than static, to come out of the radio. When endocrine disruptors

mimic real estrogen they can wreak havoc in one of two ways: first, they can

block the estrogen receptor site altogether, keeping our natural estrogen from

triggering the responses it's supposed to so that it can do its normal job in

the body. When estrogen signals are blocked, it prevents our hormones from

sending out any signel at all. The second way endocrine disruptors work is not

by blocking communication completely, but by sending the wrong signals between

cells.

Researchers now understand that a wide array of environmental chemicals can

act as endocrine disruptors, affecting us at much lower doses than scientists

previously thought possible. A growing body of new science on low-dose

exposures suggests to investigators that even minute traces of many common

chemicals-at levels that have been touted by industry and some scientists to be

biologically safe-can affect our cell activity by sending out artificial

messages to the body through our endocrine system.

Endocrine-disrupting chemicals are remarkable adept at traveling through the

bloodstream and entering our cells by tricking specific receptors on cells into

believing that the chemicals are, in fact, real estrogen being secreted by our

own bodies( endocrine literally means " secreting internally " ). Once in the

cell, these chemical imposters bind with estrogen receptors and begin to set

things askew by sending out false signal to the rest of the body-one that the

brain did not intend or command. It is as if the radio waves have been hijacked

by a rogue station. Suddenly, instead of musci emerging from the radio, these

imposters send out scrambled signals-a completely different kind of sound. The

cells in the body begin to respond inappropriately, acting as if they've been

signaled by real estrogen to cause other cellular interaction to take place whrn

in fact these exchanges are not what the body intended at all. The cells begin

to dance to the wrong tune-engaging in

precarious missteps.

When this normal cellular interaction begins to go haywire at major phases of

development-say, when Becky's son Zachary was developing in her womb, or while

his infant brain is maturing, or in eight or so years when Selena comes into

puberty-these artifical chemicals usurping the place of natural estrogen can

trigger unnatural responses. Scientists have worried for decades about data

showing endocrine disruptors' effects on the brain and the reproductive system.

As we learn more about how these chemicals interfere with cellular signaling in

the body, endocrine mimikers have become a grave concern to scientists studying

autoimmune disease. "

to be continued....