Iodine: Mammary Gland Gatekeeper? (for breast cancer survivors)

Iodine: Mammary Gland Gatekeeper? (for breast cancer survivors)

The title of this section is based on a 2005 article, “Is Iodine a Gatekeeper of the
Integrity of the Mammary Gland?” (Aceves, Anguiano, and Delgado), in which a
strong case is made for the role of iodine in “contributing to the integrity of the
normal mammary gland” through its function as both an antioxidant and an
antiproliferative agent. In fact, Dr. David Brownstein, author of Iodine: Why You
Need It, Why You Can’t Live Without It, goes so far as to state:

The chance of a woman having invasive breast cancer sometime during
her life is now one in seven. The single most important nutrient to halt this
progression is iodine. In fact inadequate breast iodine levels have been
associated with the development of breast cancer in both animals and
humans, while iodine supplementation has been shown to cause cancer
cells to shift into apoptosis or programmed cell death. I have no doubt one
of the reasons we are seeing such an epidemic of breast cancer is due to
iodine deficiency. (pers. comm.)

There’s a wealth of data to back him up. For example, in Japan, where the
population consumes approximately 14 milligrams of iodine daily from seaweed,
women have one of the lowest breast cancer rates in the world (Kawamura and
Sobue 2005).

Investigators observed the same phenomenon experimentally in rats, when the
animals were given a potent carcinogen and then some were treated with various
forms of iodine and thyroid hormone. The researchers found that the rats that
received the treatment experienced almost 41 percent fewer tumors (Aceves,
Anguiano, and Delgado 2005). This is a big difference!
Human studies identifying the connection between iodine deficiency and breast
tumors actually date back over forty years (Eskin et al. 1967), but have been slow to
come to the attention of the public. One did recently, however. Two groups of breast
cancer patients were studied who had undergone biopsy but not had surgery yet. One
group was given iodine and the other a placebo. Next, breast tissue was analyzed and
compared after surgery. Results showed that “although tumor size did not differ
between groups, a significantly lower proliferation and increased apoptotic rate
[cell death] were observed in tumors from women supplemented with iodine”
(Vega-Riveroll et al. 2008).

What happened exactly? In a nutshell:

• Tumor cells replicated more slowly.
• Tumor cells died more quickly.
• The growth factor known as VEGF (vascular endothelial growth factor) was diminished.

• Blood vessels grown expressly to “feed” the tumor in a process known as angiogenesis were fewer in number.

Interestingly, iodine levels began to fall precipitously in the United States in the
1970s, as breast cancer rates began to rise. In fact, iodine levels declined a full 50
percent between 1971 and 2000 (Caldwell et al. 2008). This drop began in earnest
when bakers started substituting bromide for potassium iodate (a form of iodine) as
a dough conditioner in baking; some manufacturers added bromide to sodas; and
others used bromide in medications, flame retardants, pesticides, or some
combination of these compounds. Since bromide competes with iodine for
absorption (as do the elements fluoride and chorine), it’s easy to become deficient
in iodine when our bodies are saturated with bromide, fluoride, and chlorine from
food, water, and personal care products on a daily basis.