The incidence of breast cancer in North America has been decreasing since 2000 but it is still the second-most common cancer in women next to lung cancer.
Approximately one in eight American women will develop breast cancer during their lifetimes. (1) While the U.S. and Canada represent only five percent of the world’s population, new breast cancer cases in these countries account for fifteen percent globally on an annual basis. (2)
Worldwide, the numbers of women diagnosed with breast cancer is increasing in developing countries. (3) Risk factors include:
- hormone imbalance
- diet and lifestyle
- certain medications
- exposure to radiation (X-rays)
- heavy alcohol consumption
- some personal care products
- exposure to environmental chemicals
- early menstruation, late childbirth, and late menopause (4)
- mammograms (yes, you read that right)
The Impact of Iodine on Breast Cancer Risk
Studies have found that Japanese women have a significantly lower risk of breast cancer than Caucasian women. (5,6)
“In general, 1 out of 8 women in the U.S. will be diagnosed with breast cancer in their lifetime. In Japan, that is 1 out of every 38, but it was even less a decade ago,” says Kazuki Takabe, MD, Clinical Chief of Breast Surgery at Roswell Park Comprehensive Cancer Center. (7)
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This corroborates the extensive research by Bernard Eskin, MD, a renowned scientist and member of the faculty at Drexel University College of Medicine in Philadelphia. As early as the 1960s, Eskin found a correlation between iodine deficiency and the risk of breast cancer.
Iodine is an element found in Earth’s crust and is present in foods we eat. It is essential for proper thyroid and endocrine function and is actively involved in the development and health of breast tissue. Iodine deficiency often manifests in the formation of a goiter, when the thyroid tries to retain as much iodine as it can and thereby swells.
We sometimes forget that breasts are not just sweater pillows but are important glands (especially for women) that are part of the body’s endocrine system.
Breast tissues transport molecular iodine and it’s as important to the breasts as it is to the thyroid. (8) Indeed, there is a link between thyroid disorders and breast cancer; iodine deficiency may be the reason why. (9)
Iodine is essential for the development of healthy breast tissue during puberty. (10) It is an important nutrient for the cognitive development of fetuses and infants; the breasts contain iodine so it can be passed to infants from their mothers’ milk. It then follows that inadequate iodine is linked to the development of cancer in breast tissue.
“Ultimately, the etiology of all cancers is multifactorial with benefit assumed in the reduction of modifiable risk factors. There is substantial evidence that iodine deficiency is a modifiable risk factor in cancers of the stomach and breast.” (11)
Dr. Eskin found that iodine-deficient breast tissue is more susceptible to lesions and the formation of cancerous cells earlier and in greater amounts than tissue with adequate iodine. (12)
Furthermore, iodine inhibits breast cancer cell growth and up-regulates the genes responsible for controlling their expression in the first place. (13)