Iodine Deficiency and Cancer

Tip #22: Iodine deficiency and breast cancer

Iodine is a chemical element. The body needs iodine but cannot make it. The needed iodine must come from the diet. As a rule, there is very little iodine in food, unless it has been added during processing, which is now the case with salt. Taking iodine supplements, including iodized salt, is effective for preventing and treating iodine deficiencies.
Source: WebMD


Iodine Deficiency and Cancer, a Closer Look

A deficiency of iodine has been found to influence the occurrence of many cancers. In Turkey (the country), gastric cancers are most common in areas where iodine deficiency is high. Increased iodine intake over the past several years has been strongly correlated with a reduction in stomach cancers.

Researchers have attributed the low rate of breast cancer in Japan to high dietary iodine (and selenium). Breast cancer cells need iodine to facilitate cell death and suppress tumor growth.
Source: The Truth About Cancer


This study states: For several decades, research suggests that some breast diseases may be considered iodine deficiency diseases. Evidence supporting this hypothesis include: 1) iodine-rich seaweed exhibits an anti-cancer effect on breast cancer cells and on animal model; 2) adding seaweed to rats’ food delays the onset and number of rat mammary tumors; 3) for women experiencing painful breasts with fibrocystic disease, iodine improved symptoms ; and 4) iodine consumption by Americans has dropped 50% since the 1970s as breast cancer rates have risen. By contrast, Japanese women consume 25 times more dietary iodine than North American women and have lower breast cancer rates.

However, the increased incidences of both breast cancer and thyroid cancer since the use of iodized salt became mandated have raised some concerns challenging this consensus.


This study concluded:
dietary iodine insufficiency represents a plausible explanation for the increasing incidence of breast cancer in young women with distant metastasis. In view of the established reduction in iodine levels in US women of childbearing age since the mid 70s, this group would be most vulnerable to increased breast cancer risk.


This letter, published in the Journal of Cancer says:
Iodine deficiency has been proposed to play a causative role in the development of breast cancer. Dietary iodine has also been previously proposed to play a protective role in breast cancer, to a large degree based on the increased iodine consumption of dietary iodine in Japanese women, having and exceptionally low incidence of breast cancer. Furthermore, emigration of Japanese women  and adopting a western diet is associated with higher breast cancer rates. Iodine is taken up by the sodium/iodide symporter in the breast and its role is important in promoting the development of normal versus neoplastic breast tissue development.

What foods provide iodine?

Iodine is found naturally in some foods and is also added to salt that is labeled as ”iodized”. You can get recommended amounts of iodine by eating a variety of foods, including the following:

  • Fish (such as cod and tuna), seaweed, shrimp, and other seafood, which are generally rich in iodine.
  • Dairy products (such as milk, yogurt, and cheese) and products made from grains (like breads and cereals), which are the major sources of iodine in American diets.
  • Fruits and vegetables, which contain iodine, although the amount depends on the iodine in the soil where they grew and in any fertilizer that was used.
  • Iodized salt, which is readily available in the United States and many other countries. Processed foods, however, such as canned soups, almost never contain iodized salt.

What kinds of iodine dietary supplements are available?

Iodine is available in dietary supplements, usually in the form of potassium iodide or sodium iodide. Many multivitamin-mineral supplements contain iodine. Dietary supplements of iodine-containing kelp (a seaweed) are also available.
Source: Office of Dietary Supplements


Iodine is available in a seaweed powder form.
Wakame and Mekabu are the stem and leaves of Undaria seaweed, which is treasured more than any other type of seaweed for its unique phytonutrients. These sea vegetables produce chemicals called fucoidans that protect them from their harsh marine environment and are an important part of the famed Okinawan longevity diet. They are also a rich source of the key trace mineral iodine, which is vital for thyroid health. Source: plantbased.nz

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