Iodine is one of the most important minerals — your body requires it for healthy cellular and metabolic functioning. A book by Dr. David Brownstein, Iodine: Why You Need It and Why You Can't Live Without It, sums up its importance:

"Iodine is the most misunderstood nutrient. After 12 years of practicing medicine, I can say that it is impossible to achieve your optimal health if you do not have adequate iodine levels. I have yet to see any item that is more important for promoting health than iodine."

If Dr. Brownstein is right — and I agree that iodine deficiency is a major problem — our drop in iodine intakes might be contributing to many major health problems.

Examples? Iodine deficiency might be contributing to the large increase in thyroid problems being seen clinically. Low iodine can contribute to an increased risk of both underactive and overactive thyroid. And iodine-blocking bromides are implicated in many thyroid disorders — one study showed bromides were 50 times higher in the thyroid tissue of people with thyroid cancer.

Iodine plays a key role in breast tissue, and women with breast cancer have lower iodine levels in their breast tissue than women without the disease.

Women in Japan get much more iodine in their diets — and have a 65 percent lower risk of breast cancer than U.S. women.

The effect of iodine on breast tissue is so marked, that hypothyroid women (who can't process the mineral well in the thyroid, thereby freeing up more iodine for use in breast tissue) actually have lower levels of breast cancer.

Lower levels of iodine may also increase the risk of heart disease. For a review of this issue, see “Hypothesis: Dietary Iodine Intake in the Etiology of Cardiovascular Disease” in the Journal of the American College of Nutrition.