Iodine is Important but a New Study Shows Too Much Causes Problems
February 08, 2012
By Dr. Mercola
Iodine is a vitally important nutrient that is detected in every organ and tissue. Along with being essential for healthy thyroid function and efficient metabolism, there is increasing evidence that low iodine is related to numerous diseases, including cancer.
Worldwide, it's thought that up to 40 percent of the population is at risk of iodine deficiency.
In the United States, health agencies tend to say most people are iodine "sufficient," meaning they get enough of the nutrient from their diet, however this is controversial.
According to other sources, such as Dr. David Brownstein, who has been working with iodine for the last two decades, over 95 percent of the patients in his clinic are iodine deficient.
There are serious risks to taking too much iodine, however, which is why you need to be very cautious and get informed before opting for an iodine supplement.
Too Much Iodine May Lead to Subclinical Hypothyroidism
Hypothyroidism occurs when your thyroid produces too little thyroid hormone, a condition that is often linked to iodine deficiency. Ironically, new research has shown that taking too much iodine may also lead to a subclinical version of the condition, which is a milder form that is often missed by laboratory tests. Along with sometimes exhibiting many of the same symptoms of hypothyroidism, such as fatigue and difficulty losing weight, people with subclinical hypothyroidism may have an increased risk of heart disease.
Some, however, may exhibit no symptoms at all.
The new study, published in the American Journal of Clinical Nutrition, revealed that study participants taking relatively higher doses of supplemental iodine -- 400 micrograms a day and more – paradoxically began developing subclinical hypothyroidism. The finding highlights precisely why you need to be very careful with taking supplemental iodine, as taking too much can lead to health problems.
In fact, I don't generally advise taking iodine supplements like Lugol's or Ioderol, because your thyroid only transports iodine in its ionized form (i.e. iodide). Your thyroid reduces iodide (I-) into iodine (I2) for use in formation of thyroglobulin. Your body doesn't utilize iodine directly. It has to split the I2 into two I- ions, which is an oxidative reaction that causes oxidative stress.
I recommend taking an iodine supplement in the event of some type of nuclear fallout. In this case, if you're iodine deficient taking a potassium iodide (a stable form of iodine) supplement can protect your thyroid by "flooding" your system with iodine so your thyroid has no need to take in the radioactive form. But taking potassium iodide when it is not absolutely necessary could result in thyrotoxicosis. In most cases it is far preferable to optimize your iodine through the natural intake of foods.
Why Might Your Iodine Levels be Low?
More than 11 percent of all Americans—and more than 15 percent of American women of child-bearing age—presently have urine iodine levels less than 50 mcg/L, indicating moderate to severe iodine deficiency.i An additional 36 percent of reproductive-aged women in the U.S. are considered mildly iodine deficient (<100 mcg/L urinary iodine). Iodine levels have significantly dropped in the United States in recent decades due to several factors, including:
- Bromine exposure: When you ingest or absorb bromine (found in baked goods, plastics, soft drinks, medications, pesticides and more), it displaces iodine, and this iodine deficiency leads to an increased risk for cancer of the breast, thyroid gland, ovary and prostate -- cancers that we see at alarmingly high rates today.
- Declining consumption of iodine-rich foods, such as iodized salt, eggs, fish, and sea vegetables
- Soil depletion
- Less use of iodide in the food and agricultural industry
- Fluoridated drinking water
- Rocket fuel (perchlorate) contamination in food
What's this doing to our country's health? The Japanese consume 89 times more iodine than Americans due to their daily consumption of sea vegetables, and they have reduced rates of many chronic diseases, including the lowest rates of cancer in the world. The RDA for iodine in the U.S. is a meager 150 mcg/day, which pales in comparison with the average daily intake of 13800 mcg/day for the Japanese.
There is a large body of evidence suggesting that low cancer rates in Japan are a result of their substantially higher iodine levels, as iodine has documented antioxidant and anti-proliferative properties.
If you are interested in being tested for iodine deficiency, ask your health care provider about the urine iodine challenge test. Another simple way to ensure you're getting enough iodine is to get an inexpensive prescription from your physician for SSKI, which is a super-saturated potassium iodine. You simply apply three drops to your skin and rub it in, once a day. If when you touch something with slightly wet fingertips it leaves a yellowish stain, then the iodine is coming out of your skin, indicating your body is saturated, i.e. you're getting enough iodine.
The Best Natural Sources of Iodine
If you want to optimize your iodine levels naturally, pay careful attention to your diet. I believe that toxin-free sea vegetables and spirulina are likely the ideal way to obtain your iodine—however, make sure that these are harvested from uncontaminated waters. Raw milk and eggs contain iodine, as well. At the same time, you'll want to avoid all sources of bromine as much as possible, as this appears to play a large role in the rising levels of iodine deficiency. Here are several strategies you can use to avoid bromine and thereby help optimize your iodine levels naturally:
- Eat organic as often as possible. Wash all produce thoroughly. This will minimize your pesticide exposure.
- Avoid eating or drinking from (or storing food and water in) plastic containers. Use glass and safe ceramic vessels.
- Look for organic whole-grain breads and flour. Grind you own grain, if possible. Look for the "no bromine" or "bromine-free" label on commercial baked goods.
- Avoid sodas. Drink natural, filtered water instead.
- If you own a hot tub, look into an ozone purification system. Such systems make it possible to keep the water clean with minimal chemical treatments.
- Look for personal care products that are as chemical-free as possible. Remember -- anything going on you, goes in you.
- When in a car or a building, open windows as often as possible, preferably on opposing sides of the space for cross ventilation. Utilize fans to circulate the air. Chemical pollutants are in much higher concentrations inside buildings (and cars) than outside.