Sunday 8 January 2012

World's Healthiest Foods Highlights American's Risk of Iodine Deficiency- Essential Nutrient and Key to BioLargo Technology

The World's Healthiest Foods

Americans at High Risk for Iodine Deficiency: Sea Vegetables a Reliable Source

Research published in Environmental Science and Technology, (Dasgupta P, Liu Y, et al.) has revealed that iodized salt is not likely to contain the amount of iodine it's supposed to, and even if it did, many Americans are cutting back on salting home-cooked meals.

Because excessive sodium intake can increase hypertension risks, many agencies now recommend reducing salt intake. A 1995 report found 58% of men and 68% of women reported never using salt, using "lite" salt, or rarely using ordinary table salt.

In addition, the use of iodized salt is not mandatory in the U.S., and virtually all of the salt used in restaurants and processed foods in the U.S. is not iodized, leaving Americans at high risk for iodine deficiency.

Although product labels state that U.S. iodized salt contains 45 µg of iodine per gram, when University of Texas researchers analyzed 88 samples of iodized table salt from 40 states, 53% of samples contained less. Iodine values in freshly opened, top-of-the can samples ranged from as little as 12.7 to 129 μg/kg. And the amount of iodine within each can was not homogenous but varied as much as 3.3 times among the 5 samples taken at different depths from the same container. In addition, iodine was also found to decrease greatly during high humidity storage, although light or heat had little effect.

In sum, even if you don't eat out a lot and are using iodized salt, you have no idea how much iodine it is actually providing, and the longer you've had that container of salt, the more likely its iodine content has decreased.

Why should we be concerned? Iodine is necessary for the body's production of thyroid hormones, which, in addition to regulating metabolic rate, direct brain development, making iodine critical starting in the first trimester of pregnancy through adolescence.

Lack of sufficient iodine is the leading cause of preventable mental retardation in the world. Even a mild iodine deficit in pregnant women, infants, and children, can lower intelligence by 10-15 IQ points, lessening an individual's mental abilities throughout life.

Public-health studies over the past 30 years indicate that iodine levels in the U.S. population, particularly in women of childbearing age, are too low. Urinary iodine (the standard means of evaluating iodine levels in the body) has plummeted by almost 50% in adults, and the frequency of moderate iodine deficiency (urinary iodine excretion of less the 50 μg per liter) in pregnant women has jumped from 1% to 7%.

In an editorial in the New England Journal of Medicine entitled "Iodine Nutrition - More is Better," thyroidologist Robert Utiger of Harvard Medical School urges that the recommended daily intake of iodine be increased to 300 to 400 μg.

Practical Tip: Kelp, dulse, hijiki, and nori, can be relied upon as an excellent source of iodine (a mere ¼ cup supplies 415μg). To ensure you are getting enough iodine, make sea vegetables a staple in your healthy way of eating.

One important caveat: Purchase only certified organic sea vegetables to ensure they are free of contamination. Sea vegetables have a high affinity for heavy metals, and if grown in polluted waters, can soak up not only healthful minerals, but also contaminants such as arsenic, lead, cadmium or mercury. (van Netten C, Hoption Cann SA, et al. Sci Total Environ)

Dasgupta P, Liu Y, Dyke J. Iodine nutrition: iodine content of iodized salt in the United States. Environ. Sci. Technol., 42 (4), 1315-1323, 2008.

Utiger RD, N Engl J Med. 2006 Jun 29;354(26):2819-21, PMID: 16807421

van Netten C, Hoption Cann SA, Morley DR, van Netten JP. Elemental and radioactive analysis of commercially available seaweed. Sci Total Environ. 2000 Jun 8;255(1-3):169-75. PMID: 10898404

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