Reducing Salt Intake Won’t Make you Iodine Deficient, from the Harvard Heart Letter

BOSTON—The surplus of sodium in the American diet contributes to a host of cardiovascular problems, from high blood pressure and stroke to heart attack, heart failure, and more. Cutting back on salt is generally good for the heart and arteries. But some people fear that by doing this they won't get enough iodine in their diets. Not to worry, explains the June 2011 issue of the Harvard Heart Letter. Salt provides only a fraction of daily iodine intake for most Americans.

The human body needs iodine to make thyroid hormone. This hormone is critically important during fetal development, infancy, and childhood, for the brain and nervous system to develop normally. Later in life, thyroid hormone controls metabolism. Adults who don't take in enough iodine can develop a goiter (a swelling of the butterfly-shaped thyroid gland in the neck), and the low output of thyroid hormone can lead to sluggish metabolism, poor thinking skills, infertility, thyroid cancer, and other conditions. Since the 1920s, iodized salt has been one way of preventing iodine deficiency.

Current dietary guidelines recommend that men and women aged 19 years and older get 150 micrograms of iodine a day. Women who are pregnant should get 220 micrograms, and women who are breast feeding an infant should get 290 micrograms.

Most of the sodium in the American diet comes from prepared or processed food, and most food companies don't use iodized salt. This is a great place to start trimming sodium from your diet, and it will have little effect on your iodine intake. It makes more sense to get your iodine from food. That way you can cut back on salt and not worry about losing out on this important element. Ocean-caught or ocean-farmed fish and shellfish tend to be naturally rich in iodine. Other good sources include milk, cheese, yogurt, eggs, and vegetables grown in iodine-rich soil. Multivitamin pills that also contain minerals usually provide 150 micrograms of iodine.

Read the full-length article: “Cut salt - it won't affect your iodine intake”

Also in this issue:

- Specialized care improves stroke survival

- Weight-loss surgery can help - and harm - the heart

- Who needs an implantable cardioverter-defibrillator?

The Harvard Heart Letter is available from Harvard Health Publications, the publishing division of Harvard Medical School, for $29 per year. Subscribe at www.health.harvard.edu/heart or by calling 877-649-9457 (toll-free).

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