> Health and Disease > Blood and Glandular Disorders > thyroid disease

Flora, a serene young mother, is troubled by unusual bouts of anxiety and irritability, by shortness of breath and palpitation, and by the fact that, despite eating more than usual, she is losing weight. James, an energetic businessman, has recently felt sluggish and tired. His physical and mental reactions seem slower, and though he eats less than usual, he is gaining weight. In fact, both sets of symptoms are early signs of thyroid disorders.

Thyroid disorders affect one in 20 people and are four to six times more common in women. Thyroid hormones control metabolism and energy production. They regulate the heart rate, blood pressure, body temperature, brain activity, bone health and various other functions. The hormones are made in the thyroid gland with the help of dietary iodine, and are transported into the blood under the command of thyroid stimulating hormone (TSH), which is released from the pituitary gland of the brain. When blood samples show a high level of TSH and low levels of thyroid hormones, the diagnosis is an underactive thyroid condition. If tests show low TSH and high thyroid hormone levels, the patient has an overactive thyroid.

Hypothyroidism

An underactive thyroid, or hypothyroidism, occurs when the thyroid gland stops producing enough thyroid hormones. In some developing countries, a lack of iodine is the main cause for an underactive thyroid, but in developed countries this is rare. Other causes may be insufficient TSH, which controls thyroid hormone production, or a lack of response of cells to thyroid hormones, so that even though there are normal levels of thyroid hormone levels in the blood, the outcome is as if the hormones were not there.

Symptoms vary, depending on the severity of the condition. Sluggishness, chills and digestive problems are most common. Other signs include a slow metabolic rate, weight gain, joint stiffness, painful premenstrual periods, muscle weakness, dry skin, coarse and brittle hair, recurrent infections and depression.

About three per cent of women of childbearing age may develop a mild underactive thyroid condition that can go undetected for lack of physical symptoms. It is important to monitor thyroid health because an underactive thyroid during pregnancy may have consequences to the unborn child.

Conventional medical treatment for an underactive thyroid is thyroid replacement therapy, for example using levothyroxine. Thyroid malfunction from other causes is treated accordingly under medical supervision. Most diseases of the thyroid are treated successfully.

Dietary Factors

Adequate iodine and an overall nutrient-rich diet can help prevent hypo- thyroidism. Good sources for iodine are iodized salt, seafood, cabbage and kale. Kelp is a seaweed particularly rich in iodine and available in over-the-counter supplements. The amounts of iodine needed are very small: 150 micrograms for adults, 200 mcg for pregnant women, 50 mcg for children ages one to six, and 90 mcg for ages seven to 12.

Goitrogens are substances that interfere with iodine metabolism in the thyroid gland. Goitrogen-containing foods include turnips, cabbage, cauliflower, peanuts, soy beans, brussels sprouts, kale, millet, mustard greens, spinach and broccoli. The enzymes required for the production of goitrogens in these plants are destroyed by cooking, and moreover, some of these plant foods, such as the cruciferae family contain iodine and are beneficial in the prevention of cancer. Thus, scientists recommend against limiting the consumption of these vegetables and making sure that your iodine intake from various sources is adequate.

Recent studies show that selenium, found in seafood and brewer’s yeast, is an important mineral for a healthy thyroid. A selenium deficiency may lead to an underactive thyroid.

Vitamin A is important for healthy thyroid function. Animal studies show that a lack of adequate vitamin A can increase the risk of an underactive thyroid condition. Take as directed.

Hyperthyroidism

Carmia Borek, a research professor at Tufts University School of Medicine in Boston, is the author of Maximize our Healthspan With Antioxidants: The Baby Boomer’s Guide (Keats Publishing, 1995)

Source: alive #233, March 2002