By Henrylito D. Tacio
The thyroid gland is a butterfly-shaped organ that measures about two inches across and lies just under the skin below the Adam’s apple in the neck. It plays a major role in regulating the body’s metabolism. According to the National Nutrition Survey in 2013, about 5.8 million Filipinos were afflicted with thyroid disorders in different clinical presentations, including goiter, thyroid malignancy, mental deficiency, physical deformities, congenital hypothyroidism, cretinism, and reproductive failure. These disorders could lead to the detrimental reduction of intellectual and physical capacity and even death among susceptible individuals, in untreated, warns the local health department.
Among the thyroid disorders, goiter – locally known as bosyo – is the most common with a prevalence rate of 10.12%.
“[The primary symptoms of goiter] are thyroid enlargement, breathing difficulties, swallowing difficulties from compression of the esophagus, and neck vein distention and dizziness when the arms are raised above the head,” says Dr. Gabriel Jasul, Jr., director of the Philippine Society of Endocrinology and Metabolism.
The word goiter comes from the Latin word guttur, which means “throat.” Having goiter doesn’t necessarily mean that the amount of thyroid hormone in your body is too high, or too low. It just means that the gland is bigger than it should be, and that there may be a disease process going on.
Common among women
“Goiter is considered prevalent in the Philippines,” says Dr. Jasul. “It is common and is still a formidable disease that affects women under reproductive age and school children aged seven years old onwards. Pregnant women and children are prone to goiter, as they undergo hormonal changes. Iodine deficiency during pregnancy may result in decreased secretion of thyroid hormone by the mother and fetus.
Based on the studies on urinary iodine levels conducted by the Department of Health, most goiter cases are found in the mountainous provinces and other remote areas of the country. Those living in the lowland areas may have goiter because of insufficient iodine intake in their diet aside from eating a lot of foods containing goitrogens, substances that suppress the function of the thyroid gland by interfering with iodine uptake. Goitrogens may be found in cabbage, soybeans, peanuts, peaches, strawberries, spinach, and radishes.
Iodine deficiency
Iodine is a micronutrient required by the body for normal physical and mental development. The total lifetime requirement for iodine amounts to no more than a teaspoon. However, to be effective, this amount must be available from conception to adulthood.
Despite the miniscule requirement, studies have shown that iodine deficiency is the cause of 92% of all goiter cases around the world. A nutritional survey done among 10,616 school children aged six to 12 years by the Philippine Food and Nutrition Research Institute in 1998, demonstrated findings of widespread mild iodine deficiency nationwide.
“When iodine is deficient,” states The Merck Manual of Medical Information, “the thyroid gland enlarges, forming a goiter, as it attempts to capture more iodine for the production of thyroid hormones.”
The American Thyroid Organization explains further: “The primary activity of the thyroid gland is to concentrate iodine from the blood to make thyroid hormone. The gland cannot make enough thyroid hormone if it does not have enough iodine. Therefore, with iodine deficiency, the individual will become hypothyroid.
“Consequently, the pituitary gland in the brain senses the thyroid hormone level is too low, and sends a signal to the thyroid [in the form of] the thyroid stimulating hormone (TSH). As the name implies, this hormone stimulates the thyroid to produce thyroid hormone and to grow in size. This abnormal growth in size produces what is termed a goiter.”
Other causes
Another common cause of goiter is Graves’ disease. In this case, a person’s immune system produces a protein, called thyroid stimulating immunoglobulin (TSI), which stimulates the thyroid gland to enlarge, producing a goiter. However, TSI also stimulates the thyroid to make too much thyroid hormones, causing hyperthyroidism. Since the pituitary senses too much thyroid hormone, it stops secreting TSH. In spite of this, the thyroid gland continues to grow and produce thyroid hormones. Therefore, Graves’ disease produces a goiter and hyperthyroidism.
Another cause is Hashimoto’s thyroiditis, an autoimmune condition in which there is destruction of the thyroid gland by a person’s own immune system. “As the gland becomes more damaged, it is less able to make adequate supplies of thyroid hormones,” the American Thyroid Organization explains. “The pituitary gland senses a low thyroid hormone level, and secretes more TSH to stimulate the thyroid. This stimulation causes the thyroid to grow, which may produce a goiter.”
In addition to the common causes of goiter, there are many other less common causes. Some of these are due to genetic defects, others are related to injury or infections in the thyroid and some are due to tumors (both cancerous and benign tumors).
Iodized salt
Thanks to the introduction of iodized salt in the 1920s, goiters have become much less common in North America than they once were. “Salt is the best vehicle for adding iodine,” states a fact sheet disseminated by the health department. Everyone needs salt, everyone eats it, usually in daily amounts, and the technology for iodization is straightforward.”
The Philippines has regulations calling for 20-40 microgram (mcg) iodine per gram of salt – or 20-40 parts per million (ppm). As such, if a person eats five grams of salt iodized at 30 ppm, he gets 150 mcg iodine from this source alone.
Another method for providing iodine is through the administration of iodized vegetable oil. A single administration orally provides adequate iodine for about a year, and if given by intramuscular injection, is satisfactory for about three years. “Iodized oil is most useful when the iodine deficiency is severe, when immediate correction is important, and when iodized salt is not available (or its iodine concentration is below recommended levels),” the fact sheet points out.
Drinking water is another occasional vehicle for iodine nutrition. One approach is to add an iodine solution to water in a well or flowing through a pipe. A simpler version merely adds a few drops of a concentrated solution manually to vessels containing drinking water in a school or home. If iodine is added, it can also sterilize the water, this property is useful because many regions with iodine deficiency also have contaminated food and water.
“The use of iodized table salt prevents hypothyroidism, while limiting goitrogenic foods and drugs prevents hyperthyroidism,” says Dr. Jasul. “We don’t say that you should not eat goitrogenic foods, especially vegetables. Goitrogenic foods help thyroid hormones to function normally, but to achieve this purpose, the thyroid hormones must be present in the body in the correct amount – not too little and not too much.”
Forewarned
Forewarned is forearmed, so goes a saying. The same is true with goiter. Watch what you eat. “To cut the risk of goiters, avoid white flour products, white sugar, foods from flesh, fried foods, greasy foods, preserves, condiments, tea, coffee and alcohol. You will also want to avoid sodas or anything with caffeine,” writes Eric Benac, author of Diet for Goiter.
Foods you need to eat: “Begin introducing foods rich in iron and iodine into your diet,” Benac writes. “Foods like guavas, strawberries, citrus fruits, eggs, seafood, whole grain rice, tomatoes, oats, onion, garlic, carrots and lettuce are high in iron. Foods that are high in iodine include iodized salt, seafood, seaweed, sushi, shrimp, shellfish, cow’s milk, yogurt, and locally grown fruits and vegetables. These foods, along with goiter treatment medicine from your doctor, will help treat your goiter in a short period of time.” – ###
