Dear Dr. Blonz: Do you have information on any problems from drinking hot beverages from a plastic cup? I have been using Rubbermaid plastic bowls as drinking cups and frequently eat hot foods out of them. Is there anything leaching from the plastic that a person should be concerned about?
--B.B., San Diego
Dear B.B.: A number of materials are currently used for food packaging, and there is a potential for concern if a substance migrates from the packaging into the food. Such substances are called incidental food additives, and they are regulated by the Food and Drug Administration. Of course, it would be a problem if the substance were potentially harmful, but the compound might also affect the flavor and acceptability of the food.
Make sure that you use containers only for their intended purpose. Many microwave-safe containers, for example, are not appropriate for other types of heating. And many oven-safe materials are unsafe if used in a microwave. Drinking a hot beverage from a plastic cup should be fine as long as it is a hot-beverage cup. It should state this fact on the package. If you have any questions, you should call the cup manufacturer. There is often a toll-free number on the package. One final point: Containers, particularly those made of plastic, do not have an indefinite life span. They should be replaced if the container begins to crack or change color.
Dear Dr. Blonz: My doctor tells me my thyroid level is low, and he has me taking Synthroid. I prefer natural methods because my body doesn't take easily to medication. Can you suggest some way other than medication to raise my thyroid level?
--M.L., Studio City
Dear M.L.: The thyroid hormones regulate the metabolism in every cell of the body. To release its hormones, the thyroid gland, which sits just below the larynx (voice box) in the throat, requires the mineral iodine and the "stimulating" presence of another hormone, appropriately named thyroid stimulating hormone. Some cases of hypothyroidism (inadequate production of thyroid hormone) can be attributed to an inadequate production of TSH. Your doctor should be able to tell you if this is the case.
Most people take in more dietary iodine than they need, so it is unlikely that iodine is the problem. It wasn't always that way, though. Iodine is plentiful in the ocean but is not well-distributed on land. Foods containing iodine used to be limited to seafoods, crops grown in coastal areas, and dairy or meat products from animals that have grazed on iodine-rich feed.
In the early 1900s, there were vast areas in the middle of the country without a dependable supply of dietary iodine. These regions were nicknamed the "goiter belt" because of the prevalence of one of the symptoms of iodine deficiency: a noticeable bulge in the lower throat area. In 1926, as a public-health measure, the government requested that iodine be added to table salt, a move that drastically reduced the incidence of goiter. That was the first instance in which a nutrient substance was purposefully added to foods. Iodized salt contains 76 micrograms per gram, which means that the RDA for iodine can be met with as little as one-half teaspoon.
Since you live near the ocean, it is doubtful that your diet would lack sources of dietary iodine. If you are not using iodized salt, and you refrain from having any seafood, it may pay to adjust your diet.
There are compounds called goitrogens (GOY-trow-ginz) that have an ability to interfere with the use of iodine by the thyroid gland. These compounds are found in foods such as cabbage, Brussels sprouts, kale, cauliflower, broccoli, kohlrabi and turnips. Goitrogens, however, tend to be inactivated by cooking. So unless you are eating these vegetables raw on a regular basis, it's doubtful that they would be the reason for your problems.
Whatever the cause, it is important that your hypothyroidism be treated. The symptoms of an inadequate production of thyroid hormone include sluggishness, intolerance of cold temperatures, depression, poor muscle tone and weight gain. There is also an increased risk for heart disease. The use of Synthroid (a synthetic thyroid hormone) may be your best option, but make sure you discuss all your concerns with your physician.
Ed Blonz is the author of the "Your Personal Nutritionist" book series (Signet, 1996). Send questions to: "On Nutrition," Ed Blonz, c/o Newspaper Enterprise Assn., 200 Madison Ave., New York, NY 10016 or e-mail to email@example.com. Personal replies cannot be provided.