DEAR DR. BLONZ: Does putting milk in my tea (green, black or oolong) affect its antioxidant properties? I have seen and heard mixed answers on this topic. Please clarify it for me, as I do love milk in my tea. It would be very hard for me to stop this habit after so many years! -- T.L., Seattle
DEAR T.L.: First things first: Tea is a very healthy beverage choice. Population studies have suggested that compounds in tea can help reduce the risk of heart disease and other chronic ailments. Having at least one cup of tea per day, for example, has been associated with half the risk of developing a heart attack. This is thought to be due to the ability of certain compounds in tea to protect the fats in the blood (lipoproteins) from oxidation -- hence the term "antioxidants."
In relation to your question, the news is not all good, because a few studies have noted that the addition of milk seems to blunt the tea's antioxidant prowess. The final answers aren't all in, but the "milk effect" theory does seem to have some merit.
Take heart, and understand that tea is not the only antioxidant-rich substance available in our diets. As long as you have a healthful, plant-based diet overall, I encourage you to continue to enjoy your tea the way you like it. After all, eating and drinking should not always be viewed as a clinical prescription; enjoyment must have its place on the plate.
DEAR DR. BLONZ: Can soy products, such as soy milk, interfere with thyroid medication? -- R.S., Portland, Maine
DEAR R.S.: Yes, there is a valid concern here. The hormones produced by the thyroid gland regulate the metabolism in most cells of the body. Those who produce insufficient thyroid hormone are given medications that either stimulate greater production by the thyroid gland, or serve as a replacement for the hormone itself.
There is evidence that soy products can interact with the thyroid gland or its hormones, but not all soy products have the same effect. It doesn't appear that this would be a significant factor in adults eating soy as a part of a mixed diet. With thyroid medication, however, the story has an added level of complexity, because there can be a physical interaction that affects the absorption of the medication when soy is present at the same time.
It is always important to read the instructions and warnings for any medication you take. I say this because soy is not the only food with a potential interaction with thyroid medications. Many thyroid medications have specific instructions to be taken on an empty stomach to avoid potential interactions with foods. Be sure to consult your family physician, or a pharmacist, if you have any further questions.
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.