DEAR DR. BLONZ: I recently purchased a bag of grated mozzarella cheese at a warehouse store. I had expected the ingredient list to read "milk, salt, enzymes," which is what you find on blocks of cheese. But this bag also included "natamycin to protect flavor" and "powdered cellulose to prevent caking." What is natamycin? Do I need to be concerned about either of these ingredients' effect on health? -- D.D., PhoeniX

DEAR D.D.: It can be troubling to see unknown ingredients on a food label: You're not quite sure what they're there for, and if they have imposing-sounding names, it is reasonable to be concerned that they might be unwholesome. Such ingredients, however, often sound more onerous than they actually are.

Natamycin is a naturally occurring antifungal preservative compound that can be used to help prevent the growth of undesirable molds or yeasts on cheese. It is used with certain cheeses because it doesn't work against the friendly bacteria that are essential for flavor development during the ripening process. It will most commonly be found on grated and sliced cheeses, due to their increased surface area. (This is one reason I prefer to buy blocks of cheese, then slice or grate them as needed.)

You can find products that don't contain this preservative, but it is doubtful that it is cause for any significant concern. The small amounts used act locally and, along with the protein in the cheese, will be denatured and destroyed during the digestive process.

The powdered cellulose is there to prevent the grated mozzarella from clumping together. This is a naturally occurring carbohydrate from plants. Cellulose, which is not digested, is the most plentiful carbohydrate substance in nature. It is actually considered to be dietary fiber, but the tiny amount needed for anti-caking won't even register on the food label.

Regarding food additives in general, you can limit the problem by sticking to whole, or minimally processed, foods. But even this is no guarantee. As a group, food additives are a mixed lot, containing a variety of substances that accomplish some rather amazing things. They are all chemicals -- one and all -- but the same can be said for all foods we eat, whether they come fresh from the garden or from a package on your grocer's shelf. The Food and Drug Administration has a reference on food additives at tinyurl.com/aub75ck, and there is another one at the U.S National Library of Medicine: tinyurl.com/hh84vuq.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I have a low, steady ringing in my ears. It's more noticeable at night, when everything is quiet. I have not been subject to any loud noises or any colds or sicknesses. This has been going on for four weeks. Could it be related to my being pregnant, or the fact that I am now taking a prenatal vitamin with iron (150mg)? -- D.S., Baton Rouge, Louisiana

DEAR D.S.: Ringing in the ears, also called tinnitus (tih-NY-tuss), can represent a wide spectrum of phantom sounds brought about by a variety of conditions. It is often accompanied by hearing loss. I am familiar with tinnitus, as it remains a most unwelcome visitor in my own life. Hopefully yours is temporary, so let's take a brief look at the buzz on this annoying condition.

Normally, external sound vibrations strike the eardrum, causing the bones of the inner ear to vibrate and conduct the sound to the acoustic nerve. The (mechanical) acoustic vibration gets translated into an electric nerve signal, which then travels to the brain for interpretation. With tinnitus, something inside the head causes the acoustic nerve to fire. This "something" might be an inflammation, infection, blockages, malfunctions with the inner ear, otosclerosis (an overgrowth of the inner ear bones), pressure from abnormal tissue, a blood pressure issue, anemia, an allergy, a reaction to a medication (even something as common as an OTC pain reliever), a cumulative effect of exposure to loud noise, or the actions of a toxic agent.

As you can see, it is a long list.

There is an increased prevalence of tinnitus during pregnancy, which could indicate that your symptoms are temporary. I think it would be in your best interest to mention this to your physician or obstetrician, and possibly to have it checked out by an ear specialist. An expert can help you better understand what is going on, and rule out any possible situation that could be of concern during your pregnancy. In addition, there may be some intervention that could help prevent matters from getting worse.

Check out the fact sheet and article on tinnitus from the U.S National Library of Medicine: tinyurl.com/ztvu2pu and tinyurl.com/hwrdxok.

DEAR DR. BLONZ: I wanted to report a reaction my daughter had to rose-hip tea, as I know rose hips are ingredients in many vitamin C products.

In her late teens, my daughter was covered with hives within an hour of drinking some rose-hip tea. I rushed her to the nearest doctor, who informed me that the hives, which were even in her throat, could have caused suffocation, or even death, had she been brought in even one hour later. -- M.D., Chicago

DEAR M.D.: I appreciate the importance of your note, and I trust that others will take heed to the lesson learned by you and your daughter. Your story is a reminder about the potential dangers of food allergies, and it counsels alertness and caution when trying new foods. Any untoward reaction -- especially one that can affect breathing or blood pressure -- is not to be trifled with, and medical attention should be sought immediately. Read more on allergic reactions at: tinyurl.com/ne3g6zl.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I work long hours as a programmer, and gravitate to high-calorie foods such as pizza and hamburgers. I don't have much time for lunch, and these foods are nearby, quick and reliable. I tend to do takeout for dinner. I am in my 30s and this type of eating has been working so far, but I'm wondering about my risks for chronic disease. -- T.T., Santa Clara, California

DEAR T.T.: While young, we have a resilience that allows us to feel that we can eat just about anything and not suffer ill effects. Unfortunately, continued abuses add up, and by the time we reach our later years, we have to live with the cumulative effects. The sneaky side of chronic diseases is that you often have no idea that things are headed in a bad direction until, decades later, the disease emerges to take over your life.

From that point on, it becomes about damage control. Some patients pick up the gauntlet and counter their new condition with radical changes in their diet and lifestyle, while others maintain their bad habits and rely on the medical establishment (drugs, surgery, etc) to mitigate the problems. Either way, it is a frustrating situation, which is precisely why healthful habits as a form of "health assurance" make such amazing sense. The sooner you start, the better off you will be.

Not everything you eat has to be a paragon of healthfulness. On the contrary, my attitude has always been that you can eat a wide variety of foods, as long as the overall healthful tone of your diet (and your lifestyle) remains intact. If the pizza, burgers and takeout you mention represent a big slice of what you eat every day, however, you've certainly got some gaps to fill.

Think about it this way: When doing a project at work, would you opt for substandard components? Would you use a programming language or buggy subroutines inappropriate to your needs? The programming adage "garbage in, garbage out" is akin to the dietary dogma "you are what you eat." Both reflect that what we put in -- into our bodies or our computers -- limits what we can expect back out.

I encourage you to take a close look at the totality of what you eat, as well as what you are not eating. You could help your case by starting the day with a high-fiber breakfast with fruit, then add a big salad or fresh vegetables with your lunch. Have some fruit and nuts as a snack during the day, and be sure to have a good-sized serving of greens with dinner.

Additions such as these can effectively limit the amount of fast foods you eat, as well as their impact on your immediate, and long-term, health.

Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.