DEAR DR. BLONZ: I have been advised to bring down my cholesterol, or else I'm going to need to take medication. My wife insists that I cut the cholesterol that I eat, and she makes direct mention of my love of eggs. I am thinking of using cholesterol-free egg substitutes, but find them a bit pricey. As an alternative, I have been buying eggs by the dozen, separating the yolks and saving only the whites. Is this a reasonable way to avoid cholesterol? -- R.R. Palo Alto, Calif.

DEAR R.R.: It is definitely an option. The white of an egg is a source of high-quality protein; it is the standard to which all other proteins are compared. There are approximately 3.5 grams of protein in the white of a large egg. There are small amounts of other nutrients, including selenium, potassium and sodium. The yolk contains lesser amounts of protein, together with small amounts of vitamin A, folate, phosphorous, potassium and selenium.

The eggshell is a great container. As you can tell by the date stamped on an egg carton, whole eggs can usually last in a refrigerator for several weeks before they need to be eaten. Once you open the shell, however, the clock runs at a more rapid pace. Egg whites, out of the shell, have a recommended shelf life of only four days. This is something to consider when opening up a dozen at a time. You might consider freezing the whites in an ice-cube tray. Egg whites can last up to a year when frozen.

You state your desire to watch your cholesterol intake. The yolk of one large egg contains approximately 213 milligrams of cholesterol. For those with an otherwise balanced diet, the periodic use of whole eggs has been shown to have only a minimal impact on one's blood cholesterol level. If you truly have a passion for eggs, having one a day can fit within the American Heart Association's guidelines. A compromise might be to use one yolk for every two egg whites.

It might also be helpful to discuss the connection between dietary cholesterol and the level of cholesterol in the blood. Please bear in mind that this might not apply to your specific case, but in general, the American public has been persuaded to wear blinders that let them see only the fat and cholesterol in their diets as the factors responsible for elevated blood cholesterol and heart disease. This has led to thinking that reducing dietary fat and dietary cholesterol are the best ways to lower blood cholesterol and the risk of heart disease. Things, however, are not that straightforward.

First, consider that lowering dietary fat might lead to eating more carbohydrates, and if that meant a higher intake of sugars, you wouldn't be doing yourself any favors. There's little question that the levels and types of dietary fat and cholesterol can play a role, but they are not the unqualified culprits we've been led to believe. More important is a diet that's balanced and rich in fruits, vegetables, greens, whole grains, nuts, seeds, dietary fiber, etc. These supply the food factors to enhance our health. A body that is healthfully nourished is equipped to handle the fats and cholesterol in the foods it eats.

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: Is guarana better than caffeine, and is it habit-forming? My religious beliefs recommend that I keep away from caffeine. I am 67 years old and retired. Even after a good night's sleep, I suffer from tiredness as soon as I wake, as well as lower leg aches. -- M.J., Provo, Utah

DEAR M.J.: Guarana, in essence, is caffeine. The active ingredient might go under the name "guaranine," but that is just another name for caffeine. Guarana comes from a paste made from the crushed seeds of a woody shrub native to the Amazon region. Caffeine (guaranine), which belongs to the alkaloid family, is the principal active ingredient in guarana. There is a higher concentration of caffeine in guarana than in the coffee bean, the kola nut or cacao (cocoa). Guarana also contain trace amounts of other alkaloid compounds, most notably theophylline and theobromine.

Caffeine, regardless of source, can produce tolerance, psychological dependence and habituation when consumed on a regular basis. Withdrawal symptoms, including headache, drowsiness and fatigue, can occur when intake is stopped abruptly. Interestingly enough, abstinence from caffeine is a very common cause of headaches after one has gone through surgery, as presurgical routines usually require that one stop caffeine. One study published in the Mayo Clinic Proceedings found it beneficial to give a small amount of caffeine intravenously to patients undergoing outpatient surgery who were at risk for caffeine-withdrawal headaches.

Leg aches can be brought about by any of a number of situations. It may be that you would benefit from stretching and flexibility exercises, or there may be some specific medications or even herbs to try. It could even be the bed you sleep on. You need to find out whether there is anything medical going on before you begin looking for methods -- or substances -- to provide relief.

DEAR DR. BLONZ: Please explain the origin of carnauba wax. I find it on candied almonds and other foods. Does it represent a concern as a food additive? -- N.N., Pinole, Calif.

DEAR N.N.: Carnauba wax comes from the leaves of the South American wax palm. It is used as a wax or a glaze and it has "GRAS" status (generally regarded as safe). It is one of a number of such compounds used in foods. Aside from carnauba, there are the oil-based compounds petrolatum and paraffin. Shellac, another commonly used wax, comes from an Asian insect and is also used on candies, jewelry and floor waxes. Carnauba is also used in car wax.

Waxes are applied to hard-coated confections, such as candied chocolates and almonds, but they are also used with produce, including tomatoes, apples, bell peppers, avocados, cucumbers, sweet potatoes, all citrus fruits, peaches, pumpkins, eggplants, squash and nuts in hard shells. In produce, waxes are applied to retain moisture, limit flavor loss and enhance appearance. Waxes are not considered harmful and are only used in small amounts. For example, The Center for Produce Quality estimates that one pound of wax will cover 160,000 pieces of fruit or vegetables.

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: These days, many of us who are getting up there in age are taking several prescription drugs, as well as dietary supplements. What's the total effect of all these substances? I have not been able to locate a resource where one can input all that he is taking to see how it may interact. Neither of my medical doctors have a clue, but they would also like to know about such a tool. Pharmacies can process this type of information, but only as it relates to prescription drugs. Throw in glucosamine, calcium, MSM, chondroitin and others, and it seems like no one knows! What are your thoughts? -- V.S., via email

DEAR V.S.: When prescription and over-the-counter (OTC) medications come to the marketplace, they have to go through FDA-mandated screening for potential interactions. Such is not the case with dietary supplements. In today's regulatory environment, what we have is a host of ongoing laboratory experiments where we are the guinea pigs. To be sure, not every combination is going to cause problems, but the risk is certainly there.

Consider that medications and dietary supplements -- even "natural" ones -- need to be metabolized and eliminated from the body. When multiple items are in the queue for processing, it can affect the way the body does its job, which can result in abnormal blood levels of medications that need to be tightly controlled. This, in turn, can lead to unexpected -- and possibly dangerous -- effects. Matters become even more complicated when multiple prescription medications, pre-existing health conditions, alcohol and who knows what else are also on the scene.

I am not saying that all supplements should be avoided, but the time has come when responsibility falls upon us, the consumers. My advice is to learn as much as you can. The Interactions Checker on drugs.com includes prescription medications and many dietary supplement ingredients. You can add your profile of products, and it will tell you where the red flags are. This is a good place to check before adding anything else to your regimen. Don't forget pharmacists, as they have the latest resources to help answer questions. Whenever you start a new medication, take the time to consult with your pharmacist to see if there are any issues with what you are already taking.

DEAR DR. BLONZ: My husband and I just turned 80 and we try to watch what we eat. After dinner, while we read or watch TV, we enjoy a small dish of ice cream. Is there anything wrong with this? -- H.L., Pleasanton, Calif.

DEAR H.L.: It is tough to provide specific dietary advice not knowing anything about the rest of your diet or health histories. With this as a qualifier, and making the assumption that you are in good health with a good lifestyle, there is absolutely nothing wrong with having ice cream; the key is the sum total of what we have for the entire day. With few exceptions, it doesn't pay to get worked up about individual foods. You are in the eighth decade of life, so you must have been doing something right. I encourage you to enjoy each other and enjoy your lives.

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.