DEAR DR. BLONZ: I happened to be talking to a co-worker this morning -- we are both cyclists and runners. He is over 50 and I turn 50 tomorrow. Someone gave him a banana and some oranges, and he re-gifted the banana to me, saying that is one food he has cut out of his diet since he turned the half-century mark. I had never heard that people over 50 should not eat bananas. Can you provide a list of foods that I should now consider eating more of, at my age? How about foods I should eat less? Also, does potassium intake become less important to the 50+ body, and if not, what other sources should I consider if I eat fewer bananas? -- R.M., Walnut Creek, Calif.

DEAR R.M.: It's great that you are active. Don't stop! I am not sure what is behind the rejected banana. Personally, I like to use a ripe banana in my morning granola. Is your co-worker on meds where potassium intake has to be carefully controlled? Potassium is an important mineral that can be thought of as hanging around inside cells. It tends to be plentiful in whole foods. Contrast this with sodium, which can be thought of as being outside cells in bodily fluids like blood. Sodium tends to be plentiful in processed foods, and, of course, in the salt shaker. Sodium can be more of a problem, especially if there are blood-pressure issues. Even if your co-worker has some misplaced concerns about the sweet taste of a ripe banana, it is ADDED sugar that is a health concern, not the naturally present sugars in whole foods.

You ask for a list of healthful foods, but there is no magic list for those over 50 that would not have worked earlier in life. I have always favored a Mediterranean-type diet, but eat from all cuisines. There has been some great research coming out reaffirming the healthfulness of this approach. For more on the Mediterranean diet, go to http://tinyurl.com/6ayebq. If there is one great tip to carry with you, it is to follow a meal that's a bit rich with one on the lean side. Have plenty of fruits, vegetables and grains. I also love dark chocolate for dessert, but that's me. You'll get a sense of balance, and with that as your "list," you can do (and eat) just about anything.

Keep track of your general food intake as best you can, because the basic metabolic rate begins to slow as we enter our middle years. It also makes sense to adjust your exercise/workout goals as the years pass, to avoid injuries as the body shifts to middle-age and beyond. A common sense indicator is to watch the numbers on the scale, and how your clothes fit. Some change is inevitable, so it's nothing to get frantic about. It is great that you are active as it helps with weight, metabolism, staving off cognitive decline, and even with stress control; healthful foods are your best insurance.

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 am highly concerned about part of your answer regarding lactose intolerance vs. allergy: "Lactose intolerance is not the same as a milk allergy, the allergy being where there is specific reaction to the protein in the milk or milk product. Cheese should be avoided by those with milk allergies. Butter does not contain protein, but in the unusual case of an acute allergic sensitivity, even this may have to be avoided."

I think you do a disservice to the food-allergic population by this statement. Any parent of a child diagnosed with a dairy allergy is told to avoid all dairy products -- butter included. We battle long and hard to educate family, friends and schools about food allergies and the risks our allergic kids face every day.

We know that it is the protein in foods that causes the allergic reaction in people. All foods contain some amount of protein; otherwise, people wouldn't be allergic to things like vanilla, garlic, watermelon and kiwi, to name a few -- things we do not think of as having protein. So while butter may not have a high protein content, it certainly contains trace amounts and is on the no-no list for anyone diagnosed with a dairy allergy.

I understand that you write your article for the general public, but we face enough skepticism as it is when we attempt to educate people about food allergies. Statements such as the one in your column only make things harder in that regard. -- C.O., via email

DEAR C.O.: You are right. I was mistaken and I apologize to you and others who may have gotten incorrect information. The Nutrition Facts label of butter does indeed show a "0" for protein, but there is a small amount present: about 0.12 grams of protein in a one-tablespoon serving. The Nutrition Facts label rounds to the closest whole number, so anything less than one half of one gram will show "0". Although it seems minor, this amount might be enough to cause a reaction in those with an allergy. My column was written to answer a question about lactose intolerance, but when I added a brief mention about milk allergies, I should have had butter on the "NO" list. This could have been followed with a qualification that some with a milder allergy may be able to tolerate small amounts, but it was incorrect to have it the way it appeared. Thanks for your note.

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: My husband has high blood pressure and is watching his salt intake. He thinks he is being careful by not adding salt to his foods, but to me, that is only the most obvious part; it is all the hidden sodium I am concerned about. Processed foods and condensed soups have a lot of sodium, but since it is not in a form that means anything to us, it doesn't really hit home how much it is. If I could picture the sodium in a frozen dinner entree, for instance, in spoonfuls rather than milligrams, that might help. How many milligrams of sodium are there in a teaspoon of salt? -- K.M., Sedona, Ariz.

DEAR K.M.: With the exception of sugar, we add more salt to our food than any other condiment. There are 2,325 milligrams of sodium in one teaspoon (6 grams) of salt. The Daily Value -- that single set of values developed for use on food labels -- recommends an upper limit for sodium of 2,400 milligrams per day. Our health can be maintained with as little as one-tenth of that teaspoon of salt per day. As a country, we are consuming much more sodium than is necessary: The average sodium intake in the United States is between 4,000 and 5,000 milligrams per day.

About 10 percent of the salt we eat is naturally present in food, and 15 percent is added during cooking and at the table. The remainder, 75 percent of the salt in our diet, comes from processed foods.

Salt is added to processed foods for a number of reasons. Depending on the level used, it can slow the growth of certain microorganisms. Before refrigeration, salting was the only practical way to keep meat and fish from spoiling. Salt can also play a role in food texture: Processed meats such as bologna, hot dogs and lunch meats contain higher levels of salt because it helps maintain the consistency of the product. Then, of course, there is salt's role as a flavor enhancer.

The concern about excess salt is its association with hypertension, or high blood pressure, which currently affects about 50 million Americans. Hypertension is defined as blood pressure readings above 140/90. The first number (140, in this case) is the measure of the pressure in the arteries when the heart contracts and the second number (90) is the pressure in the arteries as the heart relaxes between beats.

Hypertension is called "the silent killer" because there are no warning signs until problems such as heart disease, stroke or kidney disease have already developed. There is more information at tinyurl.com/d7o7mmb. The only reliable way to find out whether you have hypertension is to have regular blood pressure checks.

Impressive data coming out of DASH (Dietary Approaches to Stop Hypertension) studies show how blood pressure can be lowered by decreasing sodium intake along with a low total- and saturated-fat diet rich in fruits, vegetables and low-fat dairy.

The bottom line? Read your labels, avoid foods overloaded with sodium and try to focus on the natural flavor of food -- not that which comes from the salt shaker.

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.