DEAR DR. BLONZ: Aluminum cookware has been rumored to be associated with some health problems. We have been using a set of premium hard-anodized aluminum pans, but some friends who were over for a meal were saying I should replace them. These are quality products, but I do not want to put my family at risk. I noticed that this company’s product literature has dropped the word “aluminum” and now just says that their cookware is hard-anodized. -- S.L., Tucson, Arizona

DEAR S.L.: This question about the potential dangers of aluminum cookware comes up periodically. It is based on circumstantial evidence, rather than established evidence of cause and effect. The concern carries special weight because it involves the risk of Alzheimer’s disease: the progressive, as-yet incurable loss of mental faculties. Some claim that a “toxic” level of aluminum in the brain leads to the disease.

There is no evidence that exposure to aluminum through the diet is responsible for Alzheimer’s disease. One part of the puzzle is that patients’ levels of aluminum in their blood, hair and skin remain normal, which would suggest we are not dealing with an aluminum “toxicity” as much as a malfunction in brain tissue that results in aluminum’s accumulation.

It is important to understand that aluminum is present throughout our environment. In fact, it’s the third most common element in the Earth’s crust, and occurs naturally in plant and animal foods. It is also found in some food additives, medications such as antacids, and deodorants. To put this in perspective, a study in the journal Food Additives and Contaminants (Jan./Feb. 1995) reported that if you were to take an entire day’s food supply, store it in aluminum containers, prepare it in aluminum cookware and wrap it in foil, your aluminum intake for the day would be approximately 6 milligrams. If you did that for a full week, that would be a weekly intake of 42 mg. The tolerable weekly intake, set by a joint U.N./World Health Organization expert committee, is just over 3 milligrams per pound of body weight: so, for a 150-pound individual, 450 mg per week would be tolerable. That’s quite bit higher than the 42 mg if the aluminum exercise were to be done for an entire week.

Shifting from this information to other issues, the new breed of hardened (anodized) aluminum is considered safe for all foods, including high-acid foods. This means that little or no aluminum would be released into the food, irrespective of the type of food prepared. Hardened aluminum, therefore, gets moved even further down the suspect list.

I don’t know why the company changed its advertising, but it may be a desire to distinguish their product from other forms of aluminum cookware -- even though the connection between eating foods prepared with aluminum cookware and the risk of disease remains to be established.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 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: Please comment about the concept of the cold/ice water diet. It is a means of losing weight that takes advantage of the energy used to bring the cold water up to body temperature. I have seen this described as a passive, but smart, way of burning extra calories. As I recall, a calorie is the amount of heat it takes to raise one gram of water one degree Celsius. So if a person drank 8 ounces (about 227 grams) of cold water at 5 degrees C (41 degrees F), and the natural functions of the body raised the temperature of the water to 37 degrees C (98.6 degrees F), then wouldn’t the body burn 7,264 calories (227 x 32) in the process? Can this be true? -- C.I., Chicago

DEAR C.I.: Boy, wouldn’t that make things simple: the ultimate “chill” diet. Make ice cubes a regular part of your diet and watch stored calories melt away!

It is true that our body seeks to maintain its normal operating temperature of about 98.6 degrees Fahrenheit (37 degrees C). That is the temperature at which most chemical reactions are designed to take place. It’s also true that calories are expended heating up water, or any other cold food. The slap of reality here is that the number of calories burned by bringing cold items up to body temperature is not what you had projected. Your weight-loss hopes fall victim to the thousandfold big “C”/little “c” caloric confusion.

The calorie (note the lowercase “c”) is a unit of energy in the metric system, and it is defined as the amount of heat required to raise one gram of water one degree centigrade. But the calories that are used to describe the energy in foods (or the energy expended by physical activity) are actually kilocalories (kilocals for short), which are the equivalent of 1,000 small “c” calories. One Calorie = 1 kilocalorie = 1,000 calories.

Food/activity calories should have that capital “C” to start the word, but common parlance and usage have blended the two together. In the mind of the average individual, a calorie is a Calorie is a calorie. Even the Nutrition Facts label mixes it up, using the uppercase “C” in some places, but then saying that “Percent Daily Values are based on a 2,500 calorie diet” (which would be the equivalent of 2.5 Calories). No wonder the distinctions get lost. Scientists use the term kilocalorie to avoid confusion with uppercase and lowercase “c.”

Doing revised math with your water-heating exercise, the 8 ounces of water weighs 227 grams, and heating this up 32 degrees would use up approximately 7,264 calories (again, note the small “c”). This is the equivalent of 7.264 (big “C”) Calories, and that is less than a gram of fat. Sorry to take the heat out of your diet plans.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 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 want your help in settling a cholesterol discussion involving chicken. Does removing the skin from chicken before you eat it get rid of the cholesterol? Also, I grill chicken with the skin on to keep it from drying out, giving people the option of removing it before the meal. How does this compare with removing the skin before cooking? And to reduce cholesterol in other types of meat, does it help if I purchase leaner cuts? -- C.L., Phoenix

DEAR C.L.: There is a small amount of cholesterol in the skin and fat, but most is in the meat -- both light and dark. This holds true for beef, pork and lamb, as well. Buying leaner cuts does little to reduce the cholesterol in the meal.

While the various types of blood cholesterol continue to be monitored, concern about the cholesterol in our foods has shifted a bit. Research evidence points to the level of fat in the diet -- especially partially hydrogenated fat and saturated fat -- as having more of an effect on our blood cholesterol than the amount of actual cholesterol in the foods we eat.

Also key is the need to avoid the excessive intake of simple sugars. Those naturally present in fresh fruits are fine, but we need to avoid added sugars as much as possible. The combination of an active lifestyle with a balanced diet -- focused on fruits, vegetables, grains, nuts and seeds -- is the best move.

Personally, I use my grill for many types of foods. Regarding chicken, I favor keeping the skin on during grilling for flavor and to prevent dryness. Care, of course, must be taken to avoid flare-ups when grilling skin-side down. Once the chicken is cooked, the skin can be removed, if desired. And it should definitely be removed if the skin has been blackened. So, while you need to cook foods completely, avoid overcooking and keep in mind that food does continue to cook for several minutes after it has been removed from the grill.

DEAR DR. BLONZ: I have some orange trees, and I freeze the juice since there are too many oranges to eat while fresh. Does freezing take away any of the good nutrition of the orange? -- J.F., Chula Vista, California

DEAR J.F.: Fresh oranges, or their juice, are a wholesome food. The orange contains vitamin C, folic acid, vitamin B6 and potassium, in addition to a variety of phytochemicals designed to help it thrive in the sun. There is no problem with fresh-frozen orange juice; the goodness in the fresh juice will be waiting to jump into your glass after it defrosts.

Freezing is an interesting method of food preservation. Cold slows down reactions associated with spoilage. The bonus with freezing is that water forms crystals when frozen, making it unavailable to bacteria and other microorganisms that need water to thrive.

You want to be sure to keep any food well covered, with a minimum of dead space around it. When freezing, allow for expansion. Frozen water crystals take up about 9 percent more space than the same quantity of water as a liquid.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 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.