DEAR DR. BLONZ: I am concerned about the dark circles under my eyes. They seem to run in my family, and I wonder if there are any vitamins, minerals or herbs I can take that might help. -- D.C., Tucson, Arizona

DEAR D.C.: Darkness under the eyes can be brought about by certain medical conditions, including allergies, dehydration, sleep difficulties and stress, and you should consult your physician if you have questions as to whether any of these might be involved.

Another common cause is the natural thinness of the skin under the eyes. The skin itself isn’t dark, but it is often thin enough to see the vascular bed underneath. This trait can indeed run in families, and its presence does not necessarily reflect any health problems. If one is fatigued, ill or under stress, the skin can become pale, and this would accentuate the darkness.

I am sorry to report that aside from using a normal, healthful diet and lifestyle to cope with life’s stresses, I am unaware of evidence showing that particular vitamins, minerals or herbs can help eliminate this problem.

DEAR DR. BLONZ: During my childhood, my grandmother from northern Italy made delicious candy from the seeds of peaches. Every fall, after we feasted on the fresh fruit, she took the seeds and fried them in butter, then added sugar till it all melted. It became the most delicious brittle candy. Now I have learned that there is poison in peach pits. Was the candy dangerous? We never got sick from it. -- L.D., Hillside, New Jersey

DEAR L.D.: It is fortunate that you did not get sick from that candy. Peach pits are not really the safest items to have in one’s diet. They, along with apricot kernels and apple seeds, are sources of a cyanide-containing compound known as amygdalin. Although a natural substance, cyanide is a very potent poison because it can effectively shut down metabolism. The body has a recovery mechanism, and as with most toxic materials, it’s the dose that determines the impact. The fact that you’re around to relate this story shows that the amount of cyanide in the peach pit brittle was insufficient to cause any obvious harm. But this is not a recipe I would pass down to future generations.

DEAR DR. BLONZ: I like to grind flax seeds and use them in my foods. I do not want them to go rancid, and was wondering if they need to be stored in the refrigerator or freezer. Also: Can fish oil capsules and other omega-3 supplements go rancid in the same way? -- E.A., San Diego

DEAR E.A.: You are correct in your approach to flax. The seed wall is designed to protect the oils within, but once the seeds have been ground, there needs to be some protection from oxidation. I would not recommend purchasing ground flax from a bulk bin, for example, where the grounds may have been sitting around for long periods of time.

If ground flax is in a well-sealed container, it should be OK at room temperature, but would do even better in the refrigerator. As regards fish oil, capsules are designed to protect their contents. If unbroken, they should be performing that function.

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: 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.