DEAR DR. BLONZ: Cereals and fruit have been a part of my breakfast for decades, but about two days after switching to a new brand of cereal, I started to feel that I had become violent, moody and so depressed. I could hardly pick myself up off the floor. Of course, I stopped eating the cereal, and the symptoms did fade. The cereal is the only new food I can recall. Could this have caused this reaction? Any help would be greatly appreciated. -- S.C., Sacramento, California

DEAR S.C.: The first thing to do was to stop consuming any suspect item(s), but also to make a note of any novel experiences or exposures, including eating out, that occurred during this time. It is good that your problem went away, but the cereal, while reasonable to suspect, may not be the answer. It could have been any of a number of things, from something you ate -- including food poisoning -- to an insect bite, to a reaction to a medication you are taking. Given the nature of the reaction, it is in your best interest to do more checking. You don’t want to take on a food fear if it’s not responsible. Consider contacting your family physician or a specialist competent in the areas of allergy and immunology. Seeking assistance makes sense as it is never a good idea to experiment on oneself, especially when missteps might evoke the type of reaction you describe. If your health professionals believe that a food is a likely suspect, they can help you strategize whether and how to test suspect item(s) or to look elsewhere for clues. Uncovering suspect food reactions is a bit of a detective game, and a knowledgeable approach is key. I have heard from many individuals who have written foods or food components off their menu based on faulty logic. You can read more about food allergies and untoward reactions to food components at the website for the American Academy of Allergy, Asthma, and Immunology: b.link/food32. Also, check out the Food Allergy Network: www.foodallergy.org.

DEAR DR. BLONZ: Is it true that black pepper is very bad for you and that it is not eliminated by the body and collects in the kidneys? -- L.A., via email

DEAR L.A.: It is important to appreciate that nature represents a difficult environment, and successful plants will have evolved to produce a custom collection of phytochemicals to assure their growth and continued reproduction. Along these lines, there are compounds in black pepper (Piper nigrum) that might pose a problem, but only if an excessive amount of crushed peppercorns was a big part of your diet. Assuming there are no contaminants in the pepper, and that there is no individual sensitivity to its components, there is no evidence that black pepper is bad for you when used as a seasoning. The idea that something in black pepper collects in the kidneys does not jibe with any information that I have ever seen.

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: Our soccer-playing son has grown about four inches during this past year (he is now 12 years old), which has been fantastic. My concern relates to periods of muscular pain and pain on the soles of his feet while he plays. It is annoying, slowing him down a bit, but never to the point that he needs to stop. The coach is aware of the situation and encourages him to stretch and warm up before any practice or game. His diet is a concern as he does not make great food choices. What might you suggest? -- F.T., Hayward, California

DEAR F.T.: Rapidly growing adolescents can experience minor aches and pains as their bodies transition from "child" to "adult." It is good that his coach is aware of the issue, but you should also discuss your concerns with your family physician. It may be that the discomfort is nothing more than muscles and tendons that have become too snug for the more rapidly growing long bones. These types of "growing pains" are most often experienced at night, as that is when most growing takes place, but they can take place during the daytime as well, especially during and after the stress of his demanding exercise.

You mention the pain in your son's feet. Each foot contains 26 separate bones (one-eighth of the number in our entire skeleton), and there are a number of tendons that pass around the ankle to control the movements of the foot. It is possible that his pain could be a byproduct of his rapid growth. Stretching before a workout plus periods of rest during the game may be of help. Keep in mind, though, that whenever there is recurrent pain during growth involving the knees and legs, it is reasonable to have it checked by a physician. For foot pain, there is also the possibility of visiting a podiatrist. And let's not forget the obvious: A child's rapidly growing body can run through clothes and shoes quickly, so make sure that your son's shoes -- especially those soccer cleats -- are always fitting correctly.

As for your nutrition concerns, any period of rapid growth involves the creation of new body tissue, and that means a need for an ample supply of healthful foods to supply the raw materials to keep the process fueled and on an even keel. Good eating habits are very important, but they are often given short shrift during adolescence. At times, we, as parents, might wonder how our children are able to grow and remain in good health given what we see them eat.

There are limits to what a parent can accomplish during their child’s adolescence. Playing a parental-power card may backfire, as these are the very years during which children may have that urge to establish their independence. What you have been doing over the years can hold great sway, so set a good example and forgo any “do what I say, not what I do” approach. Adolescents take pride in seeing their bodies change and mature. You can foster healthful habits through tactful reminders that what they eat and how they take care of their body will help determine who stares back at them in the mirror. Go to b.link/teenagers50 for more on teenager nutrition from the National Institutes of Health.

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 am 45 years old, and quit smoking a year and a half ago as I have attempted to work back to better health. Since these stoppages I have gained 20 pounds and now have some gallstones. I was wondering whether a liver flush is a good thing to do to rid the liver of the gallstones and help return it to its optimal performance. -- F.S., San Jose, California

DEAR F.S.: It is not unusual to gain weight after quitting smoking. But, all things considered, that weight gain is less harmful than smoking. The best way to keep a lid on the poundage is to pay more attention to your diet, slow down at the table and increase your activity gradually. Check with your physician if there are health issues that need to be considered.

As you know, I am not a medical doctor, nor am I a specialist in liver ailments or problems with the gallbladder, but I can report that there is no solid basis to support the “liver flush” as a helpful procedure. I want to take you through my reasoning.

The gallbladder is a small gland in your midsection, close to the liver and the digestive tract. The liver produces bile, a substance that works like a detergent to help emulsify the fats in the foods we eat and make them easier to digest. Bile gets stored in the gallbladder, and when fat is present in food, a squirt of bile leaves the gallbladder, passes down the common bile duct and mixes with the food as it leaves the stomach.

Gallstones are hard, crystalline structures that vary in size from a grain of sand to the size of a golf ball. Most gallstones are made of hardened cholesterol, but some can be made of a pigment called bilirubin. Problems occur if stones clog things up in the liver or the gallbladder, or they block the common bile duct, which is also used by the pancreas. It is estimated that 10 to 15 percent of people in the U.S. have gallstones, but some may never experience symptoms. Check out a more in-depth explanation at blonz.org/v7qss.

The dubious procedure known as the “liver flush” is promoted as a natural, painless way to rid the body of its gallstones. There may be minor variations, but the flush usually involves a specialized fast or no-fat diet for a number of days, leading up to a day when you ingest Epsom salts (magnesium sulfate), followed by a hefty intake of olive oil together with some lemon juice before going to sleep.

The next day, your stool may contain some small, round opaque objects that are touted as the gallstones that have been hanging around your liver and gallbladder and causing all sorts of problems. Amazing! Or is it? These opaque globules, it turns out, are unlikely to be gallstones, but are more likely a product of the liver-flush recipe itself. A fascinating article in the April 16, 2005 issue of the prestigious medical journal Lancet titled "Could these be gallstones?" followed a 40-year-old patient who did a liver flush and passed a bunch of “stones” the following day. Upon a microscopic examination, it was discovered that those items were made up of congealed olive oil plus the other ingredients that had been administered the day before. Irrespective of the lack of evidence that it is effective, the concept of the “liver flush” continues to be promoted. My sincere congrats on stopping smoking, but please consider taking a pass on the flush.

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.