DEAR DR. BLONZ: I wanted some information on the advantages of liquid colloidal mineral supplements. My concerns are about the risk of osteoporosis, which runs in my family, and I would be happy to switch to a product that would be more effective in preventing it. These products are more expensive than the other minerals I take, but the expense would certainly be justified if the product has a higher level of absorption, as is claimed. Is there any substance to these claims? -- B.E., Hayward, California

DEAR B.F.: Colloidal mineral products are not new. There remains a lack of competent, reliable scientific evidence to support any claims that these types of dietary supplement products bring anything special to the table.

A colloid, or colloidal suspension, is a physical state in which solid particles are suspended in a medium, such as a liquid, in a way that the solids do not settle out. The source of colloidal mineral supplements is usually clay or humic shale deposits.

Mineral absorption takes place, for the most part, in the small intestine. Pills, tablets or capsules are designed to dissolve before they reach the absorptive surfaces of the small intestine. The key question is whether, all else being equal, the body will absorb more minerals in the form of a colloidal liquid than it will from a similar amount supplied as a standard pill, powder, tablet or capsule.

Think about what you would accept as proof. Would you want positive statements and testimonials from individuals who want to sell you their products? Or would you demand some form of solid science, such as the publication of unbiased research in a peer-reviewed journal? Hopefully you would opt for the latter. Unfortunately, there is no reliable published evidence to support claims of enhanced bioavailability from minerals in a colloidal form versus similar compounds in more standard supplement forms.

Minerals are all considered inorganic elements because, unlike protein, fat, carbohydrates and vitamins, they do not contain the element carbon. A unique thing about minerals is that they cannot be synthesized or changed by the body. Like vitamins, minerals are only needed in trace amounts, and they don’t provide any calories.

The minerals in our diet are distributed throughout the foods we eat. Calcium, for example, is found in dairy products, a number of green, leafy vegetables and some nuts; magnesium is present in nuts, bananas, legumes and whole grains; and zinc is present in meats, whole grains and seafood. The distribution of the various minerals among the different foods (the same theme holds true for vitamins) is the basis for the advice to focus on variety when it comes to food selection.

Finally, there are proven strategies to help combat the risk of osteoporosis. Check out the articles at tinyurl.com/yda34bj7 and tinyurl.com/yanjrxkc.

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 was told to take a calcium supplement, but the one I purchased says to consult your doctor if you are taking estrogen, which I am. Why is that? -- J.D., Anderson, South Carolina

DEAR J.D.: Product cautions are not to be taken lightly. But for some perspective, these warnings serve the dual purpose of alerting consumers to potential concerns while affording the product's manufacturer a measure of liability protection. There are always possibilities for unforeseen interactions. When there is a known risk, or at least a suspected one, these tend to get notations on the product label or insert.

As for the particulars of your question, calcium supplements are commonly used along with hormone replacement therapy. Other ingredients in that supplement may be responsible for the caution. Get clearance from your physician, which may only involve a simple phone call.

The bottom line is that these decisions are best made with the health professional most familiar with your particular situation.

DEAR DR. BLONZ: Is there any significant difference between the protein in red meat and that found in seafood, such as shrimp? I reduced my meat intake to once a week, but I'm concerned that I’m not getting enough protein. I do a cardio workout three days a week and also work out with weights. I am interested in adding some seafood to the menu, but wondered if that protein is as good as that found in meat. -- SF, Phoenix AZ,

DEAR S.F.: There are minor differences between the proteins found in red meat and seafood, and these are mainly different amounts of the various essential amino acids. Both are considered high-quality “complete” proteins, in that they both contain good amounts of all the amino acids the body needs to make its protein. To answer your question, you should consider them comparable.

Scientists score proteins by looking at the types of amino acids they contain and then comparing them with the amino acids in our body's protein. Those that compare most favorably have the highest score. Egg whites (albumin) are usually considered to be the ideal protein, followed by dairy, fish, beef and poultry. Contrast this with lower-scoring vegetable proteins, such as corn, wheat and rice, which contain some protein but lesser amounts of one or more of the essential amino acids. Be aware that the protein listing on the Nutrition Facts label does not address protein quality.

Most people have no problem getting the protein they require. In fact, in this country, we tend to eat more protein than our bodies need. We also have fewer of the plant foods that can help provide the dietary fiber and valuable phytochemicals that support our health.

The key is to have a mix of high-quality protein foods and other protein-containing foods, including grains, legumes, vegetables, nuts and seeds.

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: As temperatures begin to rise, I turn to cooking outside on the grill. Every year I get reminded of the potential dangers of barbecuing and wanted some input about the formation of carcinogens. -- L.G., Tulsa, Oklahoma

DEAR L.G.: Now that warmer weather is in the forecast, the grills of America will spring into action. Cooking food this way does have its “dark” side in that along with adding good taste, it can add potential risk factors. But let’s flesh out this serving of risk by seeing how it fits with other behaviors we face every day.

A key issue is that when you use high heat for cooking protein foods such as meat, pork, chicken or fish, mutagens can form as the food is charred. A mutagen is a substance with the ability to cause mutations, or changes, in a cell’s genetic material. Mutations occur all the time, and most don’t amount to much because our immune system is designed to hustle them away before they mess things up. The danger is certain types of mutations occurring in an unfortunate sequence, in the wrong place and time with the body’s immune system in a state of vulnerability. This can result in a healthy cell turning cancerous.

A key issue with grilling is when fat drippings hit the heat source and become the potent carcinogen “benzopyrene,” which can rise in the smoke and get deposited on the food. (A carcinogen is a substance that causes a mutation shown to cause cancer.) Our immune system is still on the scene, but the greater your exposures, the greater your risk.

Now that we know what can happen when you cook on the grill, let’s discuss its relative risk. No, this is not the risk that your relatives will drop by unannounced; it’s a way to consider one hazard in relation to others. The classic article by Dr. Richard Wilson in Technology Review provides an interesting list of behaviors that increase the odds of death by one in a million. These include: traveling 10 miles by bicycle or 300 miles by car; rock climbing for 1.5 minutes; smoking 1.4 cigarettes; canoeing 6 minutes; having one chest X-ray in a good hospital; spending 20 minutes being a man aged 60; and eating 100 charcoal-broiled steaks.

Bikers, drivers, canoers, rock climbers and especially males over 60 would feel that these risks are acceptable. Given this, the relative risk of eating grilled steaks, while it should be acknowledged, might seem a bit less onerous. The point here is not to dismiss risk in a cavalier manner. If you char your foods, these substances can be formed. If you eat charbroiled foods, they can enter your body. But there are steps to lessen this risk. For example, don’t place the food directly over the heat to prevent the drippings from generating smoke. (Check more ways to reduce the risks when grilling at b.link/fs82gp.)

Finally, don’t lose sight of that big picture. If you are worrying about grilling while sitting in the sun without sunscreen, or are smoking, overweight, with untreated high blood pressure, and with an inactive lifestyle eating an unhealthful diet, your priorities are all wrong. These factors represent a greater risk than the chicken on the grill.

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.