Dear Dr. Blonz: I would like clarification about cancers and the difference between a mutagen and a carcinogen. I am inquiring about any connection between liquid smoke flavoring and the risk of cancer, and how this differs from the smokiness that develops in grilled foods.

— S.P., Raleigh, North Carolina

Dear S.P.: Cancers stem from a “mistake” in a cell’s DNA, the inherited genetic blueprint that tells cells what to do. We depend on our immune system, the body’s internal defense system, to recognize foreign substances and abnormal cells. Aberrant cells, or substances that don’t belong, are identified and eliminated before harm is done. Cancer takes root when the immune system is not functioning optimally or when the cell is reprogrammed in a way that confounds attempts at control. But even then, cancer is not a sure thing; precancerous cells can survive only if conditions favor their growth. Substances that alter genes can be categorized into two main types: mutagens and carcinogens. A mutagenic substance can cause mutations or changes in a cell’s genetic material; these may or may not lead to cancer. It is essential to recognize that our bodies are constantly exposed to mutagens. For example, every time we step out into the sun, take a deep breath of less-than-pristine air or eat, heat or cook certain foods.

Most mutagens don’t amount to much because our immune system is trained to spot and hustle them away before they have a chance to cause problems. There is an unpredictable risk as a minute percentage of mutations might take place in the wrong place at the wrong time, and this, theoretically, can progress to cancers or cause congenital issues. Carcinogens, by contrast, have a proven ability to cause cancerous changes. Our immune system is trained to spot and remove any dangerous changes. But as with the danger from mutagens, it is not a foolproof system. The greater the type and amount of exposure, the greater your risk.

Liquid smoke-type products are flavorings made from the condensed smoke of burning hardwood chips or sawdust. This type of flavoring is a convenient way to add a grilled flavor without the need of a grill. The flavor components from the burning wood are captured in water, concentrated to the desired consistency and then aged. One of the advantages of this product is that most carcinogens in smoke are fat-soluble, yet this product only provides flavor-rich, water-soluble elements. Another plus is that you avoid inhaling the smoke and its damaging particulate matter, which can harm the lungs.

Many of these products filter out dangerous substances as a part of the production process; be sure that the one you are considering takes this step. Some of the flavorings, however, can contain mutagenic substances formed when wood is burned. Exercise caution as this is not a “clean slate” product. However, if used as an infrequent part of an otherwise healthy diet and lifestyle, the risk could be considered negligible and lower than that of charred or smoked foods.

Email Ed Blonz at cctimes@blonz.com.