The menthol myth

Dear Buzzed,

Loving My Menthol

Dear Menthol Lover,

While we can't set your mind at ease about smoking cigarettes, we can at least reassure you that the menthol in menthol cigarettes is not crystallizing in your lungs or otherwise damaging your health. There are hundreds, and perhaps thousands, of health-damaging molecules in cigarette smoke -- from carbon monoxide to nicotine to formaldehyde to polycyclic hydrocarbons -- that cause cancer. However, you probably don't need to worry too much about the menthol.

Menthol is a molecule that is purified from plants of the mint family, either peppermint (Mentha piperita) or cornmint (Mentha arvensis). It has been used in products including toothpaste, cold remedies and peppermint candies for at least 100 years.

Menthol makes skin feel colder by stimulating the nerve endings that detect cold. This same cooling feeling gives the sensation of nasal decongestion, and cools the taste of burning cigarettes. Providing this feeling and a nice aroma is about all that menthol does. Although menthol is widely used in cough and cold preparations, it doesn't do too much besides make the air smell and feel nice.

Fortunately, menthol is pretty safe. Animal studies have shown that even high doses of menthol delivered over a long time don't cause obvious organ toxicities. Even when burned, menthol doesn't produce carcinogens. Menthol in cigarettes is carried to the liver and degraded into harmless compounds.

So where did the myth about menthol cigarettes originate? It comes from an association between certain forms of cancer and use of menthol cigarettes. African-Americans experience much higher rates of smoking-related cancers, including lung cancers and mouth and throat cancers. They also are much more likely to smoke menthol cigarettes. (Seventy-five percent of black smokers smoke menthol cigarettes, compared with 25 percent of white smokers.)

Since the early '90s, scientists have tried to determine whether this relationship is causal, but results have been inconclusive. While a few studies have shown that smoking menthol cigarettes in particular is associated with an increased incidence of lung cancer, most have not. Researchers considered the possibility that smokers inhale more frequently and more deeply when smoking menthol cigarettes and, as a result, take in more carcinogens.

In fact, most studies find that if there is any difference among smokers at all, those who smoke menthol cigarettes take smaller and fewer puffs of each cigarette. So if the problem isn't menthol cigarettes, what is it? One idea is that there are racial differences in the liver's enzymes that can deactivate cancer-causing molecules in cigarette smoke. Such differences are common, and represent a definite possibility.

While you probably don't have to worry too much about the menthol in your cigarettes, you still have to be concerned about the other molecules in cigarettes; they certainly are not improving your health. Since you are health-conscious enough to worry about the menthol, maybe now is the time to think about trying a smoking cessation program or the nicotine patch.

Buzzed appears every Wednesday in Salon Health. Do you have a question? E-mail us at buzzed@salon.com.