Campus Connection

Waiting to exhale
(continued)

Next, with a grant from the National Institute of Environmental Health Sciences, Witschi fed the mice substances that other researchers thought pre- vented cancer. These included a phytonutrient found in citrus peels, a selenium compound, aspirin, green tea and two kinds of isothiocynates (an antioxidant nutrient) found in cabbage and watercress.

Once fortified, the mice were then exposed to heavy tobacco smoke and then clean air. Researchers would expect 89 percent of the mice to develop lung cancer, with an average of 2.4 tumors per animal. None of the other compounds made a dent in this statistic. But one regimen, a combination of dexamethasone and myoinositol, caused tumor incidence to drop to 62 percent and to one tumor per animal.

Dexamethasone and myoinositol were also effective in reducing tumors in mice who were fed the substances after they had been exposed to smoke for several months and then exposed to clean air - a model for people who quit smoking.

What this holds for the future is anyone's guess. Besides cereal, myoinositol is found in beans and rice. Dexamethasone is currently prescribed for people with asthma and rheumatoid arthritis. Theoretically, someone could get these substances from their diet and a quick trip to the doctor's office. But the dosages and duration of the regimen are questions that still need to be answered in studies that involve humans. Witschi is working with a researcher at the University of Minnesota to make that happen.