Making food choices is a daily luxury for most Americans. White bread or whole wheat? An apple or a bag of chips? But how do the nation's eating habits impact those decisions on the urban poor or on new immigrants? Epidemiologists at UC Davis School of Medicine are researching those questions.

Diana Cassady, UC Davis School of Medicine assistant professor of public health sciences and director of the school's Center for Advanced Studies in Nutrition and Social Marketing, is finding that the cheapest and most accessible foods in poor, urban areas in Los Angeles and Sacramento tend to be high in fat and low in fiber and could be a contributor to the high rate of prostate cancer among African-American men.

Using a community advocacy approach, Cassady is working to increase availability of cancer-preventing foods in poor neighborhoods. One project involves promoting supermarket-funded shuttle services so urban residents without transportation can more easily take advantage of the lower prices available in large stores. She also has worked with restaurant owners to promote more healthful menu options.

"It's not an easy task to get people to eat healthier," says Cassady. "But it's vitally important to improve the availability of healthful foods in whatever way we can. In poor neighborhoods, we see dramatic differences in rates of many diseases — diabetes, heart disease, stroke, and many cancers — that can be partly attributed to dietary behaviors."

Immigrant populations provide a unique opportunity to study the health impacts of sometimes drastically different diets after starting a new life. Marc Schenker, UC Davis School of Medicine professor and chair of the Department of Public Health Sciences, focuses his research on a range of health issues of Hispanic immigrants to California, including diet.

Principal investigator of the SHARE study (Study of Hispanic Acculturation, Reproduction, and the Environment), Schenker says he found through his research that when women first moved to California's San Joaquin Valley from Mexico or other Latin American countries, they tended to give birth to very healthy babies. However, the longer they stayed in the United States, the more likely their babies were to be born premature or underweight.

Schenker compared women in Madera, Calif., to women in the Mexican town where many of the immigrants came from, and perhaps uncovered a partial explanation: in general, dietary habits grow worse the longer the immigrants live in the U.S.

"Immigrants tend to put together the worst of an American diet with the worst of Mexican food," he says. In addition to deep-fat fried dishes, much of the native, rural diet in Mexico consists of freshly prepared fruits and vegetables. The healthy produce tends to be replaced by processed food here. Schenker found that fast-food consumption increases a whopping five-fold in the Mexican immigrant population within only one generation of arriving in the U.S., a dramatic increase that may have serious health consequences. To new immigrants, eating in fast-food restaurants "may have a bit of a cultural cachet to it," says Schenker.