Dietary habits, internal migration and social class in a sample of a northern Italian population.

The study of migrants has generated interesting hypotheses on the etiology of different types of cancer. In particular, it has been suggested that both colon and breast cancer could be related to living conditions, including diet, in the country of immigration. Considerable internal migration occurred in Italy in the sixties. We studied a random sample of 1,400 subjects living in the city of Torino and the province of Varese. They were interviewed with a detailed questionnaire about their dietary habits, and the consumption of several nutrients was considered according to the area of birth and social class. The hypothesis we tested was whether, after controlling for social class, there were different dietary habits among the migrants and the native population, and whether such differences could help in the formulation of etiologic hypotheses on cancer. We found that the intake of saturated fatty acids and cholesterol was lower among the migrants from the south, whereas they consumed higher levels of vegetables than people born in the north. The different intake of saturated fatty acids and cholesterol seemed to be attributable mainly to the consumption of butter, for which the south/north ratio was as low as 0.47 in men and 0.56 in women. Important gradients by social class were also suggested for several nutrients.