Refined-cereal intake and risk of selected cancers in italy.

BACKGROUND: Although consumption of whole-grain foods seems to reduce the risk of several types of neoplasms, the potential influence of a diet rich in starches and refined grains is less clear. OBJECTIVE: We studied the relation between the frequency of consumption of refined cereals (bread, pasta, or rice) and the risk of selected neoplasms. DESIGN: This was an integrated series of case-control studies conducted in northern Italy between 1983 and 1993. The subjects were patients admitted to the major teaching and general hospitals in Milan and Pordenone with incident, histologically confirmed cancers: 343 with cancer of the oral cavity and pharynx, 94 with cancer of the esophagus, 146 with cancer of the larynx, 745 with cancer of the stomach, 955 with cancer of the colon, 625 with cancer of the rectum, and 428 with cancer of the thyroid. The control subjects were 3526 patients admitted to the same network of hospitals for acute nonneoplastic conditions unrelated to long-term modification of diet. Odds ratios (ORs) for consecutive tertiles of refined-cereal consumption were computed after allowance for sociodemographic variables, education, smoking status, alcohol consumption, body mass index, and consumption of fruit, vegetables, and whole-grain foods. RESULTS: The ORs for the highest tertile of refined-cereal intake were 1.6 for cancer of the oral cavity, pharynx, esophagus, or larynx; 1.5 for stomach cancer; 1.5 for colon cancer; 1.3 for cancer of the rectum; and 2.0 for thyroid cancer. The trends in risk were significant for all neoplasms considered. CONCLUSION: Consumption of refined cereals was associated with an increased risk of cancers of the large bowel, the stomach, and other selected digestive and nondigestive sites.

Loss and/or formation of antioxidants during food processing and storage.

It is well known that natural antioxidants contained in foods are significantly lost during processing. Nevertheless it was recently demonstrated that thermal treatments can induce the formation of compounds with new antioxidant properties. This is the case of the Maillard reaction products (MRPs) whose presence as well as their potential effects have been scarcely investigated. In the present work the loss of natural antioxidants in relation to processing and the formation of MRPs with antioxidant activity were studied in different food systems such as tomato derivatives and coffee. Results showed that, although the concentration of natural antioxidants was significantly reduced as a consequence of the thermal treatments, the overall antioxidant properties of the food products were maintained or even enhanced by the development of MRPs.

Validation of a food-frequency questionnaire to assess dietary intakes in cancer studies in Italy. Results for specific nutrients.

The validity of a 77-item food-frequency questionnaire (FFQ) developed for a multicenter case-control study on diet and cancer in Italy was assessed. Trained interviewers administered the same FFQ to 452 volunteers from three Italian provinces (Pordenone, Genoa, and Forli) completed in two different seasons, at an interval of 3 to 10 months. For 395 (130 males, 265 females; median age = 52 years; range = 35 to 69 years) volunteers, two 7-day dietary (7-DD) records were available. Average intake obtained by means of the FFQ was overestimated by approximately 18% in comparison with the corresponding values based on the two 7-DD records (reference method). Pearson partial correlation coefficients, adjusted for total energy intake between the nutrient intakes assessed by the FFQ and reference method, ranged from 0.19 for vegetable fat to 0.64 for sugar (median value r = 0.46). The unadjusted deattenuated coefficients, which took into account the interindividual variability of consumption, estimated by means of the two 7-DD records, ranged from 0.29 for vegetable fat to 0.72 for starch (median value r = 0.54). The proportion of subjects correctly classified within the lowest two quintiles ranged between 59% for vegetable fat and vitamin E, and 96% for alcohol, and those correctly classified within the highest two quintiles ranged between 44% for vegetable fat and 94% for alcohol. The average proportion of subjects correctly classified within one quintile was 73%. These data indicate that this FFQ provides valid estimates of intakes for major nutrients, comparable to those reported from other studies in North America and other European countries.

Influence of some covariates on the reproducibility of an Italian semi-quantitative food frequency questionnaire.

We studied the influence of age, sex, education and time between interviews on the reproducibility of a semi-quantitative food frequency questionnaire (FFQ) developed in Italy for a case-control study on cancers of the breast and digestive tract. The questionnaire had been administered twice to 452 Italian men and women and included the weekly consumption of 77 food items or groups of foods, seven summary questions and three questions on some general dietary habits. Spearman correlation coefficients for the 77 dietary items plus the seven summary questions did not differ between males (median 0.61) and females (median 0.58), volunteers younger than 50 years (median 0.58) and aged 50 or more (median 0.59), volunteers with fewer than 10 years of education (median 0.58) and with 10 or more (median 0.59). A slightly higher Spearman correlation coefficient was found when the two interviews were conducted 5-6 months apart (median 0.60) or more than 6 (median 0.59) than when less than 5 (median 0.55). Similarly, Pearson correlation coefficients for the intake of 27 nutrients or micronutrients, plus caloric intake, computed from the FFQ showed no differences between males (median 0.65) and females (median 0.64), two age groups (median 0.67 for subjects aged < 50 years and 0.65 for those aged > or = 50), and two educational levels (median 0.68 for < 10 years and 0.65 for > or = 10 years). The median Pearson correlation coefficient for nutrients was slightly higher for those subjects who were interviewed with the planned interval (5-6 months, median 0.71) than when the interval was shorter (median 0.57) or longer (median 0.64).(ABSTRACT TRUNCATED AT 250 WORDS)