The role of energy and fat in cancers of the breast and colon-rectum in a southern European population.

BACKGROUND

Several uncertainties remain with respect to the role of intake of fat and/or total energy in the etiology of cancer of the breast and colon-rectum.

PATIENTS AND METHODS

Between 1991 and 1996, 2569 women with incident breast cancer (median age: 55 years), 1953 subjects with cancer of the colon-rectum (median age = 62), and 5155 hospital controls were interviewed in six Italian areas. The validated food frequency questionnaire included questions on 78 foods and recipes and specific questions on individual fat intake pattern.

RESULTS

Significant trends of increasing breast and colorectal cancer risk with increasing intake emerged for bread and pasta, pork and processed meats and potatoes (breast cancer only), cakes and desserts (colon-rectum cancers only), and refined sugar. Most vegetables were inversely associated with cancer of the colon and rectum, whereas only carrots and raw vegetables seemed to lower breast cancer risk. High fruit intake was associated only with a reduction of rectal cancer. Total energy intake was directly associated with all cancer sites. Among macronutrients, high intake of starch and saturated fat seemed to lead to an increase of cancer risk. High intakes of polyunsaturated fatty acids (chiefly derived from olive oil and seed oils) were protective. Among micronutrients, beta-carotene, vitamin E, and calcium showed inverse associations with breast and colorectal cancer risk.

CONCLUSIONS

An excess of energy intake, particularly from refined bread and pasta, can be an unfavourable feature of the Mediterranean diet, in the presence of a sedentary lifestyle.