Fats in seasoning and breast cancer risk: an Italian case-control study.

The relationship between consumption of fat in seasoning and risk of breast cancer was considered in a case-control study conducted in northern Italy of 2663 cases of breast cancer and 2344 controls admitted in the same network of hospitals with acute, non-neoplastic and non-gynaecological conditions. Subjective scores corresponding to three levels (low, intermediate and high) of intake of butter, margarine and oil, together with a combined variable of these three items ("total fat"), were used to evaluate the personal use of fat in seasoning. Compared to low use, a slight but significant increase in risk was observed for intermediate and high intake of butter, oil and total fat with relative risks of 1.5 (95% confidence interval [CI], 1.1-1.9) for high intake of butter, 1.3 (95% CI, 1.0-1.6) for high intake of oil and 1.4 (95% CI, 1.2-1.7) for high intake of total seasoning fat. These results were not materially modified after allowance for a number of identified potentially distorting factors. The results of this study suggest that there is a positive association, although moderate, between breast cancer risk and intake of fat added in seasoning, which may represent an indirect indicator of the subject's attitude towards fat.