A comparative study on the role of diet in breast cancer in a high-risk ethnic group

Breast cancer incidence is three to four fold higher in the Parsi ethnic community than in the Non-Parsi population living in the same area: Parsis are westernized in their life style and some studies have reported that their dietary habits are comparable to those of Europeans. The question as to why the Parsis show such a high incidence of breast cancer remains, however, without a satisfactory answer. Besides genetic factors, claimed differences in the dietary intake of the Parsis could perhaps provide a lead to find an answer to this question. The present study addressed the role of diet, its composition, and the caloric intake in the Parsis in relation to the high incidence of breast cancer reported among them. We analyzed the composition of serum lipids and fatty acids in relation to the food consumption among Indian (Parsis and Non-Parsis) and French patients with breast cancer. The data obtained were compared with those from women with benign lesions and from normal subjects. Our findings revealed that the food habit and the quality of food intake were grossly the same among the Parsis, the Non-Parsis, and the Europeans. The caloric intake, however, was higher in Parsi women with a breast cancer history as compared with that in Non-Parsi or European patients. In general, the overall caloric intake among breast cancer patients was higher than that of those with benign breast lesions or the control individuals. On the other hand, we observed no significant difference in the levels of total cholesterol, triglycerides, and phospholipids between the European and the Indian patients or the controls. We also focused attention on the saturated and unsaturated (mono and poly) fatty acids. A proportional variation of the monounsaturated fatty acids in free fatty acids and of the polyunsaturated ones in phospholipids was seen in different categories of the individuals. Current views on promotion and initiation of cancers imply a major role for environmental factors, particularly the diet. Our results do not indicate that the dietary intake of Parsis is the major risk factor involved in the etiology of breast cancer. In any case, it alone can not account for the high incidence of breast cancer seen in this community.