Dietary factors and cancer in Israel.

The risk of developing cancer is relatively higher in the European-born Israeli population than in those originating from the Middle Eastern or North African countries. The majority of cancer sites with a higher risk in the European groups involve the gastrointestinal and reproductive systems. Certain leads suggest that at least some of these differences may be attributed to diet. Data based on case-control studies are provided; they indicate a high consomption of starches among gastric cancer patients and a lower fiber consumption in patients with cancer of the colon. The latter observations may be extended to cancer of the breast, ovary, and corpus uteri, assuming an interplay between the concentration of bile degradation products and hormone metabolism. Although a low fiber consumption seems a more likely mechanism, a higher fat consumption is also compatible with this model. However, due to the complexity of human nutrition, it seems unwarranted to incriminate any single dietary factor in carcinogenesis. A better understanding of the metabolic pathways, coupled with consistent observations from distinct populations, should be looked for.