Caffeine and unsaturated fat diet significantly promotes DMBA-induced breast cancer in rats.

The following study was carried out to determine the possibility of caffeine being a promoter of breast cancer development in animals consuming vegetable fat. A controlled study, comparing the time of mammary tumor development and the number of tumors was carried out in Sprague-Dawley rats which had been given 20 mg of DMBA at seven weeks of age. This study evaluated the tumor promotional effects of caffeine alone, caffeine and unsaturated fat in combination, unsaturated fat alone, and a standard rat chow diet. The results show that the rats which consumed caffeine and unsaturated fat had the earliest development of tumor and the most multiple tumor occurrence. Average time to tumor development was 95 days. The fat or standard chow rats had an average time to tumor development of 134 and 140 days, respectively. The caffeine-alone rats had a mean time to tumor development of 188 days. The combination of an unsaturated fat diet and caffeine significantly shortened the time to tumor development when compared with the other three groups.