A 2-year feeding study of instant. Coffees in rats. II. Incidence and types of neoplasms

Abstract

Regular and decaffeinated instant coffees were incorporated at the maximum tolerated level of 6% in a standard commercial diet and fed ad lib. to male and female rats for 2 yr. The average daily intake of coffee, not considering the first 4wk, was 2·9 g/kg for males and 3·5 g/kg for females, corresponding to about 80 cups for a 70-kg man and 70 cups for a 50-kg woman. With the exception of caffeine, the other technological variables, such as freeze- and spray-drying, decaffeination and extraction rates, did not influence the incidence and types of neoplasms in a significant manner. With three of the treatments involving high levels of caffeine, the incidence of neoplasms was significantly lowered. In all treatment groups, the total number of neoplasms was either similar to or lower than the total in the control group.