Age changes in the livers of Costa Ricans.

Age changes in the livers of Costa Ricans have been compared with those of native and Hawaii Japanese and U.S. caucasians. In the case of the U.S. caucasians and Costa Ricans, the decrease in the number of hepatic cells is similar up to 70 years of age, but after 80 years of age the decrease is more marked in the Costa Ricans. The difference in the process of senile change among these four groups suggests that the environmental, especially nutritional, conditions during their childhood and adolescence play an important role.