Dietary fat alters progression of some age-related changes of the immune system.

SJL mice develop resistance against tolerance between the 9th and 25th wk of life. This resistance is linked with a loss of suppressor capacity in the thymus. We have shown here that contact photosensitivity (CPS) decreases as a function of age and that this is due to an age-dependent increase in suppressor capacity. Diet fats have a differential effect on age-dependent changes in suppressor activity; a low P/S diet prevents or delays loss of suppressor activity for antibody formation and a high P/S diet prevents or delays the development of suppressor activity in CPS reactions.