Effect of snack eating on sensitive salivary stress markers cortisol and chromogranin A

Objectives  To investigate the effect of snack eating on salivary cortisol and chromogranin A (CgA). Methods  From 14∶00 to 18∶00, starting two hours after consumption of a midday meal, saliva samples were collected every 30 minutes from 15 healthy males, 7 of whom (snack group) ate a snack immediately after the sampling at 15∶00. Salivary cortisol and CgA levels were determined by ELISA. Samples were controlled according to salivary flow rates. Results  For the snack group, after snack consumption, salivary cortisol increased to exceed significance (p<0.05) at 15∶30 and rose even higher at 16∶00. In the control group, there was no such change. There was no significant change in salivary CgA in either the snack group or the control groups during the sampling period. Conclusions  These findings suggest that no food should be consumed for at least 90 mins before saliva sampling for cortisol determination and that salivary CgA is probably not affected by snack eating.