Changes in memory quotient (MQ) before and after silk fibroin protein enzymatic hydrolysate (FPEH) intake at daily doses of 0, 280, 400 and 600 mg for 3 weeks. Each value is the mean with the standard error of the mean (SEM). Groups with a different alphabetical letter are statistically significantly different on the basis of group tests following ANOVA (F = 32.97; dftotal = 62; p < 0.00013). Between group p values were the following: placebo: 280 mg, p < 0.00015; placebo: 400 mg, p < 0.0001; placebo: 600 mg, p < 0.0001; 280 mg: 400 mg, p < 0.0001; 280 mg: 600 mg, p < 0.0001; 480 mg: 600 mg, p < 0.0378.