For example, an RCT to evaluate the efficacy of two dosages of CRC (2 and 4 g/day) in patients with mild-to-moderate AD showed no significant differences in cognitive function, in plasma or CSF Aβ40/Aβ42 or tau, between placebo and intervention groups, perhaps due to low bioavailability of CRC [75]. This evidence concerns the gene MAPT and Alzheimer disease.