FGF21 and Cognitive impairment: Jiang et al. (2020) found that rFGF21 protects against acute BBB leakage. Another study found that FGF21 protects against HFD-induced cognitive impairment, and that FGF21 may regulate the pathogenesis of diseases caused by MHFD (Cordner et al., 2019). FGF21 is neuroprotective in aging rat brains by reducing the formation of advanced glycation end products, improving behavioral performance, and alleviating d-galactose-induced oxidative stress (Yu et al., 2015).