In a mouse model of Alzheimer’s disease, the ketone ester lessened amyloid β-peptide and hyperphosphorylated τ deposition, which lessened anxiety and improved cognition (62), whereas similar improvements in cognition were observed in a patient with Alzheimer’s disease who was treated with (R)-3-hydroxybutyl (R)-3-hydroxybutyrate over 20 mo (63). Here, TBXT is linked to Alzheimer disease.