Purpose of review: Non-invasive neuroimaging methods have been developed as powerful tools for identifying in vivo brain functions for studies in humans and animals. Here we review the imaging biomarkers that are being used to determine the changes within brain metabolic and vascular functions induced by caloric restriction (CR), and their potential usefulness for future studies with dietary interventions in humans.
Recent findings: CR causes an early shift in brain metabolism of glucose to ketone bodies, and enhances ATP production, neuronal activity and cerebral blood flow (CBF). With age, CR preserves mitochondrial activity, neurotransmission, CBF, and spatial memory. CR also reduces anxiety in aging mice. Neuroimaging studies in humans show that CR restores abnormal brain activity in the amygdala of women with obesity and enhances brain connectivity in old adults.
Summary: Neuroimaging methods have excellent translational values and can be widely applied in future studies to identify dietary effects on brain functions in humans.
Keywords: Alzheimer’s disease; anxiety; brain aging; caloric restriction; cerebral blood flow; glucose metabolism; ketone bodies; magnetic resonance imaging (MRI); magnetic resonance spectroscopy (MRS); mammalian target of rapamcyin (mTOR); memory; positron emission tomography (PET); translational research.