A modified Mediterranean‐ketogenic diet favorably modulates the metabolic profiles of mild cognitively impaired individuals
Richa Batra, Kevin Huynh, Annalise Schweickart, Bryan J. Neth, Matthias Arnold, Gabi Kastenmuller, Peter J Meikle, Suzanne Craft, Jan Krumsiek, Rima F. Kaddurah‐Daouk- Psychiatry and Mental health
- Cellular and Molecular Neuroscience
- Geriatrics and Gerontology
- Neurology (clinical)
- Developmental Neuroscience
- Health Policy
- Epidemiology
Abstract
Background
Impaired glucose utilization is central to the pathogenesis of Alzheimer’s disease. In a hypometabolic state, the brain depends on alternative sources of energy, including amino acids, fatty acids, and ketone bodies (KBs). As KBs can cross the blood‐brain barrier, it is considered that a ketogenic diet could augment the high energetic demand of the central nervous system (CNS). A ketogenic diet is already a part of clinical care in epilepsy a CNS disorder. However, the holistic benefits of this diet for Alzheimer’s remain to be determined.
Methods
A randomized crossover pilot trial was conducted where participants consumed either the Modified Mediterranean‐Ketogenic Diet (MMKD) or the American Heart Association Diet (AHAD) for 6 weeks, followed by a 6‐week washout, after which the respective other diet was consumed for 6 weeks. The cohort included both mild cognitively impaired (MCI) and cognitively normal (CN) individuals. Serum and cerebrospinal fluid (CSF) samples of these individuals were profiled using two metabolic platforms: MS‐based and NMR‐based metabolomics. Diet‐related changes in levels of metabolites were determined using linear‐mixed effect models with age and sex as confounders.
Results
We identified post‐diet changes in the two diet groups (AHAD and MMKD), two cognitive groups (MCI and CN), and two fluids (serum and CSF). AHAD was associated with a decrease in serum levels of only a single metabolite, glutamine. MMKD led to widespread lipidomic and metabolic changes in the serum of mild cognitively impaired individuals. Remarkably, MMKD was associated with the reversal of AD‐related metabolic alterations identified in large cohorts like ADNI, AIBL, ROS/MAP, and signature for incident dementia in large epidemiological studies. The post‐MMKD changes include correcting metabolic dysregulation in branched‐chain amino acids, triglycerides, and plasmalogens a class of lipids implicated in membrane structure and function. Peripheral‐central metabolic correlations will be shared.
Conclusion
Our findings highlight the potential of dietary interventions, specifically the MMKD, in improving the cognitive and metabolic state of individuals with MCI. Further investigation is needed to capture the entirety of MMKD‐related modulation in metabolic profiles and the resulting benefit for AD.