Brain uptake and metabolism of ketone bodies in animal models.
Level 5 - mechanism / opinion, no new human data
Narrative review of animal model mechanistic studies
PubMed 14769485 · doi:10.1016/j.plefa.2003.07.006
What was done
This narrative review synthesized evidence regarding the uptake, transport, and metabolic fate of the ketone bodies beta-hydroxybutyrate and acetoacetate in developing animal brains, focusing on suckling rats as a model of physiological ketosis during lactation.
What was found
Suckling rodents exhibit higher expression and activity of monocarboxylate transporters and ketogenic enzymes than mature rats. Ketone bodies supply approximately 30% to 70% of the total energy metabolism balance in the immature rat brain and act as substrates for amino acid and lipid biosynthesis. This ketone utilization spares glucose for metabolic pathways that ketones cannot fulfill, such as the pentose phosphate pathway (yielding ribose and NADPH), and for regional glucose needs supporting the emergence of vision, audition, and integrated behaviors.
Why it matters
It outlines the metabolic division of labor between ketone bodies and glucose during early brain development, illustrating how ketones support both bioenergetics and biosynthesis while sparing glucose for specialized functional maturation.
Limits
The abstract reports on a narrative review of animal studies without systematic search criteria or primary sample sizes. Findings from suckling rodent models cannot be directly extrapolated to human infant neurodevelopment without clinical validation.
Cited by
- contradicts Certain biological pathways in the brain cannot utilize ketones and can only use glucose because ketone molecules are too small.