Ischemic preconditioning with a ketogenic diet improves brain ischemic tolerance through increased extracellular adenosine levels and hypoxia-inducible factors.
Level 5 - mechanism / opinion, no new human data
Preclinical animal and in vitro laboratory study
PubMed 28427869 · doi:10.1016/j.brainres.2017.04.010
What was done
Mice were fed a ketogenic diet (KD) for three weeks and subjected to reversible middle cerebral artery occlusion (MCAO). Researchers evaluated infarct volume, regional cerebral blood flow, and extracellular adenosine levels during ischemia and reperfusion phases. In vivo and in vitro experiments were conducted to evaluate adenosine A1 receptor pathways, Akt and ERK1/2 phosphorylation, and expression of HIF-1α, HIF-2α, VEGF, and EPO.
What was found
KD preconditioning significantly decreased brain infarct volume, increased regional cerebral blood flow, and elevated extracellular adenosine levels during both ischemic and reperfusion periods. Protection was mediated via the adenosine A1 receptor, leading to increased Akt and ERK1/2 phosphorylation and upregulation of HIF-1α, HIF-2α, VEGF, and EPO. No exact numerical data or effect sizes are provided in the abstract.
Why it matters
This study outlines specific molecular mechanisms (adenosine A1 receptor activation and HIF pathways) through which dietary preconditioning can enhance brain ischemic tolerance in preclinical models.
Limits
The study is entirely preclinical (in vitro and mouse model), with unknown translational relevance to human stroke. The abstract omits sample size, numerical results, dietary composition details, and confidence intervals. It evaluates only preconditioning, not treatment after stroke onset.
Cited by
- supports Fasting and ketogenic diets increase adenosine levels in the brain, and fasting can acutely increase cerebral blood flow by 30%.