[Engineering-MD]

From the review article “Glucose cannot be replaced as an energy source but it can be supplemented, as during strenuous physical activity when blood lactate levels are elevated [14] or during prolonged starvation [15] when blood levels of ketone bodies are elevated and BBB monocarboxylic acid transporter (MCT) levels are upregulated”

And tbh, I would be more inclined to believe the peer reviewed article on glucose metabolism in the brain by an established neuroscientist tbh.