The study strongly suggests that using ketones for energy more often than glucose could lead to better brain function, particularly for protecting the brain from aging effects. The study used functional MRI (fMRI) and found that brain networks were destabilised by glucose and stabilised by ketones, regardless of whether ketosis was achieved through a ketogenic diet or an exogenous ketone ester. The authors concluded that the brain network destabilisation may reflect early signs of hypometabolism and that dietary interventions resulting in ketone utilisation may help protect the aging brain.

The summary of how the study supports this idea is:

Key Findings: The study found that brain networks were destabilised by glucose and stabilised by ketones. This effect was observed whether the ketones came from a ketogenic diet or an exogenous ketone ester.
Ketones and Energy: The authors note that ketones increase the Gibbs free energy change for ATP by 27% compared to glucose, meaning ketones provide a more energetically efficient fuel for the brain.
Biomarker of Aging: The study established that brain network destabilisation is a biomarker for brain aging, and across the lifespan, this destabilisation correlated with decreased brain activity and cognitive acuity.

Conclusion: The authors concluded that the observed brain network destabilisation may reflect early signs of hypometabolism (reduced metabolic activity) associated with dementia. Therefore, dietary interventions that result in ketone utilisation could “increase available energy and thus may show potential in protecting the aging brain.”

In essence, the stabilisation of brain networks and the increase in energy provided by ketones are presented as mechanisms that counteract the destabiling effects of glucose, which the researchers link to cognitive decline.

The study details are:
Title: Diet modulates brain network stability, a biomarker for brain aging, in young adults

Published Data (on PubMed):
Publication Date: March 17, 2020
Journal: Proceedings of the National Academy of Sciences (PNAS)

PubMed ID (PMID): 32127481
Digital Object Identifier (DOI): 10.1073/pnas.1913042117