I saw this post at the Extreme Longevity website: How Caloric Restriction Regulates DNA...
When calories are scarce, cells in the body shift to metabolizing fat instead of glucose. When fatty acids are broken down for energy, ketones are produced, chief among them beta-hydroxybutyrate (bOHB).
[Research] has shown that ketone bodies activate a cell switch called Fox03a, which is known to regulate lifespan in a beneficial manner.
The current study looked at the effects of bOHB on oxidative stress and histones within cells.
They demonstrated that bOHB directly inhibits the class I histone deacetylase (HDAC). This was found to occur both if bOHB was added to cells or if the cells were calorically restricted. bOHB globally increased histone acetylation.
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I wouldn't think this means we should necessarily be supplementing beta-hydroxybutyrate, though that might be an option. (hydroxybutyrate acts to deactivate ROS, which is not desireable under all cirumstances, as in the case of certain cancers.) It might also explain some of the benefits of low carb diets.... the Atkins style diets generate keytone bodies, and assumedly beta-hydroxybutyrate.
