New evidence from worms suggests that dieting could be good for the brain. In a new PLOS Biology study, researchers found that dietary restriction improved learning in nematodes, uncovering a possible mechanism for this effect.
Long-term food restriction is thought to increase lifespan in animals by improving cellular health, but it was not clear how such dieting affected brain neuronal pathways. The authors of this study studied the Caenorhabditis elegans nematode and found that food deprivation improved its ability to learn an association between a food source and a smelly chemical called butanone.
The researchers conducted further investigation, using worms that lacked the gene encoding a neuronal regulator. This enabled them to discover a possible mechanism for the effect: restricted access to food may limit the production of kynurenic acid, a metabolite of the amino acid L-tryptophan, which usually inhibits glutamate signalling in the learning pathway. The lack of kynurenic acid therefore increases neuronal activity and so learning.
While dietary restriction likely affects animals via multiple independent pathways, this research suggests that the learning-specific effects can be separated from those acting on other processes, such as aging. Further research could help to elucidate if similar pathways act in humans. So would you give up chocolate to improve your studies?
Image Credit: Hang Ung, Jean-Louis Bessereau laboratory, France
Research Article: Vohra M, Lemieux GA, Lin L, Ashrafi K (2017) The beneficial effects of dietary restriction on learning are distinct from its effects on longevity and mediated by depletion of a neuroinhibitory metabolite. PLoS Biol 15(8): e2002032.https://doi.org/10.1371/journal.pbio.2002032