Wednesday Feb 17, 2016 (foodconsumer.org) -- A growing body of evidence suggests that fructose can be a risk factor for neurodegenerative diseases such as dementia because it is involved in the formation of harmful compounds called advanced glycation end-products (AGEs), according to a study reported by researchers at University of Turin in Turin, Italy. 

Increased consumption of fructose in the West has been associated with cognitive impairment in previous studies.  The study published recently in Neurobiology of Disease explained how fructose can harm the brain and what can be used to prevent the neurodegenerative effect of fructose, particularly on hippocampus.

The study found mice fed a diet with 60% fructose for 12 weeks had increased carboxy methyllysine (CML), the most studied AGE.   CML was found to alter mitochondrial respiratory complexes activity, trigger reactive gliosis, increase oxidative stress and induce early signs of neurodegeneration in hippocampus. 

In the meantime, the fructose containing diet through increased CML led to the translocation of the glutathione-dependent enzyme glyoxalase (Glo-1), the main AGEs-detoxifying system, from axon toward the cellular body of pyramidal neurons.

CML accumulated in mice fed the fructose diet.   Although the detoxifying enzyme Glo-1 was increased, its activity due to the fructose-induced oxidative stress from CML accumulation was not boosted accordingly to prevent CML from accumulating.  Because of CML accumulation, the detoxifying enzyme Glo-1 failed to prevent the neuronal alterations.

The study also tested a chemical called pyridoxamine, which is marketed as a dietary supplement, and found this supplement can completely prevent "all the fructose-induced hippocampal alterations".

Fructose is found in sucrose and high fructose corn syrup.  Other studies have linked fructose consumption to increased risk for obesity, cardiovascular disease and cancer.

Raffaella Mastrocolaa , Debora Nigroa, Alessia S. Centoa, Fausto Chiazzab, Massimo Collinob, Manuela Aragnoa, High-fructose intake as risk factor for neurodegeneration: Key role for carboxy methyllysine accumulation in mice hippocampal neurons, Neurobiology of Disease, Volume 89, May 2016, Pages 65–75