Long-term consumption of fried oil can lead to neurodegeneration

 A new study found that rats that ate too much fried oil and their offspring had higher levels of neurodegeneration than rats that ate a normal diet.

Research also suggests that increased neurodegeneration is linked to the effects of oils on the two-way communication network between the liver, gut and brain. The liver-gut-brain axis plays a crucial role in regulating various physiological functions, and its dysregulation is associated with neurological diseases. Researchers from the University of Illinois at Chicago presented the results at the annual meeting of the American Society for Biochemistry and Molecular Biology held from March 23 to 26.

Frying, the complete immersion of food in hot oil, is a common food preparation method around the world. To explore the long-term effects of repeated use of frying oil, the researchers divided female rats into five groups. Each group received only standard food and 0.1 ml of unheated sesame oil/unheated sunflower oil/reheated sesame oil/day. Standard food reheated with sunflower oil for 30 days. Reheating oil is designed to simulate reused frying oil.

Rats that consumed reheated sesame or sunflower oil had increased oxidative stress and inflammation in their livers compared to the other groups. The rats also showed severe damage to their colons, resulting in changes in endotoxins and lipopolysaccharides (toxins released by certain bacteria). As a result, liver lipid metabolism is significantly altered and transport of the important omega-3 fatty acid DHA in the brain is reduced. This in turn led to neurodegenerative changes that were observed in the brain tissue of rats that consumed reheated oil and their offspring.

Other studies using MSG to induce neurotoxicity in offspring have shown that offspring consuming reheated oil were more likely to develop neuronal damage than controls that received no oil or those that received unheated oil.

Researchers say supplementing with nutraceuticals such as omega-3 fatty acids, curcumin and oryzanol may help reduce liver inflammation and neurodegenerative changes. They added that clinical studies in humans are needed to assess the adverse effects of consuming fried foods, particularly those made with reused oils.

Next, the researchers hope to study the effects of refried oil on neurodegenerative diseases such as Alzheimer's and Parkinson's disease, as well as anxiety, depression and neuroinflammation. They also want to further explore the relationship between the gut microbiome and the brain to identify potential new ways to prevent or treat neurodegenerative diseases and neuroinflammation.