A new study found higher levels of neurodegeneration in rats that consumed reused deep-fried cooking oils and their offspring compared to rats on a normal diet. Deep frying, which involves completely submerging food in hot oil, is a common method of food preparation around the world.

Results from the study also suggest that the increased neurodegeneration is tied to the oil's effects on the bidirectional 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 has been associated with neurological disorders.

Kathiresan Shanmugam, an associate professor from Central University of Tamil Nadu in Thiruvarur, led the research team.

"Deep-frying at high temperatures has been linked with several metabolic disorders, but there have been no long-term investigations on the influence of deep-fried oil consumption and its detrimental effects on health," said Shanmugam, formerly at Madurai Kamaraj University, Madurai. "To our knowledge we are first to report long-term deep-fried oil supplementation increases neurodegeneration in the first-generation offspring."

Sugasini Dhavamani, a research collaborator from the University of Illinois at Chicago, will present the research at Discover BMB, the annual meeting of the American Society for Biochemistry and Molecular Biology, which will be held March 23–26 in San Antonio.

Deep frying food not only adds calories; reusing the same oil for frying, a common practice in both homes and restaurants, removes many of the oil's natural antioxidants and health benefits. The oil that is reused also can contain harmful components such as acrylamide, trans fat, peroxides, and polar compounds.

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