• Posted March 27, 2024

Could Deep Frying Foods Harm the Brain? Rat Study Suggests It Might

Fried foods not only wreck the waistline, but they could also be harming the brain, a new study of lab rats suggests.

Fed chow that was fried in sesame or sunflower oil, the rodents developed liver and colon problems that wound up affecting their brain health, researchers found.

These brain health effects not only were found in the lab rats that munched down the fried food, but also in their offspring, noted lead researcher Kathiresan Shanmugam, an associate professor with the Central University of Tamil Nadu in India.

These results suggest that reused frying oil could affect connections between the liver, gut and brain, Shanmugam said.

“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,” Shanmugam said. “To our knowledge we are first to report long-term deep-fried oil supplementation increases neurodegeneration in the first-generation offspring.”

Scientists stress that this is early research, however, and animal studies don't always pan out in humans.

The study was presented Sunday at the American Society for Biochemistry and Molecular Biology annual meeting in San Antonio, Texas.

Deep frying adds loads of fat calories to food, researchers noted. In addition, frying oil that's reused often loses many of its natural antioxidants and health benefits, while gaining harmful compounds.

To explore the long-term effects of eating fried foods, female lab rats were divided into groups that ate either standard chow, chow soaked in room-temperature oils, or chow fried in reheated oil.

Rats that ate fried chow developed inflammation of the liver, and their colon microbes began to release more bacterial toxins, results show.

These changes resulted in lower levels of important omega-3 fatty acids being transported to the brain, Shanmugam said.

“This, in turn, resulted in neurodegeneration, which was seen in the brain [tissue] of the rats consuming the reheated oil as well as their offspring,” Shanmugam said in a meeting news release.

As a next step, researchers want to study the potential affects of fried foods on brain diseases like Alzheimer's and Parkinson's, as well as on mood disorders like anxiety and depression.

These results also open new research possibilities into the relationship between gut microbes and the brain, researchers said.

Because these findings were presented at an academic meeting, they should be considered preliminary until published in a peer-reviewed journal.

More information

Harvard Medical School has more on how diet affects the brain.

SOURCE: American Society for Biochemistry and Molecular Biology, news release, March 25, 2024