Who can resist French fries, especially the golden crispy restaurant fries? No one, with ease at least. However, this…guilty pleasure of many seems to have to be limited to special occasions.
Although it is already known that fried foods should be consumed in moderation, due to the high calories and trans fats, a new study highlights the risks for health from reused frying cooking oils. More specifically, the scientists, through a study presented at Discover BMB, the annual meeting of the American Society for Biochemistry and Molecular Biology, and focusing on experiments with mice, found that experimental animals that consumed fried food in already used oil, presented higher levels of neurodegeneration, compared to control animals on a healthy diet. The same pattern, however, was observed in their offspring.
The researchers also found that increased neurodegeneration appears to be linked to the oil’s effects on the two-way communication network between the liver, gut and brain. This liver-gut-brain axis is considered crucial for the regulation of various physiological functions, and its impairment is associated with neurological disorders.
“Frying at high temperatures has been linked to various metabolic disorders, but no long-term research has been conducted on the effect of frying oil consumption and its harmful effects on health. To our knowledge, we are also the first to report that long-term consumption of frying oil increases neurodegeneration in first-generation offspring,” says Dr. Kathiresan Shanmugam, associate professor from the Central University of Tamil Nadu.
The negative imprint
To investigate the long-term effects of consecutively using the same frying oil, the study authors divided one group of female rats into five other groups. Each group received either normal feed alone or feed with 0.1 ml per day of unheated sesame oil, cold sunflower oil, reheated sesame oil or sunflower oil for 30 days. Reheated oils mimicked reused frying oil.
Compared to other groups, rodents fed reheated sesame oil or sunflower oil showed increased oxidative stress and inflammation in the liver. The same rodents also showed marked damage to the colon that caused changes in endotoxins and lipopolysaccharides, toxins released by certain bacteria.
As the researchers explain, “as a result, lipid metabolism in the liver was significantly altered and the transport of the important omega-3 fatty acid DHA to the brain was reduced. This, in turn, led to neurodegeneration, which was observed in the brain histology of rats consuming the reheated oil as well as their offspring.”
Additional experiments involving the addition of monosodium glutamate (MSG) to induce neurotoxicity in the offspring showed that the offspring that consumed the reheated oils showed a higher risk of neuronal damage than the control group that did not consume any form of oil or the mice that consumed the reheated oils. oils that had not been heated.
Although more research is needed, the study authors report that supplementing with omega-3 fatty acids and nutrients such as curcumin and oryzanol may help reduce liver inflammation and neurodegeneration. In order to evaluate their results, however, clinical studies will be needed.