It Is Better To Never Again Reuse The Frying Oil.

Scary and Astonishing Hazards of Re-Using the Frying Oil

Deep-fried oils have been associated with inflammation and oxidative stress, risk factors for neurological illnesses and other chronic ailments.

A recent study on rats has revealed a possible connection between prolonged ingestion of repurposed deep-fried oil and elevated neurodegeneration, amidst the escalating neurodegenerative health issue.

According to the latest study, rats given meals that included reheated frying oils showed noticeably more neurodegeneration than rats given a regular diet.

The research suggests that heated oil could exacerbate neurodegeneration by disrupting the liver-gut-brain axis, a system known to be associated with neurological disorders and crucial for maintaining physiological balance.

Cooking oils: heated or unheated

Deep-frying is a widely used cooking technique in many parts of the world, including homes, street sellers, and fast-food establishments.

Studies have linked the consumption of deep-fried meals to certain malignancies and cardiometabolic disorders. Dr. Kathiresan Shanmugam, PhD, an associate professor at the Central University of Tamil Nadu in Thiruvarur, India, directed the research team investigating this matter.

For a duration of thirty days, the research team divided the female rats into five groups and fed them either a standard diet (control group) or a standard diet supplemented with reheated sunflower oil, reheated sesame oil, or reheated sesame oil every day.

This method was created to simulate the effects of reusing deep-frying oil.
Rats fed diets containing warmed oils showed increased oxidative stress and inflammation in their liver tissues when compared to their peers on alternative diet regimens.

These rats also showed evidence of substantial colonic injury, with changed levels of lipopolysaccharides suggesting the presence of toxins produced by certain strains of bacteria.
Follow-up studies used monosodium glutamate (MSG) to increase offspring neurotoxicity. Compared to the control group fed either no oils or diets with unheated oils, the offspring fed diets containing reheated oils exhibited a higher vulnerability to neural injury.

Reheated oil consumption also caused specific brain damage, particularly in regions of the brain that are important for regeneration, underscoring the neurological risk associated with reheated oil consumption.

Rats given unheated oils, on the other hand, displayed superior brain health markers than rats given reheated oil groups.

How does reheating alter the chemical composition of oils?

High temperatures drastically change the natural chemical structure of oils, lowering their antioxidant content and producing dangerous substances like acrylamide, aldehydes, and trans fats.
This process is made worse by reheating oils, particularly those used for deep-frying, as the oil loses its health benefits and produces more pollutants each time it is used.

Oxidative stress in the brain, which may cause neuronal damage and increase the risk of neurodegenerative diseases, can be brought on by an imbalance between reactive oxygen species (ROS) and biological antioxidants.

Furthermore, reheated frying oils contain oxidised lipids and advanced glycation end products (AGEs), which have been connected to a number of chronic illnesses, including neurological disorders.

Dr. Alexandra Filingeri, a clinical nutritionist and registered dietitian who was not associated with the research, concurred and expounded upon the detrimental consequences of warming cooking oil on its nutritional value.

Cooking oil’s fatty acid composition is adversely affected by repeated heat exposure, which increases trans isomers and saturated fatty acids while decreasing health-promoting polyunsaturated fats.

What potential health effects might heated oil consumption have?

Reheated oils have been connected to elevated levels of inflammation and cholesterol, which are risk factors for neurological diseases and cardiometabolic diseases, though additional research is required.

The organ responsible for filtering and detoxifying toxins in our bodies, the liver, may be especially susceptible to harm from heated oils.

Recurrent exposure to high temperatures can damage the lipid metabolism of the liver, increasing the risk of nonalcoholic fatty liver disease (NAFLD) and oxidative stress on the liver brought on by reactive oxygen species (ROS).

Furthermore, oxidised fats have an impact on the gut microbiota and may cause inflammation, dysbiosis, and disruption of the gut barrier, according to Simpson and Filingeri. 

Filingeri emphasised that preserving a balanced gut microbiome is critical for liver function since disruptions may allow pathogenic bacteria to enter the liver through increased intestinal permeability, resulting in oxidative stress and inflammation.

Through its metabolic, immunological, and hormonal communication channels, the liver-gut-brain axis is essential for neurological health. Simpson claims that this disruption may result in neuroinflammatory diseases and neurological illnesses.

Simpson went on to explain that abnormalities in the metabolism of particular lipids may impair neuronal activity and communication in the brain.

Nutritional strategies to prevent neurodegeneration

Diets high in omega-3 fatty acids and nutraceuticals such as curcumin and vitamin E—found in foods like turmeric and almonds—can help lessen the negative effects of reheated oil consumption.

Simpson claims that consuming antioxidants, fibre, and polyphenols from nuts, vegetables, fruits, and green tea can lessen inflammation and oxidative stress, which will protect the brain.

Filingeri also stressed the value of probiotics from foods like kimchi and kefir for the health of the liver and intestines.

Neurodegeneration may be avoided by adhering to generally healthy eating regimens like the MIND or Mediterranean diets.

Conversely, eating fried food frequently raises the chance of developing chronic diseases by promoting weight gain, insulin resistance, and metabolic syndrome.

According to a study, the quality of the oils used before they are heated is important while cooking.

It is recommended that consumers choose cooking oils with a high content of polyunsaturated fats and prepare food at low heat. Cooking oils should not be heated to high temperatures or used again for subsequent cooking sessions.

In order to avoid overheating and excessive oxidation, deep-frying enterprises should rotate their cooking oils and keep an eye on the oil’s temperature.

The experts advised customers to choose dishes cooked using healthier techniques like grilling or baking and to inquire about the cooking oils used in restaurants in order to further avoid hazardous oils.

Diet and the risks of neurodegeneration

According to this new research, consuming warmed oils on a frequent basis may impair liver function and raise oxidative stress, which increases the risk of neurodegenerative disorders.

Despite the fact that this study was done on rats, the findings support careful food selection and draw attention to potential health risks associated with reheated oil consumption.