Repeatedly heated cooking oils may cause cancers

Islamabad : Repeatedly heated cooking oils (RCO) generate number of compounds including polycyclic aromatic hydrocarbons (PAH) and a toxin called 4-hydroxy-trans-2-nonenal (HNE) that have been reported as carcinogenic and associated with increased chances of cardiovascular diseases, stroke, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, various liver disorders and cancer.

Various studies have revealed that not only food processed in RCO but also inhalation of cooking fumes can pose serious threats to health while regular consumption of RCO has been associated with many malignancies including lung, colorectal, breast, and prostate cancers. Once absorbed in the body, HNE reacts with DNA, RNA and proteins affecting basic cellular processes.

A number of health experts expressed to ‘The News’ that the consumption of food in again and again reheated cooking oil may expose one to high levels of toxic aldehydes, chemicals known to cause neurodegenerative disease and cancer.

The best quality of edible oil when heated repeatedly releases toxic chemicals and ‘Iftar’ dishes like ‘pakoras’, ‘samosas’, ‘kachoris’, ‘jalebis’ etc. fried in RCO can cause heart problems, breast and prostate cancers along with a number of other health threats, said Consultant Intensive Care Medicine at Pakistan Institute of Medical Sciences Dr. Muhammad Haroon while talking to ‘The News’.

He added the practice of using repeatedly heated cooking oil is very much common particularly at commercial level as it reduces the cost of food preparation. Studies have revealed that prolonged consumption of the repeatedly heated oil can increase blood pressure and total cholesterol, cause vascular inflammation as well as vascular changes which predispose to atherosclerosis, a disease in which plaque builds up in arteries, he said.

Rancid meaning old and stale oil contains free radicals and molecules that damage cells in the body and lead to increased risk of various cancers, said medical specialist Dr. Muhammad Sohail Tariq.

A study published recently, in 2019, has revealed that the consumption of RCO and its fumes cause the high incidence of genotoxic, mutagenic, tumorogenic and various cancers.

Dr. Sohail said there is a need to provide an insight and awareness to the general public on the consumption of RCO that is certainly detrimental to health.

He like many other health experts said use fresh cooking oil each time or reuse it only until it gets rancid. Using fresh oil each time may not be practical from economic standpoint so one should try to keep it radicals and bacteria free while storing, he said.

He said if used oil is not properly strained and stored after it cools, bacteria feeds on food particles left in the oil. If well-strained, properly stored and not overheated on first use, most oils may be safe to reuse but if it starts giving smoke on reheating, it should be discarded, he said.