Robert Mendick
Vegetable oil could be one of the most unhealthy cooking oils.
Cooking with vegetable oils releases toxic chemicals linked to cancer and other diseases, according to leading scientists, who are now recommending food be fried in olive oil, coconut oil, butter or even lard.
The results of a series of experiments threaten to turn on its head official advice that oils rich in polyunsaturated fats – such as corn oil and sunflower oil – are better for the health than the saturated fats in animal products.
Scientists found that heating up vegetable oils led to the release of high concentrations of chemicals called aldehydes, which have been linked to illnesses including cancer, heart disease and dementia.
Martin Grootveld, a professor of bioanalytical chemistry and chemical pathology, said that his research showed “a typical meal of fish and chips”, fried in vegetable oil, contained as much as 100 to 200 times more toxic aldehydes than the safe daily limit set by the World Health Organisation.
In contrast, heating up butter, olive oil and lard in tests produced much lower levels of aldehydes. Coconut oil produced the lowest levels of the harmful chemicals.
Professor John Stein, Oxford’s emeritus professor of neuroscience, said that partly as a result of corn and sunflower oils, “the human brain is changing in a way that is as serious as climate change threatens to be”.
Because the vegetable oil is rich in omega 6 acids, it is contributing to a reduction in critical omega 3 fatty acids in the brain by replacing them, he believes.
“If you eat too much corn oil or sunflower oil, the brain is absorbing too much omega 6, and that effectively forces out omega 3,” said Professor Stein. “I believe the lack of omega 3 is a powerful contributory factor to such problems as increasing mental health issues and other problems such as dyslexia.”
He said sunflower oil and corn oil were now banished from his own kitchen, replaced by olive oil and butter.
Professor Grootveld, of De Montfort University in Leicester, who carried out a series of experiments, said: “For decades, the authorities have been warning us how bad butter and lard was. But we have found butter is very, very good for frying purposes and so is lard.
“People have been telling us how healthy polyunsaturates are in corn oil and sunflower oil. But when you start messing around with them, subjecting them to high amounts of energy in the frying pan or the oven, they undergo a complex series of chemical reactions which results in the accumulation of large amounts of toxic compounds.”
Health concerns linked to the toxic by-products include heart disease; cancer; “malformations” during pregnancy; inflammation; risk of ulcers and a rise in blood pressure.
Saturated fats, including butter, ghee and coconut oil are a healthier option.
Stay Healthy.