Reusing cooking oil may lead to cancer

Frying in the face of good health with old cooking oil
Source: The Standard by Beatrice Siu

Date: Wednesday, February 03, 2010

Cooking oil can be dangerous to your heart and even lead to cancer if you use the same lot over and over again, University of Hong Kong researchers warn.

The Hong Kong Eating Oil Association, which commissioned the research, says households should stop reusing cooking oil.

The survey of 500 people last month revealed 73 percent reused oil after cooking, 29 percent said they would use it two to three times.

More than a quarter use it after storing it for 10 days. Only 6 percent threw it away after using it once.

"Some people reuse the oil for the sake of saving money, and neglect the adverse effect on health," said association chairman Francis Sze Chi- keung. HKU researchers found the peroxide value soared 27 times after deep-frying food and that it continues to grow 8 to 10 percent each day even if stored in covered containers.

Associate professor Edmund Li Tsz-shing said peroxide and saturated fat derived from cooking oil under high temperature could lead to heart disease and cancer.

"Peroxide multiplies the risk of cardiac disease and cancer, while oxidized and polymerized cooking oil damages the liver as well." Li said.

It is better not to reuse cooking oil, particularly with fish and food containing a high amount of animal fat, he said.

Li advised people to use the right amount of high quality oil which provides vitamin A, D, E and K.