A new study finds that cooking drained onion and garlic may be harmful to your heart. Read on to understand how.
Cooking garlic and onion in vegetable oil at high temperatures can generate trans fatty acids (TFAs) and may be harmful to heart health, says a study by Japanese researchers. TFAs are harmful fats that can build up along the walls of your arteries, restricting blood flow and increasing the risk of heart attacks.
While TFAs are typically present in processed foods, evidence suggests they can also be created at home during cooking. Studies indicate that unsaturated fatty acids (FFAs), generally considered beneficial, can undergo transisomerization, a molecular reconfiguration that transforms them into UFAs when heated to 150 degrees Celsius or higher.
To explore this, researchers from Meijo University evaluated the role of isothiocyanates and polysulfides (sulfur-containing compounds found in vegetables such as garlic, leeks, onions, chives and shallots) in promoting the transisomerization of the vegetable UFA during cooking.
The team first evaluated the effects of sulfur compounds on triacylglycerols (TAG) in a model system using reagents. They then tested garlic, onion, leek, cabbage, horseradish, broccoli sprouts, and vegetable oils such as soybean and olive oil to simulate real cooking processes.
The results, published online in the journal Food Research International, showed that sulfur compounds significantly promote heat-induced transisomerization of UFAs in vegetable oils. This occurs especially when cooking temperatures exceed 140 degrees Celsius.
Furthermore, the team also evaluated the role of antioxidants such as alpha-tocopherol in reducing the isomerization of UFA into triglycerides such as triolein and trilinolein.
Although the addition of antioxidants significantly reduced the promotion of isomerization of UFAs by isothiocyanates, they did little to inhibit the promotion of isomerization by polysulfides.
“This explains why cooking vegetables rich in polysulfides, such as garlic and onion, in vegetable oil at high temperatures can generate TFA. The study demonstrates that garlic and onion significantly promote the transisomerization of UFAs,” said the team led by Dr. Masaki Honda from Meijo University.
On the other hand, the release of TFA under normal cooking conditions is minimal.
“Cooking with ingredients rich in natural sulfur compounds may increase the risk of trans fatty acid intake,” the researchers said.
According to the World Health Organization (WHO), TFA are responsible for more than 278,000 deaths annually worldwide. The global health body recommends that consumption of trans fatty acids be limited to less than 1 percent of daily energy intake.
(Except for the header, no changes have been made to the content taken from the IANS agency)
