Over two decades, information has been fed to us by experts that vegetable oil is relatively healthy compared to frying in ghee, butter or animal fat. The reason stated was the high amount of saturated fats present in the latter. A new research suggests that vegetable oils may not be as healthy as previously thought. This is because some vegetable oils are rich in polyunsaturated fats which have the potential to turn into toxins. Corn and sunflower oil are the biggest culprits in this regard.
Any oil that is subject to high heat goes through the process of oxidation. The reaction with oxygen in the air results in the formation aldehyde and lipid per oxide. The rate of this reaction depends upon the amount of polyunsaturated fat in oil.
Professor Martin Grootveld explains that these polyunsaturated fats at frying temperature go through change in molecular structure and the formation of Aldehydes is accelerated.
The indigestion or inhalation of even small amounts of Aldehyde has been linked with heart disease and cancer.
On the other hand, there are oils which are rich in monosaturated and saturated fatty acids. These include olive oil, coconut oil and cold pressed rape-seed oil. Their composition makes them relatively stable at high heat (temp 180 °C) frying temperatures.
Oils when used in conjunction with starchy foods can be doubly dangerous. Fried rice, French fries, croutons etc. can be extremely unhealthy because heating starchy food (at temperatures above 120 °C) creates acrylamide which has been also identified as a potential carcinogen.
What to do?
- Cook at low temperatures if possible.
- Do not reuse cooking oil
- Keep the oil in the cupboard, away from light
- Minimize the use of oil and remove extra oil on food using kitchen towels
- Try to eat raw wholesome food
- Use coconut oil or virgin oil
- Eat moderate and balanced diet
A list of oils and their typical fat content is present below.
|Type of oil or fat||Saturated (%)||Polyunsaturated (%)||Monounsaturated (%)|
So next time you pick up a plate of biryani, remember the key word “moderation”