Reusing Oil - Why Is It Lethal?

When we talk about cooking, the first thing that comes to our mind is oil. A lot of oil goes into preparing various lip-smacking Indian cuisines, especially the different types of fried dishes. But what happens to the leftover oil? Many times, the used oil find its way back into the pan, being reused for the preparation of another delicacy, while the approach may be economical, trying to save a few bucks at the cost of your family’s health is not a very wise decision. Reusing the same oil for cooking may have deleterious consequences on the health. In this article, we will discuss why you should refrain from using the same oil for cooking.

1. Research suggests that using the same oil repeatedly leads to the generation of free radicals. The oxidative damage triggered by the free radicals can wreak havoc, giving rise to inflammatory disorders, cardiovascular diseases, and in some cases, even cancer.
2. The free radicals can speed up the skin aging process.
3. In the long run, free radicals may give rise to Parkinson’s Disease or even Alzheimer’s Disease.
4. Every cooking oil comes with a smoke point (a temperature that indicates the breakpoint of an oil). As compared to refined oil, vegetable oil has a relatively higher smoke point. However, when the oil is reused, there is a significant drop in the smoke point. Heating the oil beyond the smoke point can be harmful. The oil undergoes oxidation and releases free radicals along with toxic compounds such as HNE (4-Hydroxy-2-Nonenal).

Things to remember, if as a last resort you have to reuse the same oil for cooking

1. Oil which is used for frying can be used for sautéing or shallow cooking but using the same for deep fried should be avoided. Oil should be cooled before storing. When you're finished frying, turn off the heat as soon as possible and allow the oil to cool down completely before straining. Pour the used oil through a fine-meshed sieve lined with a couple layers of cheese cloth and then finally store it. Not every oil can be refrigerated. Refrigeration makes oil cloudy but it doesn't affect the texture. Before using the refrigerated oil, it should be kept in room temperature.
2. Many times, the used oil is not strained properly before storing. As a result, some of the food particles remain in the oil. If the same is not refrigerated, the oil may facilitate the growth of the bacteria Clostridium botulinum. The toxins produced by this bacteria can give rise to a critical and life-threatening food poisoning condition known as Botulism.
3. Thus, strain the oil with care. Never store (use an airtight container for the storage) hot oil in the fridge. Allow the oil cool first before transferring it into a container.
4. Do not reuse the oil if it has changed its colour or texture. Oil that appears greasy, dark and foul-smelling can harm the body immensely if reused.
5. Oils with a high smoke point such as mustard oil, rice bran oil, sesame oil, sunflower oil can be reused. However, to play it safe, avoid reusing the oil more than twice.
6. Olive oil (especially the virgin and extra virgin oil) comes with a low smoke point and should not be reused.
7. Refrain from reusing refined oil and animal fats as they also have a low smoke point. Though with precaution the oil can be reused in cooking, do not make this an everyday practice. Better to be safe now than to be sorry later.