Let me start with a small clarification before we start the actual discussion. If you read the title carefully, this article is going to be very focussed. We’ll talk about cooking, and not about other uses of edible oils such as in salads and pickles. We’ll also limit the discussion on Indian-style cooking – traditional cooking in which some or all foodstuff is fried in oil, butter or clarified butter (ghee).
Here we go!
In a typical Indian dish, say, a vegetable curry, the oil (let that include any type of fat) is heated on a pan at a high temperature. Onion, garlic, ginger, tomato and a number of spices are fried until they turn dark yellow or brown. The main stuff is then put on this deep-fried spice-mix and cooked. There are a million variations of this, but the point to note is that cooking in our homes starts with oil. In some dishes, oil is used for tempering the food. In North Indian dialects, this practice has several popular names such as chhaunk, tadka and baghar.
Most of Indian street food and fast-food needs frying. A lot of oil and ghee go in preparation of sweet dishes.
Most of the fat used in cooking is either unsaturated fat (mostly oils) or saturated fat (e.g. ghee, butter, palm oil, coconut oil). The former is liquid at room temperature and the latter is solid or semi-solid.
Let us refresh our scientific knowledge about edible fats before examining which oil is best suited for cooking purposes. That will remove smokescreen from many jargons used by health experts and oil companies.
The not-so-fat science behind edible fats
All fats in animals and plants are made up of a molecule of glycerol (an alcohol) and three molecules of a type of acids known as fatty acids. That is why fats are called tri-glycerides.
This term ‘tri-glyceride’ is often used in blood reports along with the term ‘lipid’. Broadly speaking, these refer to fat in the blood.
The fatty acids are of numerous types, and these determine all the different qualities of fats and oils.
These tri-glycerides are made up of a big number of Carbon, Oxygen and Hydrogen atoms. These atoms are joined together with ‘bonds’. Bonding among Carbon atoms make the backbone of the fatty acid, with Oxygen coming mostly at the end. This leaves one or two free bonds on the sides of Carbon atoms, which are utilized by Hydrogen atoms to bond with the Carbon chain. One very important factor that separates fats is whether the bonds can take more Hydrogen atoms or all the bonds are ‘saturated’ with Hydrogen atoms. When there is no scope of more Hydrogen atoms, the fatty acid (and the resultant fat) is called saturated, and when there are bonds that could have taken Hydrogen but have not, the fatty acid is called unsaturated.
An unsaturated fatty acid can have a single place where a Hydrogen atom could be accommodated, and such fatty acid is called Mono Unsaturated Fatty Acid (MUFA), and where many such places exist within the fatty acid molecule, such fatty acid is called Poly Unsaturated Fatty Acid (PUFA).
We also come across another set of jargons: Omega 3, Omega 6 and Omega 9. In an unsaturated fatty acid, the location where the lack of saturation occurs can vary. Omega 3 means the unsaturated bond is located 3 places away from the end of the fatty acid molecule. Omega 6 and Omega 9 fatty acids get their name in a similar manner. Omega 3 and Omega 6 belong to PUFA category while Omega 9 comes under MUFA.
You must have noticed that when we keep raising the temperature of oil in the pan, it starts giving smoke. The temperature at which this happens is called the smoke point of that oil/ fat. What happens at the smoke point of an oil/ fat is that its molecules break down due to high heat, and result in small ones, some of which spread in the air in the form of smoke. The smaller molecules that remain in the oil are often harmful to our health. So, oils and fats that have a high smoke point (that means, they will remain stable when heated to a very high temperature) are good for cooking, especially Indian-style cooking. Generally speaking, saturated fats and refined oils have a higher smoke point.
Generally speaking, saturated fats tend to line the inner walls of arteries and thus cause heart attack and stroke. They are, therefore, dubbed as bad fats. On the other hand, unsaturated fats are known as good fats. Research over the years has shown that such branding of oils/ fats as good and bad is an over-generalization. While the hydrogenated fat (vanaspati ghee), which is made in factories by exposing oils to Hydrogen, is definitely harmful, some other types of saturated fats may not be that bad. Similarly, excess of good oils/ fats may also lead to health issues.
Among unsaturated fats, initially MUFA was considered much better than PUFA. Among PUFA oils, Omega 3 was considered much better than Omega 6. Though these notions are still valid, research has found advantages and disadvantages of all such categories of fats/ fatty acids. Experts now recommend using a mix of MUFA and PUFA, and Omega 3 and Omega 6, with a bias in favour of Omega 3 fats.
There comes the rogue fat, called trans-fat. In this type of fats, a separate type of bond (called trans bond) happens as compared to other fats. This changes the geometry, and consequently the biochemistry, of these fats/ fatty acids. Trans-fats occur in a very small quantity in vegetable oils, but are found in animal/ dairy fats. However, these are generated in large quantities when hydrogenated oils (vanaspati ghee) are prepared. These are quite harmful to human health.
Indian traditional oils, ghee and new types of oils – which are the best for Indian cooking?
Indian oils and desi ghee have been demonized by the mainstream medical science and vested interests for decades as bad cooking mediums with undesirable chemicals and bad types of fatty acids. For example, mustard oil’s erucic acid was said to be extremely harmful to the body, coconut oil’s high concentration of saturated fats was said to be harmful to the heart, desi ghee was branded as one of the worst edible fats just because it is composed of saturated fatty acids.
For the sake of brevity, let me not go into the details of sustained campaigns orchestrated by vested interests to vilify traditional oils and ghee, in which doctors have been a willing accomplice. Nevertheless, let me share that such campaigns have led to malnutrition and avoidable diseases in Africa and South Asia, as people discarded traditional oils in favour of hydrogenated oils and refined oils. Those who could afford ghee stopped touching it under a false notion that oils and fats other than imported ones with fancy names and tags were harmful to the body.
The truth is that oils and fats are necessary for human health. Some fats come from foodgrains, nuts, and other plant products but that is not enough for a balanced diet. Non-vegetarians and those consuming dairy products tend to get sufficient fat from animal sources. Thus, the need for additional oils/ fats depends on one’s diet. This also depends on many other factors such as the state of health, level of physical work/ exercise, and age. In the case of women, the body needs more fat during pregnancy and breast-feeding.
Which oil should you use for cooking?
Having discussed the general aspects of edible oils, let us quickly examine the suitability of Indian cooking oils and a few other relevant aspects:
* Most of the traditional Indian oils have high smoke point, and are, therefore, good for frying, etc. However, when they are not properly cleaned (for example, kachchi ghani mustard oil, locally extracted cold-pressed oils, raw coconut oil). these oils can smoke quickly due to suspended impurities and other chemicals.
* Mustard oil has some pungent smelling chemicals, and one of them – erucic acid – is found to be harmful when taken in large quantities. Therefore, taking mustard oil in normal cooking is safe, but it is advisable to avoid using it in large quantities. Mustard oil has some other chemicals that are good for human health.
* Common oils such as mustard oil, groundnut oil and coconut oil have a good mix of PUFA and MUFA.
* Coconut oil has some saturated fats (that is why it solidifies during winters), but these are generally of good type. This oil also has some beneficial chemicals.
* We should not be too concerned about the detailed composition of an oil unless suffering from a health issue relating to heart/ circulatory system or brain. A common-sensical approach, supported by research, is to use more than one type of oil.
* Research has established that Desi ghee is good for human health due to its good fats and also some other useful constituents. However, like other common fats/ oils, it needs to be consumed in moderate quantities, and taken with doctor’s advice when suffering from diseases of the circulatory system or having a bad lipid profile (as diagnosed through blood test).
* In some preparations, especially in shops and food industries, oil/ ghee are repeatedly heated (e.g. for frying jalebis, samosas, tikkis, chips and French fries). Such recycled oil is found to be harmful to health.
* Among new/ imported oils, olive oil is supposed to be the best, with high concentration of MUFA fatty acids. However, with a very low smoke point, it is not good for deep frying, etc.
* Canola oil, which is sold at a high price, is very similar to mustard oil but with no pungent smell. Canola literally means Canadian oil, and is extracted from a type of mustard grown in Canada.
* Rice bran oil is also good for Indian cooking, having a high smoke point. It has a chemical called oryzanol, which is found to have some beneficial properties.
* Palm oil, mostly imported from Malaysia and Indonesia, has high percentage of saturated fatty acids. It is very popular in industrial/ commercial cooking because of low price and very high smoke point.
* Soybean oil, sunflower oil and safflower oil have a high smoke point. These have a mix of PUFA and MUFA fatty acids. Out of PUFA, these have a higher concentration of Omega 6 fatty acids, which can lead to swelling if consumed in large quantities. Therefore, it is better to use these oils along with other oils that have a better mix of different types of unsaturated fatty acids, especially Omega 3.
* Refined oils are not good, but there is a catch. The expression ‘refined oil’ is commonly used for cheap oils that have been heavily refined. Such refining uses chemicals also. So, such oils need to be avoided. However, all oils need some level of refining because raw oils have many chemicals, impurities and germs and do not have a high shelf life.
* Hydrogenated oils (vanaspati ghee) should be avoided as much as possible. It is too much refined, is saturated and also has trans-fats.
* Trans fats must be avoided as much as possible. Packed snacks and cooked foods have been mandated to mention the quantity of trans fat in them.
* There is a parallel industry of adulterated oil/ ghee production. As they use cheap raw materials and processes, they have a high profit margin and thus dominate rural and semi-urban markets. They also have no regard for hygiene and various food-safety standards. Therefore, we must be careful in buying oils/ ghee. We do not know whether a popular brand is selling spurious oil or ghee, or is not maintaining quality standards, but the chances of admixing/ adulteration are high in oils/ ghee that are being sold without proper packing, packed but unbranded oil and oil of fly-by-night brands.
The last drop!
All things considered, Indian oils are good cooking medium for Indian style cooking. Oils and fats are essential for overall health, but should be consumed in moderation. Experts advise that we continue to include desi ghee in our diets. If possible, we may include two or more types of oils in our cooking regimen.
When it comes to street food and fast food, we usually consider them bad due to not maintaining hygiene. We consider cooked food in packets, snacks and industrial food bad due to blank calories. I request you to avoid them for another, bigger, reason: use of sub-standard oils, re-use of oils and high quantities of trans fats.
In July 2023, WHO has updated its guidelines on consumption of oils and fats. You can download the guidelines (mind it, these are bulky documents) from these links: (1) Saturated fatty acid and trans-fatty acid intake for adults and children and (2) Total fat intake for the prevention of unhealthy weight gain in adults and children
अगर आप खाना पकाने के तेलों के बारे में सरल हिंदी में निष्पक्ष राय जानना चाहते हैं तो यूट्यूब पर ऐसे एक विडिओ का लिंक यहाँ दिया है, उसे देखें: https://www.youtube.com/watch?v=shl5tWw720Y
*Manoj Pandey is a former civil servant. He does not like to call himself a rationalist, but insists on scrutiny of apparent myths as well as what are supposed to be immutable scientific facts. He maintains a personal blog, Th_ink