The information on what oils are the healthiest for Indian (high-heat) cooking is quite conflicting depending on who you ask. However, the two main factors to consider are much simpler:
The smoke point is a temperature range which depends on which the components of oil begin to break down and new undesirable compounds start forming. There’s also the formation of smoke, hence the name. The main compound responsible for the acrid, burnt and piercing smell and flavour is Acrolein, which irritates the skin, eyes, and respiratory tract.
Fatty acid profile
Oils and fats are mainly composed of long-chain fatty acid ester derivatives known as triglycerides, to a much lesser extent diglycerides, monoglycerides and free fatty acids. These triglycerides can be made up of saturated and unsaturated fatty acids. All fats are a mixture of saturated and unsaturated fats. Saturated fats acids are stable (don’t go rancid easily) and have higher melting and smoke points. However, it is widely recognised that their consumption at more than the recommended level (<10% of calories consumed) is a significant risk factor for Cardiovascular and other diseases, including some cancers. Unsaturated fats are less stable and have lower melting and smoke points. However, they are on the other end of the spectrum when it comes to health. They reduce bad cholesterol (LDL) while increasing good cholesterol (HDL), and lower blood pressure, thereby improving cardiovascular health.
Without further ado, here are the healthiest oils to use for Indian (high-heat) cooking:
1. Rice bran oil
Rice bran oil is extracted from rice bran, the outer layer of the rice grain. Like olive oil and avocado oil, it is rich in unsaturated fats and is beneficial for heart health. The Japanese government recognizes this oil as a health food because of its cholesterol-lowering effects. It boasts a staggering 29% of the RDA of Vitamin E in just a tablespoon! Studies show that it helps lower blood sugar levels without affecting insulin levels, reducing insulin resistance and reducing the risk of type-2 diabetes. Several compounds in rice bran oil have antioxidant and anti-inflammatory effects. One of these compounds is Oryzanol, which has been shown to suppress several enzymes that promote inflammation. Another ace up its sleeve is a group of antioxidants known as Tocotrienols, which not only lower inflammation and oxidative stress but may also have anti-cancer properties.
The smoke point is around 230℃.
2. Low Erucic acid Mustard oil
Pure mustard oil contains a large proportion of Erucic acid (a fatty acid), which is why most mustard oil is banned for use in cooking in the EU and US. The problem with Erucic acid is that in many animal studies, it has been shown to cause an accumulation of lipids within the heart, reducing its efficiency to beat.
To tackle this problem, scientists including those in India have developed varieties of mustard that produce very little Erucic acid. So go for Low Erucic acid mustard oil and not regular mustard oil. On the other hand, it has an optimum ratio of omega-3 and omega-6 fatty acids and is low in saturated fats. It possesses powerful antimicrobial properties and may help block the growth of certain types of harmful bacteria. Glucosinolate in mustard oil accounts for antibiotic, fungicidal and cancer prevention qualities. Allyl isothiocyanate which is one of the main contributors to its pungency also alleviates pain in addition to Alpha-Linolenic Acid which is anti-inflammatory.
The smoke point is around 250℃ for pure mustard oil, it could be even higher for the low Erucic variety which is recommended for cooking.
3. Canola oil
Canola (Brassica napus L.) is an oilseed crop that was created in Canada through crossbreeding of the rapeseed plant. The name “canola” comes from “Canada” and “ola,” denoting oil. It is a good source of Vitamins E and K. It has a high percentage of unsaturated fats. It is a good source of the ALA omega-3 fatty acid.
Expeller-pressed Canola oil has a smoke point of 200℃.
Even though it is mostly saturated fat, Ghee is still a good source of omega-3 fatty acids. It is also rich in conjugated linoleic acid (CLA), which, has anti-cancer properties and, may help reduce or control obesity. Its also a good source of Vitamins A, D, K and E. It also contains Butyric acid which lowers inflammation and improves digestive health. Opt for ghee from cow sheds that allow the cow to feed on pasture, grass-fed milk products in general contain higher amounts of vitamins and anti-oxidants as the cows also consume herbs while they graze on grass.
The smoke point is ~250℃.
5. Coconut oil
Coconut oil is exceptionally rich in lauric acid, a rare saturated fat that helps to improve the composition of blood lipids. It is a rich source of antioxidants such as tocopherols, tocotrienols, phytosterols, flavonoids, and polyphenols. Being very rich in Medium-Chain-Triglycerides, it may encourage fat burning, have antimicrobial effects, help reduce hunger, help reduce seizures, boost skin and hair health, and help reduce symptoms of Alzheimer’s disease.
The smoke point is ~177℃ for the unrefined and ~205℃ for the refined kind.
Of the oils mentioned above, Rice bran and Canola oil are the most neutral in flavour and so can be used in every dish. Mustard oil and Unrefined coconut oil are the least neutral, but pair well with traditional dishes. One very big myth is that oil used once for frying should not be used again; it can be used up to 5 or 6 times, after filtering each time, provided that that the oil did not smoke.