Health-y and Oil-y

Krish Kherajani, 3rd Year MBBS, Terna Medical College

Vegetable oil, palm oil, soybean oil, sunflower oil, safflower oil, mustard oil, groundnut oil, sesame oil, coconut oil; whoa hold on, where exactly are we going with this, was my initial reaction when I got to know about the huge number of oils we all consume, without knowing the difference between them. Is there a difference? Oh yes. You must’ve seen those ads where a healthy family consumes Saffola oil, which is being promoted as the best of all, as it lowers your…Cholesterol…Cholesterol is the only word we know about the oils that we consume, but of course there’s much more to it than it seems. Let me break the confusion down for you and also warn you about, how reading this article will make you overthink about the oil you’re consuming at least for the next 2 meals, maybe. (If it’s more than 2, then that’s just how well I write.)

Edible oils have several fatty acids, which can be grouped into three classes–saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA). Trans fatty acids are a subtype of PUFA, which are produced by hydrogenation of vegetable oils-Vanaspati ghee or marine oils. In addition, edible oils contain several antioxidants, phytosterols, and micronutrients.

Saturated Fatty Acids (coconut oil is rich in this- all South Indians are going to regret reading further) have been considered harmful, as they can increase cholesterol (the only word about oils that you knew before this) which is Total Cholesterol (Tc) and LDL cholesterol (aka bad cholesterol). This serves as a risk factor for atherosclerosis or basically fat clogging up your arteries (my pathology teacher strongly disagrees with this definition of atherosclerosis).

However, a recent randomized study and a systematic review (probably done by a South Indian) have shown that, serum lipids were not much altered by coconut oil and that SFA may not be harmful as considered earlier.

Trans Fatty acids (TFA) are considered even worse than saturated fats, as they have undesirable effects on serum lipids, are associated with an elevated risk of CHD(Coronary Heart Diseases) and also possibly other chronic diseases like Alzheimer’s disease, cancer, diabetes, obesity, inflammation, depression, etc.

PUFA and MUFA are other types of fatty acids that can lower LDL cholesterol and are cardio protective.

So which is the healthier one? Which one will protect my heart like I saw in that advertisement?

A healthy oil should have two types of PUFAs, N6 and N3 in the ratio of 5–10:1 or lower to prevent heart disease.

You must’ve heard a lot about olive oil being healthy. In urban households it’s considered healthy as it’s overpriced, but let’s get those facts corrected too: Olive oil does confer beneficial effects on plasma lipid concentrations but brings about a linear reduction in oxidative stress markers. The main limitation is that, olive oil does not have an ideal N6 to N3 ratio and may not be suitable for Indian cooking.

Mustard oil is considered a healthy edible oil because, it is low in SFA, high in MUFA and PUFA (especially alpha-linolenic acid) and has a good N6:N3 ratio (6:5). It is also available in a non-refined (cold compressed) form and is relatively stable during cooking at high temperatures. Several studies also suggest that mustard oil may be associated with a lower CHD risk as compared to other oils. A study reported 71% reduction in CHD risk among individuals using mustard oil for frying as compared to sunflower oil. Another randomized trial has demonstrated that in acute MI (or heart attack) patients using mustard oil, there was reduction in arrhythmias, heart failure, and angina.

Do we even need this knowledge while cooking, especially in an Indian household – if all oils can fry my food, what’s the need of knowing this?

It is important to choose a healthy oil, especially after this pandemic, which resulted in inflation of edible oils by 50-70%, resulting in many Indian households reducing the quality of the cooking oils they use. In the global context, Indian cooking conditions differ greatly. As stir-frying is a routine process in every curry or other similar preparations, the oils are often subjected to high temperatures. As a result, exposure to high temperatures not only destroys antioxidants like vitamin E and β-carotene but also produces toxic compounds that may potentially be mutagenic or atherogenic. It is advisable to avoid refined oils, since during the refining process, oils are heated to high temperatures resulting in their degradation and generation of toxic substances. Refined oils are particularly high in PUFAs, degrade easily and therefore, should be avoided for frying. On the contrary, oils high in saturated fats (like ghee/coconut oil) can be used for Indian cooking, as they are comparatively stable during frying.

The use of unhealthy vegetable oils wasn’t always the norm in Indian cooking. Traditionally, Indians cooked with mustard, groundnut, sesame, and coconut oils. These seeds and nuts are native to India and are known to have high oil content when extracted via cold pressing. Foreign vegetable and seed oils such as palm, soybean, sunflower, and safflower oils were recently imported into India by food and agricultural companies which were eager to make big profits. As a result, the food companies used bogus health claims to advertise their new oil products to the Indian population.

You do want to know the one and only oil that is healthy as well as suitable for cooking right? Here it goes:

While all oils (having low SFAs of course) have some unique benefits and the best one can’t just be pointed at, it does appear that mustard and rapeseed oils – due to their favorable LA/ALA ratio, low SFA, and high MUFA content along with their relative stability during cooking – can be a preferred choice, particularly mustard oil in its non-refined (cold-pressed) form. In fact epidemiologic studies among Indians suggest that mustard oil consumption can reduce the risk of CHD. Further, appropriate blending of edible oils (such as rice bran and safflower oil; coconut and sesame oil; canola and flaxseed oil) also appears to be a good option to reduce the plasma lipids, inflammation and, thus, the CHD risk.

You know it all by now; from which oil to use to what the benefits are of the never-ending list of oils stated above. Now make sure to be conscious of the oil you choose and think at least for the next 2 meals about the oil in your food; if it’s more than 2, you know who to blame…for giving you a healthy lifestyle of course.