Seed Oil Panic: What Indian Cooking Oils Like Mustard, Coconut and Sesame Actually Do to Your Health

The claim, stripped of its more dramatic versions, goes like this: industrially processed vegetable oils, sunflower, soybean, canola, corn, are high in omega-6 polyunsaturated fatty acids, particularly linoleic acid. When omega-6 intake dwarfs omega-3 intake, the body's inflammatory pathways tip out of balance. A 2021 review in Prostaglandins, Leukotrienes and Essential Fatty Acids, led by researcher James DiNicolantonio, found that modern Western diets carry an omega-6 to omega-3 ratio as high as 20:1, against an estimated ancestral ratio of 4:1 or lower. Chronic low-grade inflammation is linked to cardiovascular disease, insulin resistance, and metabolic syndrome.
That core biochemistry is not wrong. What gets wrong is the next step: collapsing all cooking oils into a single category called "seed oils" and treating them as uniformly dangerous. That move erases a distinction that matters enormously to Indian kitchens.
Mustard oil has an omega-6 to omega-3 ratio of roughly 2:1, one of the most balanced profiles among common cooking fats. A 2004 study published in the American Journal of Clinical Nutrition by Rastogi et al. found that populations in North India using mustard oil as their primary fat had lower rates of coronary artery disease than those using vanaspati or refined soybean blends. Cold-pressed mustard oil also contains allyl isothiocyanates, the same compounds that give it its pungency, which have demonstrated antimicrobial properties in laboratory studies.
Coconut oil is predominantly saturated fat, lauric acid specifically, which raises both LDL and HDL cholesterol. The net cardiovascular effect is contested, but what is not contested is that coconut oil does not carry the omega-6 load that makes industrial seed oils problematic. It is thermally stable at high temperatures, which matters for Indian cooking methods that involve sustained high heat.

Sesame oil, particularly the cold-pressed variety used in South Indian cooking and in Ayurvedic preparations, contains sesamol and sesamin, lignans with antioxidant properties. Its omega-6 content is higher than mustard oil, but the presence of these natural antioxidants appears to slow oxidation during cooking. A 2016 study in the Journal of Medicinal Food found sesame oil consumption associated with reductions in oxidative stress markers in patients with type 2 diabetes.
Refined oils, whether derived from sunflower seeds, soybeans, rice bran, or even coconut, go through processes that matter: bleaching, deodorising, and in some cases hydrogenation. These steps remove natural antioxidants, strip flavour compounds, and in the case of partial hydrogenation, generate trans fats. India's consumption of refined vegetable oils has risen sharply since the 1990s, tracking the global shift toward processed cooking fats. The ICMR-NIN dietary guidelines for Indians recommend keeping total fat intake to 20 to 30% of calories and specifically flag refined oils high in omega-6 as a concern when consumed in large quantities.

The problem the panic correctly identifies is not the seed. It is what industrial refining does to the oil before it reaches your pan. A bottle labelled "refined sunflower oil" shares almost nothing nutritionally with cold-pressed sunflower oil. The panic conflates them, but the distinction is the entire argument.
Every cooking fat degrades under heat. The relevant variables are smoke point, degree of saturation, and whether the oil is reused. Polyunsaturated fats, the category that includes most refined vegetable oils, oxidise faster at high temperatures, producing aldehydes and other breakdown compounds. A 2015 study by researchers at De Montfort University, published in the journal Acta Scientific Nutritional Health, found that sunflower oil produced significantly higher levels of aldehydes when heated to frying temperatures than butter or coconut oil.

Traditional Indian cooking practices intuitively matched oil to method. Mustard oil, with its relatively high smoke point and balanced fat profile, was used for high-heat tadkas. Sesame oil was added after cooking or used in lower-heat preparations. Coconut oil was used in coastal cuisines where the cooking style suited its properties. The problem is not that these oils were wrong. The problem is that refined oils displaced them without any corresponding adjustment in cooking method.
The seed oil panic, at its most useful, is a prompt to read labels and think about processing. Cold-pressed oils, mustard, sesame, coconut, groundnut, retain their natural antioxidants and fat profiles. They cost more. They also behave differently in the pan, and for Indian cooking methods, they generally behave better.
Avoiding all seed oils is not the point. Avoiding refined oils that have been stripped of their protective compounds, used at temperatures above their smoke point, or reused multiple times in a commercial kitchen, that is a defensible position with actual biochemistry behind it.
The grandmother defence turns out to be mostly correct: she used less oil, used cold-pressed or minimally processed fat, cooked at appropriate temperatures, and did not reuse oil until it turned dark. The panic got the villain wrong. The habit it is pointing toward is right.