If you spend ten minutes searching online, you will probably run into a confusing fact: mustard oil is "banned for cooking" in the United States. The bottle on the shelf there often says "for external use only." Meanwhile in India — the world's largest producer and consumer of mustard oil — it has been the everyday cooking medium of crores of households for centuries.
So which is right? Is your dadi's beloved sarson ka tel actually bad for your heart? Or is the American warning overblown? The honest answer involves a fatty acid called erucic acid, some animal studies from the 1970s, and a much more recent understanding of how mustard oil affects human cholesterol. Here is the full story.
The erucic acid story, in plain English
Mustard oil naturally contains erucic acid — a long-chain monounsaturated fatty acid that makes up roughly 20% to 40% of the oil. In the 1970s, researchers fed very high doses of erucic acid to rats and observed fatty deposits forming in the rats' heart muscle. That single set of findings shaped global food policy.
Based on those animal studies, the U.S. FDA issued Import Alert 26-04, restricting mustard oil for use as a cooking oil. The EU, Australia and New Zealand chose a different path — they set upper limits for erucic acid in food rather than banning the oil outright.
What the FDA actually said — and what they didn't
This is the part most articles skip. The FDA's restriction was a precautionary measure based on rat studies, not on evidence of human heart damage. To this day, no large human study has shown that the erucic acid in mustard oil causes the kind of fatty heart deposits seen in those original rat experiments.
Walter Willett, the long-time chair of the Nutrition Department at the Harvard School of Public Health, has gone on record saying the erucic acid levels in mustard oil are not necessarily dangerous — though more human research would be welcome. A 2021 review in the Journal of Clinical Lipidology, titled "Mustard oil and cardiovascular health: Why the controversy?", concluded that the cardiovascular case against mustard oil is much weaker than the FDA's blanket warning suggests.
What Indian research has been finding
While the Western conversation got stuck on rat studies, Indian researchers were doing something useful: studying mustard oil in actual human populations.
Findings consistently show that mustard oil, especially in its traditional cold-pressed (kachi ghani) form, has a fatty-acid profile that looks good for the heart:
- Around 60% monounsaturated fat (MUFA) — the same kind of "good fat" that makes olive oil famous.
- Roughly 21% polyunsaturated fat (PUFA), including a useful dose of plant-based omega-3 (alpha-linolenic acid) — rare in cooking oils.
- Only about 12% saturated fat, lower than ghee, butter, or coconut oil.
Studies on Indian populations have linked traditional mustard-oil cooking with lower LDL ("bad") cholesterol, higher HDL ("good") cholesterol, and a reduced risk of ischemic heart disease compared to refined vegetable oils. One often-cited Indian cohort study found that people who used mustard oil at home had a 71% lower risk of coronary heart disease compared to those using sunflower oil.
Why "kachi ghani" matters, not just "mustard"
This is where a lot of brands quietly let the consumer down. Mustard oil sold as "refined mustard oil" is treated with high heat, hexane solvents, bleaching agents, and deodorisers. The chemical refining process removes erucic acid — but it also destroys the omega-3 fatty acids, the natural antioxidants, and the pungent flavour that made mustard oil valuable in the first place.
Kachi ghani, on the other hand, means the oil is extracted by slowly pressing the mustard seeds in a wooden or low-temperature mechanical press — no heat above the natural friction of crushing, no chemical solvents, no bleaching. What you pour into the kadai is essentially what is inside the seed.
That is why traditional doctors and modern nutritionists end up agreeing on the same recommendation: if you are going to use mustard oil, use the kachi ghani kind.
How to use mustard oil safely in your kitchen
Generations of Indian cooks have already worked out the right techniques. The science just confirms what they figured out:
- Heat it once, until it just starts smoking — then lower the flame. This traditional step ("smoke the oil") reduces the raw pungency and any harsh notes. Don't keep it at smoking heat.
- Use a stable smoke point. Kachi ghani mustard oil has a smoke point of around 250°C, comfortably above normal sautéing, frying, and tadka temperatures.
- Don't reuse fried oil multiple times. This rule applies to every cooking oil — repeatedly heated oils produce harmful compounds regardless of source.
- Stay within sensible amounts. Indian dietary guidelines suggest 20–30 ml of total cooking oil per person per day. Mustard oil at this quantity has never been linked to heart problems in human studies.
What about erucic acid in modern mustard varieties
Mustard breeders have spent decades reducing erucic acid in many cultivars. But the traditional Indian black mustard (kali sarson) still carries the full flavour, full aroma, and the higher monounsaturated profile that the science is now defending. The choice between flavour-rich traditional oil and modern low-erucic varieties is a personal one — but the case for fearing kali sarson is much weaker than the old warnings suggest.
How to know your bottle is actually pure
Here is the catch: most of the heart-health benefits of mustard oil only show up if the oil in your bottle is actually unrefined, unblended, and free of cheap fillers like palm or rice bran oil. Adulteration is a real problem in the Indian mustard oil market.
The simplest protection is independent lab testing. At Chahal Agri Farms, our Kachi Ghani Black Mustard Oil is wood-pressed from traditional kali sarson grown in West Uttar Pradesh, with no chemical refining, no heat treatment beyond natural pressing friction, and no blending. Every batch goes to Equinox Labs in Navi Mumbai — a NABL-accredited laboratory — so you can verify what you are pouring into your pan.
The takeaway
The "mustard oil is bad for your heart" headline is built on 50-year-old rat studies and a precautionary American import rule. The actual human research, much of it done in India where mustard oil is the daily cooking medium, points in the opposite direction — modest amounts of kachi ghani mustard oil are associated with better cholesterol numbers and a lower risk of heart disease compared to refined seed oils.
The conditions are simple: choose unrefined, cold-pressed (kachi ghani) oil, use it in normal cooking quantities, don't reuse heavily fried oil, and buy from a source that can prove its purity through lab testing.
If you would like to taste the difference for yourself, our Kachi Ghani Black Mustard Oil is available at chahalagrifarms.com — traditionally pressed, NABL lab tested, and bottled the same way our family has been making it for generations.
