Vegetable Oil vs Olive Oil: Which Is Actually Better?

Both come in a bottle. Both are liquid at room temperature. Both are marketed as cooking oils. Beyond these superficial similarities, vegetable oil and extra virgin olive oil are about as different as two cooking fats can be — in origin, processing, fatty acid composition, and their effects on your body.

What Is "Vegetable Oil"?

The term "vegetable oil" is deliberately vague. It is a commercial label covering any blend of refined oils extracted from plant sources. In practice, in the United States, "vegetable oil" typically means soybean oil, often blended with canola. In the United Kingdom, it typically means a blend of rapeseed and soybean oil.

The vagueness serves a commercial purpose: it allows manufacturers to substitute between oil types based on price, without changing the label. What consumers see as a consistent product is actually a variable blend, optimised for cost.

What unites these oils is their manufacturing process:

1. Seeds are crushed and oil extracted using hexane solvent
2. The crude oil is then bleached to remove colour
3. It is then deodorised using heat treatment (up to 270°C with steam) to remove the naturally unpleasant smell of solvent-extracted seed oil
4. Antioxidants (BHA, BHT) are added back to extend shelf life

This process strips the oil of most naturally occurring vitamins, antioxidants, and flavour compounds. The result is a clear, flavourless, shelf-stable product.

What Is Olive Oil?

Olive oil is extracted from the fruit flesh of olives — making it technically a fruit oil rather than a seed oil. Extra virgin olive oil (EVOO) is produced by cold-pressing whole olives with no heat or chemical treatment. The result retains the fatty acids, polyphenols, tocopherols, and other bioactive compounds naturally present in the olive.

This is a fundamentally different production process that produces a fundamentally different product.

Omega-6 Content Comparison

This is the starkest difference between the two:

| Oil | Omega-6 (LA) per tablespoon | Omega-3 per tablespoon | |-----|----------------------------|------------------------| | Sunflower oil | 8.9g | trace | | Corn oil | 7.3g | trace | | Soybean (vegetable) oil | 7.0g | 0.9g | | Extra virgin olive oil | 0.8g | 0.1g |

At two tablespoons of cooking oil per day:

• Vegetable oil: 14–18g omega-6 daily from oil alone
• Extra virgin olive oil: 1.6g omega-6 daily from oil alone

That is a difference of 12–16g of omega-6 per day — approximately equal to 3–4 standard fish oil capsules' worth of EPA/DHA that would be needed just to compensate for the additional omega-6 in the ratio denominator.

Beyond Omega-6: The Polyphenol Advantage

Extra virgin olive oil offers a second major advantage: polyphenol content. These are plant compounds with biological activity independent of the fatty acid profile.

Oleocanthal

A phenolic compound found in EVOO that inhibits COX-1 and COX-2 enzymes — the same enzymes targeted by ibuprofen and aspirin. Research by Beauchamp et al. (2005) published in Nature found that 50g of EVOO (approximately 3.5 tablespoons) has COX-inhibitory activity equivalent to approximately 10% of an adult dose of ibuprofen.

The sharp, peppery sensation at the back of the throat when tasting high-quality EVOO is caused by oleocanthal — a useful quality indicator.

Hydroxytyrosol and Oleuropein

These polyphenols have antioxidant properties, reduce LDL oxidation, and have demonstrated anti-inflammatory effects in cell and animal studies. They are also associated with improved endothelial function (the cells lining blood vessels).

Refined olive oil (as distinct from EVOO) contains minimal polyphenols — they are largely removed during the refining process. This distinction matters when buying "olive oil" vs "extra virgin olive oil."

Smoke Points and Cooking Stability

A common objection to using EVOO for cooking is the claim that its lower smoke point makes it unstable. This deserves examination.

Smoke point of EVOO: 190–207°C (varies with polyphenol content and acidity level; higher quality EVOO has a higher smoke point)

Typical home cooking temperatures:

• Gentle sautéing: 120–160°C
• Medium sauté/stir fry: 160–180°C
• Roasting at 180°C: surface temperature similar to pan temperature
• Deep frying: 175–185°C

For most everyday home cooking, EVOO's smoke point is adequate. The main exception is high-heat searing (reaching 220°C+) and deep frying at high temperatures — for which avocado oil or ghee are better choices.

Furthermore, smoke point is not the only stability metric. The oxidative stability of an oil — its resistance to producing harmful oxidation products like aldehydes and peroxides — depends more on saturated and monounsaturated fat content than on smoke point. Research from Martin Grootveld's group at De Montfort University found that sunflower oil produced 20× more toxic aldehydes when heated to 180°C for 20 minutes than EVOO — despite sunflower oil having a higher smoke point.

Processing Differences: What You're Actually Consuming

The difference in processing between vegetable oil and EVOO cannot be overstated:

Extra virgin olive oil: Olives picked → crushed → oil separated by centrifuge (cold press). No heat above ambient. No chemicals. No stripping of nutrients. The oil you buy is essentially what was in the olive.

Vegetable/soybean oil: Seeds harvested → flaked and heated → hexane solvent extraction → miscella (oil/hexane mixture) → hexane removal via heat → degumming → neutralisation → bleaching → steam deodorisation at high temperature → antioxidant addition. What you buy bears little resemblance to the raw seed.

Cost Comparison

Extra virgin olive oil typically costs 2–4× more per litre than vegetable oil. At two tablespoons daily, the difference in weekly cost between the cheapest vegetable oil and a decent EVOO is approximately £1.50–£2.50 per week in the UK — less than a single coffee.

Against the potential long-term health costs of a chronically imbalanced omega ratio, this cost differential is negligible.

The Verdict

There is no cooking category where vegetable or soybean oil outperforms extra virgin olive oil from a health perspective. EVOO has dramatically lower omega-6, independent anti-inflammatory polyphenols, comparable smoke point for everyday cooking, and better oxidative stability when heated.

The only practical reasons to use vegetable oil over EVOO are cost (modest difference per serving) and, occasionally, neutral flavour requirements in baking (where refined avocado oil is a better neutral-flavour alternative anyway).

For everyday cooking, switch to extra virgin olive oil. For high-heat applications, switch to avocado oil or ghee. There is no valid health case for continued use of vegetable or sunflower oil in the kitchen.