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Olive Oil

Table of Contents

Olive oil composition and quality grades
Polyphenols and bioactive compounds
Cardiovascular and metabolic health
Culinary considerations and storage

Olive oil composition and quality grades

Olive oil is a fat extracted from the fruit of the olive tree, primarily through mechanical pressing. Extra virgin olive oil (EVOO) represents the highest quality classification and is produced through cold pressing without chemical extraction or refinement. Unlike refined oils, EVOO retains its natural antioxidant compounds, polyphenols, and flavor compounds, making it significantly more nutritious than other olive oil categories. The primary fatty acid in olive oil is oleic acid, a monounsaturated fat that comprises approximately 70% of the oil. This healthy fat profile contributes to olive oil's anti-inflammatory and cardiovascular benefits ^[3].

Polyphenols and bioactive compounds

Extra virgin olive oil contains numerous polyphenolic compounds including secoiridoids, oleuropein, and hydroxytyrosol, which possess powerful antioxidant and anti-inflammatory properties ^[2]. These compounds help neutralize free radicals and reduce oxidative stress in the body. Research has demonstrated that high-polyphenol olive oils can reduce markers of inflammation including C-reactive protein and IL-6, even in low quantities. The peppery sensation in the throat when tasting olive oil is actually indicative of the polyphenol content.

Cardiovascular and metabolic health

The PREDIMED study demonstrated that a Mediterranean diet supplemented with extra virgin olive oil reduced cardiovascular events by 30% compared to a standard low-fat diet ^[1]. A large observational study confirmed that regular olive oil consumption is associated with lower cardiovascular mortality ^[4]. The oleic acid in olive oil helps reduce LDL oxidation, a key step in atherosclerosis development. Additionally, olive oil consumption is associated with improved insulin sensitivity and better glycemic control.

Culinary considerations and storage

While extra virgin olive oil is exceptionally healthy, its use should be contextual. The smoke point of EVOO (190-210°C) is lower than refined oils, making it less suitable for high-heat frying, though it works well for sauteing and baking. Light, heat, and oxygen degrade olive oil quality rapidly. Store olive oil in a cool, dark place in dark glass bottles or tins to preserve polyphenol content. For maximum health benefits, consume 2-3 tablespoons daily, ideally raw in salads or as a finishing oil ^[5].

References

Choose early-harvest oils for more polyphenols

Oils pressed from olives harvested early in the season contain up to 3x more polyphenols than late-harvest oils. Look for harvest dates on the bottle and choose oils pressed within 6 months.

pubmed.ncbi.nlm.nih.gov

Store olive oil away from light and heat

Light and heat destroy polyphenols rapidly. Keep your olive oil in a cool, dark cupboard in dark glass or tin containers. Avoid clear bottles stored near the stove or windows.

Use EVOO for low to medium heat cooking

Contrary to popular belief, extra virgin olive oil is stable for sautéing and baking up to 190°C. Save your premium oils for raw use in dressings and drizzles, but don't be afraid to cook with regular EVOO.

Aim for 2-3 tablespoons daily

The PREDIMED study found cardiovascular benefits with approximately 4 tablespoons of EVOO daily. Start with 2-3 tablespoons in salads, cooking, and as a finishing oil to reap the polyphenol benefits.

www.nejm.org

Taste for quality before buying

Quality EVOO should smell fresh and fruity with a peppery kick in the throat that indicates high polyphenol content. Avoid oils that smell like crayons, stale nuts, or have no aroma at all.

What is the difference between extra virgin and regular olive oil?

Extra virgin olive oil is the highest grade, produced by cold mechanical pressing without chemicals or heat. It retains natural polyphenols and has acidity below 0.8%. Regular olive oil is typically a blend of refined and virgin oils, processed with heat and chemicals, resulting in fewer health compounds and a neutral flavor.

Can you cook with extra virgin olive oil or should it only be used raw?

You can absolutely cook with extra virgin olive oil. Its smoke point (190-210°C) is suitable for sautéing, roasting, and most home cooking. While very high-heat frying might degrade some delicate polyphenols, the oil remains stable and healthy. Reserve your finest EVOO for drizzling raw on salads and finished dishes.

What are polyphenols and why do they matter in olive oil?

Polyphenols are plant compounds with powerful antioxidant and anti-inflammatory properties. In olive oil, they help reduce oxidative stress, lower inflammation markers like C-reactive protein, protect LDL cholesterol from oxidation, and improve endothelial function. High-polyphenol olive oils provide greater cardiovascular benefits than low-polyphenol varieties.

How long does olive oil last and how should it be stored?

Unopened olive oil typically lasts 18-24 months from harvest when stored properly. Once opened, use within 2-3 months for optimal quality. Store in a cool, dark place in dark glass or tin containers. Light, heat, and oxygen are the main enemies of olive oil quality, causing oxidation and rancidity. Never store olive oil in clear bottles on countertops or near stoves.