The healthiest challenge begins: olive oil takes the podium

IN BRIEF

• Regular use of olive oil, especially extra-virgin, is associated with a lower risk of cardiovascular events in observational studies and favorable outcomes in clinical trials based on the Mediterranean model.
• The nutritional profile of olive oil (monounsaturated fats and polyphenols) explains plausible protective mechanisms: lipid modulation, reduction of inflammation, and antioxidant actions.
• Coconut oil increases LDL cholesterol compared to non-tropical vegetable oils; clinical literature does not support clear metabolic advantages over oils rich in unsaturated fats.
• Evidence includes observational studies, randomized clinical trials, and meta-analyses; each source has methodological limitations that require cautious interpretation before drawing causal conclusions.

Abstract: what does science say?

Olive oil, particularly extra-virgin, combines a high proportion of monounsaturated fatty acids with active phenolic compounds. Epidemiological evidence from large cohorts suggests inverse associations between olive oil consumption and the risk of cardiovascular diseases and mortality; the most robust results come from observational studies and trials on the Mediterranean diet model that include a consistent intake of EVOO. Experimental studies identify plausible mechanisms (lipid modulation, anti-inflammatory effects, endothelial protection, and neuroprotective actions of polyphenols like hydroxytyrosol). However, the magnitude of the effects depends on dose, oil quality, overall dietary habits, and study design; therefore, associations should not be automatically translated into causal relationships without considering limitations and context.

Composition and biological mechanisms

Olive oil is characterized by a prevalence of oleic acid (a monounsaturated fat) and a smaller but biologically relevant fraction of phenolic compounds: hydroxytyrosol, oleuropein, oleocanthal, and others. These molecules have antioxidant properties and modulate inflammatory and oxidative stress signals, with observed effects on blood markers and endothelial function. Meta-analyses and reviews of clinical trials show that interventions with olive oil can reduce indicators of inflammation and improve parameters of endothelial dilation, suggesting a favorable vascular effect [6].

From a metabolic perspective, replacing saturated fats with monounsaturated fats can affect plasma lipid levels and lipoprotein composition; furthermore, olive oil phenols can modulate intracellular processes related to stress response (e.g., antioxidant pathways and NF-κB signaling). Experimental studies indicate that specific polyphenols, such as hydroxytyrosol, improve mitochondrial functions and show neuroprotective activity in preclinical models [7][8]. These mechanisms provide biological plausibility for epidemiological associations but do not alone demonstrate a causal relationship without adequate clinical data.

Epidemiological and clinical evidence

Available evidence includes large observational studies, preclinical experiments, and randomized clinical trials. In two large U.S. cohorts, even a modest increase in olive oil consumption was associated with a reduced risk of cardiovascular diseases and coronary heart disease; replacing other fat sources (margarine, butter, mayonnaise) with olive oil was associated with a lower risk of cardiovascular events [1].

The large PREDIMED trial provided experimental data supporting the protective role of the Mediterranean diet enriched with extra-virgin olive oil: in participants at high cardiovascular risk, the Mediterranean diet with integrated EVOO was associated with a reduction in major cardiovascular events compared to a control diet [3]. Subsequent analyses of the same program highlighted dose-dependent reductions in risk linked to increased olive oil intake [4].

Reviews and meta-analyses of observational and interventional studies suggest an overall favorable association between olive oil consumption and the risk of stroke and other cardiovascular events, albeit with heterogeneity among studies and potential confounding factors to consider [5]. These sources justify a general recommendation for unsaturated vegetable oils over saturated fats, while maintaining a cautious interpretation of the data.

Comparison with coconut oil and other fats

In recent years, coconut oil has been at the center of popular debate. Reviews of clinical trials show that coconut oil, compared to non-tropical vegetable oils, tends to increase LDL cholesterol (the so-called "bad cholesterol"), although often also raising HDL: such a lipid profile is not clearly advantageous for the prevention of cardiovascular diseases and concerns researchers [2].

Many studies compare the effect of replacing saturated fats (butter) with oils rich in unsaturated fats (olive oil, rapeseed, sunflower): replacement with olive oil is generally associated with reductions in cardiovascular risk factors. The difference between non-tropical vegetable oils and coconut oil is particularly important when the goal is LDL reduction; the mere presence of increased HDL does not automatically compensate for the possible worsening of the overall atherogenic profile.

What it means in practice

For the general public: the results indicate that preferring vegetable oils rich in mono- and polyunsaturated fats — with extra-virgin olive oil at the forefront — instead of fats rich in saturated fats (butter, some lard derivatives, and to a limited extent margarines rich in saturated fatty acids) is a strategy consistent with reducing cardiovascular risk factors. Even small daily substitutions (e.g., a teaspoon a day) have been associated with differences in risks in observational studies [1].

The quality of the oil matters: extra-virgin oils contain more polyphenols than refined oils and, when used raw or at low temperatures, better preserve bioactive components. In the context of an overall balanced diet (rich in vegetables, legumes, whole grains, and lean proteins), olive oil can help improve the nutritional profile without miraculous therapeutic promises.

Choice and use in cooking

Choosing a good quality extra-virgin olive oil for raw dressings or light cooking is a reasonable option. For prolonged frying, it is appropriate to consider the smoke point and thermal stability: olive oil has good resistance compared to other monounsaturated oils, but repeated high-temperature cooking can degrade sensitive compounds. Storing oil away from light and heat reduces oxidation and maintains the phenolic fraction longer.

Oil variants and quality

Not all olive oils are equivalent: "extra-virgin" indicates production without chemical processes and a limited content of sensory defects, while the label "virgin" or "refined" indicates different levels of quality and polyphenol concentration. The presence of high polyphenols is associated with greater potential biological benefits; however, certification and origin are useful elements of transparency for the consumer.

KEY POINTS TO REMEMBER

• Olive oil, especially extra-virgin, is associated with a reduced cardiovascular risk in observational evidence and supported by trials based on the Mediterranean model.
• Phenolic compounds (e.g., hydroxytyrosol) provide biological plausibility for antioxidant, anti-inflammatory, and neuroprotective effects.
• Coconut oil tends to increase LDL compared to non-tropical vegetable oils and is not recommended as a first choice for cardiovascular health.
• Oil quality (extra-virgin vs. refined), dose, and dietary context influence health impact.

Limitations of the evidence

It is crucial to distinguish between observational associations and demonstrated causal relationships. Observational studies on large cohorts can be influenced by lifestyle and socioeconomic factors that correlate with oil choice; even when correcting for many variables, the risk of residual confounding remains [1].

Randomized clinical trials evaluating dietary patterns (e.g., PREDIMED) provide more robust evidence, but often combine multiple dietary components (not just olive oil), making it difficult to isolate the effect of a single substance [3]. Meta-analyses and reviews can synthesize data but suffer from methodological heterogeneity among studies, differences in duration, dose, and studied populations [5][6].

Finally, many preclinical studies on polyphenols show promising mechanisms, but direct translation into clinical benefits in humans requires caution: doses, bioavailability, and interactions with diet vary considerably between experimental models and human use [8].

Editorial conclusion

In light of the available evidence, olive oil, and particularly extra-virgin, represents a dietary choice consistent with cardiovascular prevention when it replaces fats rich in saturated fats. The evidence combines large-scale observational data, plausible experimental results, and trials that include the Mediterranean model. However, a cautious approach is necessary: the choice of oil is one component of an overall diet and not an isolated remedy. For personal decisions in the presence of specific pathologies, it is advisable to consult a doctor or a healthcare professional.

Editorial note

This article was originally published in the past and updated based on criteria of scientific evidence and clear communication. The purpose is informative: it does not replace individual medical advice. The information presented here refers to selected studies and literature reviews; complete references are provided in the "Scientific Research" section to allow for verification and further study.

SCIENTIFIC RESEARCH

1. Guasch‑Ferré M, Liu G, Li Y, Sampson L, Manson JE, Salas‑Salvadó J, Martínez‑González MA, Stampfer MJ, Willett WC, Sun Q, Hu FB. Olive oil consumption and cardiovascular risk in U.S. adults. J Am Coll Cardiol. 2020;75(15):1729–1739. https://doi.org/10.1016/j.jacc.2020.02.036
2. "The Effect of Coconut Oil Consumption on Cardiovascular Risk Factors: A Systematic Review and Meta‑Analysis of Clinical Trials." Circulation. 2020. https://doi.org/10.1161/CIRCULATIONAHA.119.043052
3. Estruch R, Ros E, Salas‑Salvadó J, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med. 2013;368:1279–1290. https://doi.org/10.1056/NEJMoa1200303
4. Guasch‑Ferré M, Corella D, Estruch R, et al. Olive oil intake and risk of cardiovascular disease and mortality in the PREDIMED Study. BMC Med. 2014;12:78. https://doi.org/10.1186/1741-7015-12-78
5. Meta‑analysis: Olive oil consumption and risk of CHD and/or stroke: a meta‑analysis of case‑control, cohort and intervention studies. Br J Nutr. 2014;112:248–259. https://doi.org/10.1017/S0007114514000713
6. Schwingshackl L, Christoph M, Hoffmann G. Effects of olive oil on markers of inflammation and endothelial function — a systematic review and meta‑analysis. Nutrients. 2015;7:7651–7675. https://doi.org/10.3390/nu7095356
7. Meta‑analysis: Olive oil polyphenols improve HDL cholesterol and promote maintenance of lipid metabolism: systematic review and meta‑analysis (Metabolites 2023). https://doi.org/10.3390/metabo13121187
8. D’Andrea G, Ceccarelli M, Bernini R, Clemente M, Santi L, Caruso C, Micheli L, Tirone F. Hydroxytyrosol stimulates neurogenesis in aged dentate gyrus by enhancing stem and progenitor cell proliferation and neuron survival. FASEB J. 2020;34:4512–4526. https://doi.org/10.1096/fj.201902643R