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Olive Oil Research LibrarySalute & Benessere

Reading the
research.La scienza
in ogni goccia.

A guide to selected peer-reviewed studies about extra virgin olive oil, its compounds and Mediterranean dietary patterns — what researchers investigated, what they found and what the studies do not prove.

Research information, not a product health claim or medical advice. UK rules do not permit a food to claim that it prevents, treats or cures disease. The studies summarised here concern particular populations, diets, compounds and experimental conditions; they do not establish that Castruriali will produce the same outcome for an individual. Never change medication or treatment because of this page. Speak to a qualified healthcare professional about your circumstances.
In brief

Researchers have studied extra virgin olive oil within Mediterranean dietary patterns and have separately investigated compounds including hydroxytyrosol and oleocanthal. This page reports selected findings with their sources and limitations. It does not turn those findings into promises about Castruriali. Our 2024/2025 early-harvest oil was independently measured at 410 mg/kg total polyphenols; that compositional result alone does not prove a health effect or establish eligibility for any particular authorised claim.

73%
Approximate oleic-acid proportion often reported for olive oil; composition varies
Keys, Seven Countries Study
30%
Approximate relative difference in PREDIMED’s composite outcome for one dietary intervention
PREDIMED, NEJM 2013
30+
Distinct phenolic antioxidants identified in extra virgin olive oil
Peer-reviewed analyses
— Head to Toe

What studies investigate.

Select a research area for a plain-English summary. Association, laboratory mechanism and clinical outcome are different kinds of evidence; each panel identifies that context.

HeartBrainGutJointsSkin
Cardiovascular research

What researchers study about the heart.

PREDIMED compared Mediterranean dietary patterns, including one supplemented with extra virgin olive oil, with a control diet in people at cardiovascular risk. It studied a whole dietary intervention, not Castruriali and not olive oil as a treatment.

~30%
relative difference reported for the composite primary outcome in the EVOO intervention group
Diet
the intervention involved an overall Mediterranean eating pattern
Estruch R. et al. — New England Journal of Medicine 2018;378:e34. Read the study design, population, endpoints and corrected republication.
— What's Inside

The active compounds.

Open a topic to see what researchers examine and the limits on applying those findings to a food product or an individual.

Monounsaturated fats

Oleic acid is the principal fatty acid in olive oil.

Research topics
  • Dietary-fat substitution
  • Blood-lipid markers
  • Mediterranean dietary patterns
Evidence
Population and dietary-intervention research has examined oleic acid as part of Mediterranean eating patterns; outcomes cannot be attributed to one food alone.
The Castruriali difference
This is background research about olive oil generally, not a promise about an individual health outcome.

Olive-oil polyphenols

A family of minor compounds studied in EVOO.

Research topics
  • Oxidative processes
  • Blood-lipid oxidation
  • Processing and storage
Evidence
EFSA assessed evidence concerning olive-oil polyphenols and protection of blood lipids from oxidative stress. Any commercial use of the authorised wording is subject to exact composition and consumption conditions.
The Castruriali difference
Our laboratory reports total polyphenols; that result is not presented here as proof of a medical effect.

Oleocanthal

A phenolic compound associated with a peppery sensation.

Research topics
  • Laboratory enzyme activity
  • Sensory chemistry
  • Questions for further human research
Evidence
Beauchamp et al. reported ibuprofen-like COX-enzyme activity in laboratory research. That finding does not mean olive oil is ibuprofen or can treat pain or inflammation.
The Castruriali difference
A peppery finish is a sensory characteristic, not a medicinal claim.

Vitamin E

A fat-soluble nutrient found in varying amounts in oils.

Research topics
  • Food composition
  • Oxidative-stress research
  • Effects of processing
Evidence
Nutrition research examines vitamin E and oxidative processes. Whether a particular nutrition claim may be used depends on verified nutrient levels and the legal conditions for that claim.
The Castruriali difference
No vitamin E claim is made for Castruriali on this page.

Squalene

A naturally occurring component studied in olive oil.

Research topics
  • Food chemistry
  • Cell and laboratory studies
  • Variation by cultivar and processing
Evidence
Published work discusses squalene in experimental contexts. Laboratory findings are not evidence that eating a particular oil will treat or prevent a condition.
The Castruriali difference
Content varies between oils and harvests; this page does not quantify Castruriali squalene.

Phytosterols

Plant sterols occur naturally in plant foods.

Research topics
  • Food composition
  • Cholesterol-absorption research
  • Dose-dependent effects
Evidence
Controlled studies have investigated plant sterols at defined doses. Their findings should not be transferred automatically to an ordinary serving of olive oil.
The Castruriali difference
No plant-sterol health claim is made for Castruriali.

Carotenoids

Pigments investigated in food-composition research.

Research topics
  • Colour and composition
  • Oxidation during storage
  • Variation between harvests
Evidence
Carotenoids are widely studied nutrients, but colour alone cannot establish their amount or a health effect.
The Castruriali difference
The colour of an oil is not a measure of quality or medical benefit.

Chlorophyll

A pigment that contributes to the colour of some oils.

Research topics
  • Food chemistry
  • Light sensitivity
  • Changes during storage
Evidence
Research considers chlorophyll both as a pigment and in oxidation chemistry. Broad “detox” claims are not supported or made here.
The Castruriali difference
Store olive oil away from heat and light to protect quality.

Phenolics and the microbiome

An emerging area of nutrition research.

Research topics
  • Microbiome composition
  • Metabolites
  • Limits of early-stage evidence
Evidence
Small and experimental studies explore interactions between dietary phenolics and gut microbes. This evidence does not establish that an olive oil treats digestive problems.
The Castruriali difference
The research is developing and should be read with appropriate caution.
— In the Kitchen

Enjoying the oil.

Practical serving and storage ideas for flavour and food quality, not a prescribed dose or treatment plan.

Taste It Neat

A small taste can help you notice fruitiness, bitterness and the peppery finish — sensory qualities, not a medical test.

Finish, Don't Fry

Drizzle raw over finished dishes to keep the most delicate antioxidants intact.

Fresh Is Best

Use opened bottles within a few months — polyphenols fade gently with time.

Pair With Plants

Use it as part of meals with vegetables, grains, pulses, fish or bread according to your taste and dietary needs.

  1. Keys, A. (1970) 'The Seven Countries Study', Nutrition Today, 5(2).
  2. Estruch, R. et al. / PREDIMED Investigators (2018), 'Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts', New England Journal of Medicine.
  3. Beauchamp, G.K. et al. (2005), 'Phytochemical ibuprofen found in extra-virgin olive oil', Nature, 437, pp. 45–46.
  4. Valls-Pedret, C. et al. (2015), 'Mediterranean Diet and Age-Related Cognitive Decline', JAMA Internal Medicine.
  5. Cerdá, B. et al. (2016) 'Gut microbiota modification with polyphenols', Frontiers in Microbiology, 7, 923.
  6. Traber, M.G. & Atkinson, J. (2007) 'Vitamin E, antioxidant and nothing more', Annual Review of Nutrition, 27.
  7. Ostlund, R.E. (2002) 'Phytosterols and cholesterol metabolism', The American Journal of Cardiology, 90(5).
  8. Smith, T.J. et al. (2000) 'Squalene and its potential chemopreventive properties', Nutrition and Cancer, 38(1).
  9. Tsukahara, K. et al. (2001) 'Olive oil and skin', Dermatology.
  10. European Food Safety Authority (2011), 'Scientific Opinion on the substantiation of health claims related to polyphenols in olive', EFSA Journal, 9(4):2033.
  11. Schwingshackl, L. & Hoffmann, G. (2014) 'Monounsaturated fatty acids, olive oil and health status', Lipids in Health and Disease, 13:154.
  12. Guasch-Ferré, M. et al. (2022), 'Consumption of Olive Oil and Risk of Total and Cause-Specific Mortality Among U.S. Adults', Journal of the American College of Cardiology, 79(2):101–112.
  13. World Health Organization, Healthy diet fact sheet.
  14. Martínez-González, M.A. et al. (2019), 'The Mediterranean Diet and Cardiovascular Health', Circulation Research, 124(5):779–798.
What UK food law allows us to say

Replacing saturated fats with unsaturated fats in the diet contributes to the maintenance of normal blood cholesterol levels. Oleic acid is an unsaturated fat.

About 92% of the fat in Castruriali is unsaturated (7.6 g saturated fat per 100 g; independent lab report, December 2024). Enjoy as part of a varied and balanced diet and a healthy lifestyle. This is the authorised health claim Castruriali meets. Everything else on this page describes published research about olive oil and diet in general.

Important: this commercial website sells extra virgin olive oil. This page is a selective educational summary, not a systematic review, diagnosis, treatment recommendation or medical advice. Extra virgin olive oil is a food, not a medicine and must not be used in place of prescribed treatment. UK food advertising rules prohibit claims that a food prevents, treats or cures disease; no such claim is intended. Consult a doctor, registered dietitian or other qualified healthcare professional for advice about a condition, medication, allergy or dietary requirement.

Written by the Castruriali Editorial Team. Castruriali sells extra virgin olive oil and has a commercial interest in this subject.

Deeper reading
PREDIMED republication →EFSA scientific opinion →GB nutrition and health claims register →Editorial policy →
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Castruriali’s 2024/2025 Early harvest was independently tested at 410mg/kg total polyphenols. Cold extracted below 27°C and awarded Great Taste 2025.Olio extravergine da olive coltivate sulle colline di Salemi, in provincia di Trapani, prodotto e imbottigliato a mano a Castroreale. Raccolta precoce 2024/2025: Great Taste 2025, 410 mg/kg di polifenoli, analizzati da un laboratorio indipendente.

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