EPICOR Italian Women: Olive Oil & Leafy Vegetables Linked to 44% Lower CHD Risk

This prospective cohort study from five Italian centers tracked 29,689 women for nearly 8 years to test whether higher intake of fruit, vegetables, and olive oil was associated with lower coronary heart disease incidence. Published in the American Journal of Clinical Nutrition, the EPICOR analysis found that women in the highest quartile of olive oil intake had a 44% lower risk of CHD events, with a similar signal for leafy vegetable consumption. Fruit intake showed no association.

Why This Study Matters

The recommendation to eat more fruit and vegetables is one of the oldest in nutrition. It rests largely on observational evidence linking plant food intake to lower cardiovascular disease risk. But most of that evidence was generated in mixed-sex cohorts where men dominate the CHD event counts, and the analyses rarely separated fruits from vegetables or treated leafy vegetables as distinct from starchy ones. The picture for women specifically was less clear, especially in Mediterranean populations where olive oil consumption complicates the interpretation.

EPICOR was designed to address that gap. It pooled 29,689 women from five Italian EPIC centers spanning northern (Turin, Varese), central (Florence), and southern (Naples, Ragusa) Italy -- a regional spread that captured a wide range of dietary patterns. The study tracked major CHD events (fatal and nonfatal myocardial infarction, and coronary revascularization) over a mean follow-up of 7.85 years.

The findings did three useful things at once: they showed that leafy vegetable intake was independently associated with lower CHD risk, that olive oil intake had a similar magnitude of association, and that the popular advice to "eat more fruit" did not, in this cohort, predict lower CHD risk in women.

How It Was Designed

The basics: 29,689 women, mean follow-up of 7.85 years, five EPIC-Italy centers, recruitment between 1993 and 1998. All participants were free of CHD events at baseline.

Dietary intake was assessed at baseline using validated semi-quantitative food frequency questionnaires adapted for each Italian region, since dietary habits differ substantially between northern and southern Italy. Olive oil intake, leafy vegetable intake, fruit intake, and other dietary variables were calculated and divided into center-specific quartiles to account for regional variation in habitual consumption.

Cox proportional-hazards models were stratified by center and adjusted for hypertension, smoking status, education, menopausal status, physical activity, BMI, waist-to-hip ratio, non-alcohol energy intake, alcohol intake, total meat consumption, vegetable intake (in analyses for fruit), and fruit intake (in analyses for vegetables). The mutual adjustment between fruit and vegetable intake is important -- it lets the researchers separate the effect of one from the other rather than conflating them.

CHD events were ascertained through hospital discharge records, mortality registries, and direct medical record review, then validated by independent committees. Major events were defined as fatal or nonfatal myocardial infarction or coronary revascularization (PCI or CABG).

What They Found

During a mean follow-up of 7.85 years, 144 major CHD events were identified. The multivariable-adjusted hazard ratios for the highest versus lowest quartile of intake were:

Exposure	Hazard Ratio (95% CI)	Risk Reduction	What It Measures
Olive oil (Q4 vs. Q1)	0.56 (0.31-0.99)	44% lower	Major CHD events, p for trend = 0.04
Leafy vegetables (Q4 vs. Q1)	0.54 (0.33-0.90)	46% lower	Major CHD events, p for trend = 0.03
Total fruit (Q4 vs. Q1)	No association	--	No statistically significant relationship

Green indicates a favorable direction vs. lowest quartile. Both olive oil and leafy vegetable findings reached statistical significance with linear p-for-trend values.

Reading the Results

The findings group into three threads.

Olive oil (44% lower CHD risk). The size of the effect is at the upper end of what cohort studies typically report for a single dietary exposure. The mechanism is plausible: olive oil delivers monounsaturated fat that improves the LDL/HDL ratio, plus polyphenols (hydroxytyrosol, oleuropein, oleocanthal) that reduce oxidized LDL and inflammation. The graded p-for-trend (0.04) confirms that the relationship is dose-dependent across quartiles, not just a top-vs-bottom artifact.

Leafy vegetables (46% lower CHD risk). Closely matched to the olive oil effect in magnitude and significance. Leafy greens are concentrated sources of nitrate, folate, magnesium, and polyphenols -- all of which have been linked to favorable cardiovascular biomarkers. The fact that the EPICOR analysis adjusted mutually for fruit and vegetable intake means this is the leafy-vegetable signal independent of overall plant food consumption.

Fruit (no association). This is the result most worth being honest about. Despite a large sample and adequate event count, total fruit intake was not associated with CHD risk in this Italian female cohort. That doesn't mean fruit is unimportant for overall health -- it has clear benefits for other outcomes -- but it does suggest that, at least in this population and for this endpoint, the protective signal from plant foods runs through vegetables (especially leafy ones) and olive oil rather than fruit.

What Didn't Change

Total fruit intake showed no statistically significant association with CHD risk in this cohort. This is consistent with several other European cohort analyses where the fruit signal for CHD is weaker than the vegetable signal -- but it's a finding that runs against the common "5 a day" framing. The researchers don't extend the result beyond what it shows.

The study is observational, not interventional. It cannot prove causation. With 144 events, the analysis has adequate but not large statistical power, which means moderate true effects could remain undetected and the wide confidence intervals on the significant findings should be read accordingly.

Broader Context

EPICOR's olive oil finding sits in the same range as the broader EPIC-Spain analyses (Buckland et al., 2012, BJN and AJCN), which reported 7% and 13% reductions in CHD and cardiovascular mortality per 10 g/day of olive oil intake in mixed-sex Spanish cohorts. The PREDIMED randomized trial showed a 30% reduction in major cardiovascular events with a Mediterranean diet supplemented with extra virgin olive oil. The Harvard pooled cohort (Guasch-Ferre et al., 2022) reported a 19% reduction in cardiovascular mortality in a non-Mediterranean U.S. population.

The 2011 European Food Safety Authority opinion (Regulation 432/2012) authorized a health claim for olive oil polyphenols and protection of blood lipids from oxidative damage at a daily intake of 5 mg of hydroxytyrosol and its derivatives. The EPICOR finding is consistent with that mechanism: the strongest signals came from women whose habitual intake patterns delivered substantial olive oil polyphenols alongside leafy-vegetable nitrate and flavonoids.

What this cohort adds is a women-specific analysis in a Mediterranean population, with the mutual adjustment for fruit and vegetable intake that lets the leafy-vegetable and olive-oil signals be read independently.

Related Research

Continue exploring olive oil and polyphenol science:

• EPIC-Spain: Olive Oil Linked to Lower Coronary Heart Disease Risk
• EPIC-Spain: Higher Olive Oil Intake Linked to 26% Lower Mortality
• Italian Cohort: Olive Oil Linked to Lower Cancer, CV and All-Cause Mortality

Source: View the original study on PubMed

Olivea's Dosage

EPICOR identified the largest CHD risk reduction (44%) in the highest quartile of olive oil intake among Italian women. A single tablespoon of Olivea extra virgin olive oil delivers approximately 14 grams. Each Olivea capsule delivers over 20 mg of hydroxytyrosol per serving in an EVOO matrix; our most recent third-party certificate of analysis confirmed 23.5 mg per capsule.

We share this research for transparency. This is an independent study -- we did not fund it, design it, or conduct it.

Editorial Information

Research note. This article summarizes third-party research published in a peer-reviewed journal. Olivea did not conduct or fund the study. Findings reflect the cited paper only and do not establish efficacy of Olivea products.

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