Dr. Kumar’s Take:
The CORDIOPREV study is one of the most comprehensive long-term studies examining whether a Mediterranean diet rich in extra-virgin olive oil or a low-fat diet is better at preventing heart disease recurrence. After 7 years of follow-up, the results were clear: the Mediterranean diet significantly reduced cardiovascular events compared to the low-fat diet.
For patients with coronary heart disease (CHD), these findings are game-changing. They suggest that switching to a Mediterranean diet could reduce the risk of future heart attacks, strokes, and other cardiovascular events—without strict fat restrictions.
Actionable Tip: If you have heart disease or are at risk, consider following a Mediterranean diet with extra-virgin olive oil. Focus on whole foods, plenty of vegetables, healthy fats, and moderate protein while avoiding processed and low-fat alternatives.
Brief Summary:
The CORDIOPREV study followed 1,002 patients with established coronary heart disease (CHD) for 7 years. Participants were randomized into two dietary groups:
- Mediterranean Diet Group: High in extra-virgin olive oil, fruits, vegetables, whole grains, fish, and nuts (35% fat, mostly from monounsaturated fats like olive oil).
- Low-Fat Diet Group: Based on American Heart Association recommendations, with <30% fat and a higher intake of carbohydrates (>55%).
Key Findings:
✔ Mediterranean diet group had 22% fewer cardiovascular events compared to the low-fat group.
✔ Absolute risk reduction (ARR): 4.9% (17.3% in Mediterranean diet vs. 22.2% in low-fat diet).
✔ Relative risk reduction (RRR): ~22%.
✔ Number needed to treat (NNT): ~20 (meaning for every 20 people who switch to the Mediterranean diet, one major heart event is prevented over 7 years).
✔ Better blood sugar control, lipid profile, and anti-inflammatory effects were observed in the Mediterranean diet group.
Study Design:
This was a randomized, single-blind, controlled trial conducted at the Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC) in Spain. The trial included patients aged 20 to 75 years with documented coronary heart disease, excluding those with severe illnesses.
Results:
✔ The Mediterranean diet group had 87 cardiovascular events (17.3%) vs. 111 in the low-fat group (22.2%).
✔ Lower rates of myocardial infarction, stroke, and cardiovascular deaths in the Mediterranean diet group.
✔ Improved endothelial function and lower inflammation markers with the Mediterranean diet.
✔ No significant difference in weight loss between groups.
Understanding the Numbers:
- Absolute risk reduction (ARR) = 4.9% → This means that for every 100 people following the Mediterranean diet instead of a low-fat diet, about 5 heart-related events were prevented.
- Relative risk reduction (RRR) = ~22% → This indicates that switching to a Mediterranean diet lowered heart disease recurrence risk by 22% compared to a low-fat diet.
- Number needed to treat (NNT) = 20 → For every 20 people who follow the Mediterranean diet for 7 years, one major cardiovascular event is prevented.
How the Mediterranean Diet Protects the Heart:
The Mediterranean diet works by:
- Lowering inflammation with polyphenols from extra-virgin olive oil.
- Improving cholesterol levels by increasing HDL and reducing LDL oxidation.
- Enhancing blood vessel function and reducing atherosclerosis progression.
- Stabilizing blood sugar levels, reducing diabetes risk (which is a major contributor to heart disease).
Related Studies and Research
Mediterranean Diet and Heart Disease – Explores the role of the Mediterranean diet in reducing cardiovascular risk and improving heart health.
Mediterranean Diet and Heart Disease: A Primary Prevention Study – Analyzes research on how the Mediterranean diet affects heart disease risk in individuals without prior cardiovascular events.
Frequently Asked Questions:
Is the Mediterranean diet hard to follow?
Not at all! It’s a flexible diet rich in natural, whole foods. Simple swaps—like using olive oil instead of vegetable oil—can make a big difference.
Do I need to track calories on this diet?
No. Unlike many other diets, the Mediterranean diet focuses on food quality rather than calorie counting.
Can this diet help if I already have heart disease?
Yes! This study specifically looked at secondary prevention—meaning it tested how diet affects people who already have heart disease. The results showed significant benefits, reducing future heart attacks and strokes.
Does the Mediterranean diet help with weight loss?
The study didn’t focus on weight loss, but both groups had similar weight changes. The primary benefits were heart protection and better metabolic health.
Conclusion:
The CORDIOPREV study confirms that a Mediterranean diet rich in extra-virgin olive oil is more effective than a low-fat diet at preventing heart disease recurrence. The absolute risk reduction of 4.9% means real-world benefits for people at high risk of cardiovascular events.
If you have heart disease—or want to prevent it—switching to a Mediterranean diet could be one of the most powerful changes you make for your health.