UK Study: Mediterranean Diet Cuts Type 2 Diabetes Risk by 29%

UK Study: Mediterranean Diet Cuts Type 2 Diabetes Risk by 29%

A study from the United Kingdom has delivered some of the strongest objective evidence yet that following a Mediterranean diet can significantly reduce your risk of developing type 2 diabetes (T2D) — and the findings have direct relevance for the millions of Americans living with or at risk for diabetes.

What Researchers Did — and Why It's Different

Scientists at the MRC Epidemiology Unit, University of Cambridge analyzed data from over 22,000 European adults, including 9,453 people who developed type 2 diabetes over an average follow-up of nearly 10 years. What sets this study apart is how they measured diet: instead of relying on participants to accurately recall and report what they ate — a notoriously unreliable method — the Cambridge team developed a blood biomarker score based on 5 circulating carotenoids (plant pigments found in colorful fruits and vegetables) and 24 fatty acids. Think of it as a biological fingerprint of what you actually ate, not just what you remembered eating.

The biomarker score was first validated in the MedLey randomized controlled trial, where it successfully distinguished participants who followed a Mediterranean diet from those who didn't, achieving an impressive accuracy score (C-statistic) of 0.88 out of 1.0. The researchers then applied this scoring tool to the large EPIC-InterAct case-cohort study to examine real-world diabetes outcomes.

Key Findings

The results were striking. People whose blood biomarkers reflected stronger adherence to the Mediterranean diet had a 29% lower risk of developing type 2 diabetes (hazard ratio: 0.71) compared to those with lower adherence. In contrast, when the same researchers used traditional self-reported diet questionnaires, the benefit appeared much smaller — only about 10% risk reduction. This suggests that previous studies relying on self-reported data may have significantly underestimated how protective the Mediterranean diet actually is.

Even modest improvements matter: the researchers estimated that increasing Mediterranean diet adherence by just 10 percentile points across a population could reduce new T2D cases by approximately 11%.

Why This Matters for US Patients

The United States currently has over 37 million people living with diabetes, and another 96 million adults with prediabetes — the majority of whom don't know it. The American Diabetes Association (ADA) already recommends the Mediterranean diet as one of several healthy eating patterns for diabetes prevention and management. However, most supporting studies have depended on self-reported food diaries or questionnaires. This UK research provides objective, blood-based confirmation that the diet works — and works better than we previously thought.

For US patients, the Mediterranean diet means focusing on vegetables, fruits, whole grains, legumes, nuts, olive oil, fish, and moderate amounts of poultry and dairy, while limiting red meat and processed foods. No exotic ingredients are required — many staples are widely available and affordable across the US.

It's also worth noting a practical blood sugar reference point: while this study tracked diabetes incidence rather than blood glucose levels directly, US guidelines define prediabetes as fasting blood sugar of 100–125 mg/dL (5.6–6.9 mmol/L) and diabetes at 126 mg/dL (7.0 mmol/L) or above. Dietary interventions like the Mediterranean diet are a frontline strategy to keep those numbers in check.

Study Limitations

The authors acknowledge that biomarker measurement isn't perfect, the score may not be entirely specific to the Mediterranean diet, and some confounding lifestyle factors may remain unaccounted for. The study population was primarily Western European, so results may not translate identically across all US demographic groups.

Bottom Line

This rigorous UK research confirms what many clinicians have long suspected: the Mediterranean diet is a powerful, evidence-backed tool for reducing type 2 diabetes risk — and its benefits may be even greater than previously measured. Talk to your MDS Diabetes care team about how to incorporate Mediterranean eating principles into your daily routine.

Source: Sobiecki, Imamura, Davis. "A nutritional biomarker score of the Mediterranean diet and incident type 2 diabetes." PLOS Medicine, 2023. PMID: 37104291. DOI: 10.1371/journal.pmed.1004221