Nutrition
The Mediterranean diet reduces cardiovascular mortality
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Ainhoa Pérez
Alumni
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MPH, MSc.
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A recent systematic review of studies has analyzed the effect of the Mediterranean diet on cardiovascular disease, showing protective effects, particularly in patients with previous cardiovascular disease. Discover how the Mediterranean diet impacts cardiovascular health.
However, the meta-analyses included have relevant methodological limitations. Only three of the 18 reviews were rated as moderate quality; the rest were considered low or critically low quality. Despite the clinical relevance of outcomes such as all-cause mortality and cardiovascular mortality, these were based on a very limited number of clinical trials. In addition, many of the controlled studies included in the original reviews did not have an adequate assessment of risk of bias. Methodological justifications for exclusions were also omitted, and less rigorous methods of synthesis were applied. Despite these limitations, the available evidence supports the integration of the Mediterranean diet into clinical interventions for cardiovascular risk reduction, especially in patients with established disease. Additional well-designed clinical trials are needed to allow more robust conclusions about the size of the effect, focusing specifically on mortality outcomes rather than intermediate markers. Additionally, they should consider specific subgroups such as people with diabetes, hypertension, kidney disease, and other conditions of interest.
PATHOPHYSIOLOGY AND MECHANISMS
Cardiovascular disease is the leading cause of morbidity and mortality worldwide, driven largely by modifiable risk factors. The Mediterranean diet, based on high consumption of vegetables, legumes, fruits, whole grains, nuts, and extra virgin olive oil, along with moderate intake of fish, seafood, and fermented dairy products and low consumption of red and processed meats, has been widely studied as a preventive strategy. Its protective effect is attributed to the synergistic action of its dietary components, with vascular, anti-inflammatory, antioxidant, and microbiota effects, among others. Clinical trials such as PREDIMED have shown reductions in cardiovascular events and mortality in people without previous disease, while in secondary prevention, studies such as CORDIOPREV and the Lyon Diet Heart Study have yielded similar results, consolidating this dietary pattern as one of the most robustly supported in preventive cardiology.STUDY
An umbrella review of systematic reviews of clinical trials (Hareer et al., 2025) evaluated the effects of the Mediterranean diet on primary and secondary prevention of cardiovascular disease. Eighteen meta-analyses were included, covering 238 clinical trials from different countries with a total of almost 200,000 adults. The interventions compared the Mediterranean diet with other dietary patterns, such as low-fat diets, DASH, low-carbohydrate diets, standard dietary recommendations, or other strategies. Although the definition of "Mediterranean dietâ" is not uniform, it generally involves recommendations for high consumption of fresh plant foods and the use of olive oil, with low intake of processed foods and red meat. The review evaluated clinical outcomes such as absolute mortality, cardiovascular mortality, non-fatal myocardial infarction, and major cardiovascular events. Additional intermediate parameters such as blood pressure, lipid profile, blood glucose, and anthropometric measures were also evaluated.MAIN RESULTS
The results showed significant reductions in cardiovascular mortality, especially in secondary prevention, as well as in the number of cardiovascular events such as myocardial infarction. A decrease in the risk of stroke was also observed, which may be a greater effect in people with type 2 diabetes. In primary prevention, the effects were less consistent and, in some cases, not statistically significant. Improvements in multiple cardiovascular risk biomarkers were also documented: decreased blood pressure, reduced total cholesterol, LDL, and triglycerides, and improved glycemia, glycosylated hemoglobin (HbA1c), and fasting insulin levels, although with greater heterogeneity between studies in some of these markers. The effects were more consistent in longer studies and in Mediterranean regions.CONCLUSION AND CLINICAL RELEVANCE
Overall, the data support the inclusion of the Mediterranean diet in clinical strategies to reduce cardiovascular risk, with a greater impact in patients with established disease, possibly due to their higher baseline risk. These results are consistent with previous findings from trials such as PREDIMED, CORDIOPREV, and the Lyon Diet Heart Study. Although the review did not directly compare different dietary patterns, the results of the included meta-analyses suggest that the Mediterranean diet may have similar effects to other structured diets such as the DASH diet, as no statistically significant differences were observed. This implies, as is evident, that the quality of the foods included, and not the dietary label of one diet or another, is responsible for the effect. Consistently, at the research level, the difficulties in drawing conclusions are related to the lack of qualitative assessments of dietary patterns. At the clinical level, this implies that any diet high in vegetables, fruits, nuts, fats such as extra virgin olive oil, etc., and low in processed and refined foods will be protective in people with cardiovascular risk. The reduction in cardiovascular risk, as measured by a decrease in events and mortality, does not necessarily depend on achieving reductions in blood lipids, as shown by the Lyon Heart Study. Nor does it depend on eating a low-fat diet, although it does depend on prioritizing fats such as extra virgin olive oil and some nuts.However, the meta-analyses included have relevant methodological limitations. Only three of the 18 reviews were rated as moderate quality; the rest were considered low or critically low quality. Despite the clinical relevance of outcomes such as all-cause mortality and cardiovascular mortality, these were based on a very limited number of clinical trials. In addition, many of the controlled studies included in the original reviews did not have an adequate assessment of risk of bias. Methodological justifications for exclusions were also omitted, and less rigorous methods of synthesis were applied. Despite these limitations, the available evidence supports the integration of the Mediterranean diet into clinical interventions for cardiovascular risk reduction, especially in patients with established disease. Additional well-designed clinical trials are needed to allow more robust conclusions about the size of the effect, focusing specifically on mortality outcomes rather than intermediate markers. Additionally, they should consider specific subgroups such as people with diabetes, hypertension, kidney disease, and other conditions of interest.
#Mediterraneandiet #cardiovasculardisease #highbloodpressure #stroke
References:
Hareer, L. W etl, al, 2025. The effectiveness of the Mediterranean Diet for primary and secondary prevention of cardiovascular disease: An umbrella review. Nutrition & Dietetics, 82(1), 8-41. https://doi.org/10.1111/1747-0080.12891
* The news published on studies do not represent an official position of ICNS, nor a clinical recommendation.
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