This week on the Olive Health Information System website

The newsletter of the University of Navarra and the IOC dedicated to health

Article 1

This week’s newsletter explores two recent systematic reviews and meta-analyses assessing the effectiveness of the Mediterranean diet in the management of metabolic and neurological conditions. The Mediterranean diet is a predominantly plant-based eating pattern rich in fruits, vegetables, whole grains, legumes, nuts, and seeds, with olive oil as the principal source of dietary fat. It is widely recognized for its cardiometabolic and overall health benefits.

The first analysis focused on metabolic outcomes and found that greater adherence to the Mediterranean diet was associated with small to moderate reductions in body mass index and waist circumference in specific populations, particularly individuals with non-alcoholic fatty liver disease and those with metabolically healthy obesity. Mortality outcomes were evaluated in three cohort studies including 369,220 participants with type 2 diabetes and metabolic syndrome, with follow-up periods ranging from 4 to 12.3 years. Each one-point increase in Mediterranean diet adherence score was associated with a 7% reduction in all-cause mortality (hazard ratio 0.93; 95% confidence interval (CI) 0.90–0.97).

The second meta-analysis included both observational and interventional studies examining adherence to the Mediterranean diet in relation to neurological diseases. A total of 45 studies involving more than 730,000 participants were analyzed. Higher adherence to the Mediterranean diet was associated with a lower risk or prevalence of Alzheimer’s disease (odds ratio 0.92; 95% CI 0.87–0.98), mild cognitive impairment (relative risk 0.93; 95% CI 0.88–0.98), depression (relative risk 0.96; 95% CI 0.94–0.97), and Parkinson’s disease (relative risk 0.90; 95% CI 0.83–0.97).

Overall, this growing body of evidence supports the promotion of Mediterranean-style dietary patterns as a viable public health strategy for the secondary prevention and management of metabolic diseases and neurodegenerative disorders. In particular, the consistent inverse association with all-cause mortality in people with diabetes, together with the reduced risk of cognitive decline, reinforces the value of integrating Mediterranean diet protocols into standard care guidelines.

Article 2

Extra virgin olive oil and the Mediterranean diet continue to attract attention in health research, not only for their cultural and culinary value but also for their well-documented health benefits. A recent experimental study highlighted the importance of olive oil polyphenol content, showing that phenolic-rich oils more effectively reduce oxidative stress, modulate inflammation, and promote cholesterol efflux—key mechanisms for cardiovascular protection. The findings reinforce that the quality of extra virgin olive oil is just as important as the quantity consumed.

Beyond cardiovascular health, the potential benefits of the Mediterranean diet—and its key components, including extra virgin olive oil—extend to brain ageing. In this context, an analysis of the MIND diet, designed to reduce cognitive decline, found that higher adherence was associated with better cognitive performance overall. Interestingly, associations differed by race, with positive findings among White participants and inverse associations among Black participants, highlighting the need to interpret these results in light of underlying social, cultural, and socioeconomic influences.

Finally, shifting the focus to immune-related outcomes, a recent systematic review and meta-analysis examined whether the Mediterranean diet may help prevent autoimmune diseases. While no significant associations were found for conditions such as rheumatoid arthritis, lupus, or inflammatory bowel disease, promising signals emerged for multiple sclerosis and Sjögren’s syndrome. However, the evidence remains limited, underscoring the need for further well-designed studies to clarify these associations.

Overall, current evidence continues to position the Mediterranean diet as a solid public health approach to chronic disease prevention and the promotion of overall well-being.