The Mediterranean diet is one of the dietary patterns with the strongest scientific support for chronic disease prevention, owing to the synergistic combination of plant-based foods, fish, nuts, and olive oil as the primary source of dietary fat. Recent evidence further reinforces that its benefits extend beyond cardiovascular health to include glycemic metabolism, neurological function, and other processes involved in healthy ageing.

A recent meta-analysis of 51 randomized controlled trials provides robust evidence on the role of olive oil in glucose metabolism. A daily intake of 25–50 g of olive oil was associated with significant improvements in insulin resistance, assessed by HOMA-IR, while no significant changes were observed in markers of overall glycemic control, such as fasting glucose or HbA1c. These findings suggest that olive oil may exert early effects on mechanisms of insulin resistance—possibly through anti-inflammatory and antioxidant pathways—without necessarily translating into direct improvements in established glycaemia, particularly in individuals without advanced diabetes. 

The metabolic benefits of the Mediterranean pattern are paralleled by effects in the neurological domain. The prospective E3N study examined the association between adherence to the Mediterranean diet and the MIND diet and the incidence of Parkinson’s disease in a large cohort of women. Higher adherence was associated with a lower incidence of Parkinson’s disease in women younger than 71 years, supporting a sustained neuroprotective effect over time in this age group.

These protective associations are not confined to the neurological domain and appear to be strengthened when the Mediterranean diet is embedded within a comprehensive lifestyle framework. Further support comes from longitudinal data from the UK Biobank, where higher adherence to the MEDLIFE index—reflecting adherence to the Mediterranean diet together with Mediterranean-style lifestyle behaviors—was associated with a reduced risk of cataracts and age-related macular degeneration. In contrast, the lower risk of glaucoma was mainly driven by non-dietary lifestyle factors, such as physical activity, rest, and social engagement, highlighting the importance of a comprehensive lifestyle approach.

Together, these complementary high-quality studies reinforce the Mediterranean diet as an effective strategy for both primary and secondary prevention. Olive oil, as a central pillar of this pattern, emerges as a key contributor to metabolic regulation, neuroprotection, and the reduction of age-related damage.