Does the Mediterranean diet help you live longer?

People who closely follow the Mediterranean diet die prematurely less often. In a Greek cohort of more than 22,000 adults, every two-point increase in dietary adherence on a 10-point scale was associated with a 25% lower risk of death. Mortality from heart disease was 33% lower, and from cancer 24% lower. This is observational research, so a direct causal relationship has not been proven. Lifestyle, income and general health can all colour the figures¹.

The strongest evidence concerns cardiovascular disease and related risk factors such as high blood pressure, poor blood lipids and excess weight. Both observational studies and intervention studies find a beneficial effect here, which makes a causal relationship more plausible than for other outcomes. For anyone wanting to prevent cardiovascular disease or improve risk factors, this is the best-supported dietary pattern currently available^2,3.

For type 2 diabetes there are positive signals: a lower chance of developing it, and better blood sugar control in those who already have it. For cognitive decline and Alzheimer's disease there are observational signals, but these are not yet strong enough to support a causal relationship^2,3,4.

When the Mediterranean diet is combined with sufficient physical activity and not smoking, large cohort studies show a 8 to 10 year longer disease-free life expectancy. The individual contribution of the diet has not been separated from the other factors in those studies. That figure therefore cannot be attributed to the diet alone⁵.

The so-called Blue Zones, such as Sardinia and Ikaria, are often cited as evidence that this diet extends life. Researchers caution, however, that the dietary patterns there are not uniform and change over time. Social connection, physical activity and genetics likely also play a major role. That the diet alone is responsible for the high ages reached in those regions has not been sufficiently demonstrated⁶.