People on such a diet with low amounts of animal-based products like meat and milk have a 20 percent higher chance of living longer with an estimated average of two to three years, The Telegraph reports.
The health benefits have long been known, but now scientists have studied the effects on older people, using a unique study to compare thousands of 70-year-olds who eat the diet with others who have eaten more meat and animal products.
Known as the 'H70' study, it has studied 70-year-olds for more than 40 years.
These results are supported by three further studies into Mediterranean diets and their health effects, one of which was on children, the newspaper said.
Gianluca Tognon, a scientist at the University of Gothenberg, Sweden, said: 'This means in practice that older people who eat a Mediterranean diet live an estimated two to three years longer than those who don't.
'The conclusion we can draw from these studies is that there is no doubt that a Mediterranean diet is linked to better health, not only for the elderly but also for youngsters.'
The study is published in the journal Age.