A study led by King’s College London found that the combination of olive oil and salad holds the key to keeping the risk of high blood pressure down.
A large salad with a simple dressing combines the necessary unsaturated fats with nitrate-rich vegetables.
The findings were published in journal Proceedings of the National Academy of Sciences in the USA by scientists at Kings College, the University of California and University of Pittsburgh.
They suggest that the protective effect of the Mediterranean diet comes from the nitro fatty acids it generates, which inhibit an enzyme linked to high blood pressure.
A Mediterranean diet typically includes unsaturated fats found in olive oil, nuts and avocadoes, along with vegetables like spinach, celery and carrots that are rich in nitrite and nitrates.
Lettuce is high in nitrate, which combines with unsaturated fat to keep blood pressure low When the compounds in these two food groups are combined, they can form nitro fatty acids.
The study used mice to investigate how the acids lower blood pressure by seeing whether they inhibited an enzyme called epoxide hydrolase, which can raise blood pressure.