Increases in plasma lycopene concentration after consumption of tomatoes cooked with olive oil.

Lycopene is the main carotenoid in tomatoes and it has been hypothesised to be responsible for reducing the risk of some cancers and heart disease. The cooking of tomatoes with olive oil is a characteristic combination in the Southern Mediterranean diet. Previous studies have shown that the absorption of lycopene is greater from processed tomatoes than fresh tomatoes, since the processing breaks down the tomato cell matrix and makes the lycopene more available. The aim of the present study was to determine whether consumption of diced tomatoes cooked with olive oil resulted in higher plasma lycopene concentrations than consumption of diced tomatoes cooked without olive oil. Plasma lycopene concentrations were measured after 5 days on a low lycopene diet and again after a five-day dietary intervention, in healthy subjects, who consumed one meal per day of tomatoes (470 g) cooked with or without extra virgin olive oil (25 ml olive oil). There was an 82% increase in plasma trans-lycopene (P< 0.001) and a 40% in cis-lycopene (P = 0.002) concentrations in the 11 subjects who consumed tomatoes cooked in olive oil. There was no significant change in trans-lycopene (P = 0.684) and a 15% increase in cis-lycopene (P = 0.007) concentrations in 12 subjects consuming tomatoes cooked without olive oil. We conclude that the addition of olive oil to diced tomatoes during cooking greatly increases the absorption of lycopene. The results highlight the importance of cuisine (i.e how a food is prepared and consumed) in determining the bioavailability of dietary carotenoids such as lycopene.