Several years ago, Schwartz and his colleagues discovered the abundance of several of these isomers, called cis- lycopenes, in human blood. But most of the tomatoes and tomato-based products we currently consume are rich in all-trans-lycopene.
"We don't know why our bodies seem to transform lycopene into cis-isomers, or if some isomers are more beneficial than others," Schwartz said.
The researchers don't know if tomatoes rich in cis-lycopene would provide greater health benefits to humans, but the study's results suggest that tomatoes can be used to increase both the intake and absorption of the health-beneficial compounds.
The researchers made spaghetti sauce from two tomato varieties ?tangerine tomatoes, which get their name from their orange skin and are high in cis-lycopene, and a tomato variety chosen for its rich beta carotene content.
The tomatoes were grown at an Ohio State-affiliated agricultural research station in northwestern Ohio. Following harvest, both tomato varieties were immediately processed into canned tomato juice and concentrated. Italian seasoning was added for taste.
The 12 adults participating in the study ate two spaghetti test meals ?one included sauce made from tangerine tomatoes, while the other featured sauce made from the tomatoes high in beta carotene. The participants were asked to avoid tomato and beta carotene-rich foods for 13 days before eating each test meal.
Researchers drew blood right before each participant ate and again every hour or two up to 10 hours after the meal. They analyzed the blood samples for lycopene and beta carotene content.
Lycopene absorption from the tangerine tomatoes was 2.5 times higher than that ab
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Source:Ohio State University