COLUMBUS, Ohio — There are certain food pairings that were just meant to be. Peanut butter and jelly, bacon and eggs, and spaghetti with meatballs immediately come to mind as a few examples of quintessential food couples. However, a new study finds that if you top your spaghetti and meatball dinner with a jar of tomato sauce, you may want to skip the meatballs entirely should you want to reap all the health benefits from the meal.
That’s because tomatoes are known to boast anti-cancer properties, thanks to a compound found inside the fruit called lycopene. But researchers at The Ohio State University say that the lycopene found in tomato sauce can be neutralized if eaten with iron-rich foods such as meatballs.
To come to their conclusions, researchers took blood and digestive fluid samples from a small group of medical students. Participants were separated into two groups; one group drank a tomato extract-based shake with iron before samples were taken, and the other group drank a tomato extract shake with no iron supplements included.
After analyzing the samples, it was discovered that students who had drank the tomato shake with iron displayed significantly lower levels of lycopene in their blood and fluid samples.
“When people had iron with their meal, we saw almost a twofold drop in lycopene uptake over time,” comments lead author Rachel Kopec, an assistant professor of human nutrition at Ohio State, in a release. “This could have potential implications every time a person is consuming something rich in lycopene and iron – say a Bolognese sauce, or an iron-fortified cereal with a side of tomato juice. You’re probably only getting half as much lycopene from this as you would without the iron.”
The research team say that iron’s relationship with the human body is a complicated one. On one hand, it is an integral part of a healthy diet and allows us to produce energy and rid ourselves of waste, but iron can also interfere with other cellular processes in the body.
“We know that if you mix iron with certain compounds it will destroy them, but we didn’t know if it would impair potentially beneficial carotenoids, like lycopene, found in fruits and vegetables,” Kopec explains.
Lycopene is a cerotenoid, or a natural pigment responsible for many of the vibrant colors found in fruits like watermelons, pink grapefruits, and of course, tomatoes. Previous research has found lycopene to have potential anti-cancer benefits across numerous types of cancer, including lung, skin, and prostate.
The study’s authors aren’t sure exactly why iron is interfering with lycopene uptake, but it may be because iron oxidizes lycopene, resulting in a different metabolic product.
“It’s also possible that iron interrupts the nice emulsified mix of tomato and fats that is critical for cells to absorb the lycopene. It could turn it into a substance like separated salad dressing – oil on top and vinegar on the bottom – that won’t ever mix properly,” Kopec says. “Nutrition can play an important role in disease prevention, but it’s important for us to gather the details about precisely how what we eat is contributing to our health so that we can give people reliable, science-based recommendations,”
The study is published in Molecular Nutrition & Food Research.