25 September 2019

Your meatballs may taste good with tomato sauce, but this could have an unusual health downside

While it makes for a hearty meal, iron-rich foods with tomato sauce may deprive you of some critical health benefits, new research has found.

Tomatoes are known as 'the powerful little fruit' because of their numerous health benefits. These include:

A previous Health24 article notes that tomatoes contain lycopene – the red pigment also found in fruits and vegetables such as watermelon and red chillies. Lycopene helps to fight cancer, especially prostate, lung and skin cancers.

Lycopene is also an antioxidant (a substance that protects against cell damage) and has been found to be the most potent antioxidant among various common carotenoids. (Carotenoids are plant pigments with antioxidant properties, such as lycopene.)

Lycopene levels drop with iron-rich foods

Enjoying your tomatoes as a sauce with meatballs may, however, remove its anti-cancer properties.

Researchers from the Ohio State University had a small group of seven French medical students consume a tomato extract-based shake with or without iron. Their blood and digestive fluids were then analysed.

The results showed that when students drank the liquid meal mixed with the iron supplement, lycopene levels in the digestive fluid and blood were significantly lower in comparison to the students who did not have the iron supplement in their shake.

“When people had iron with their meal, we saw almost a twofold drop in lycopene uptake over time,” explained Rachel Kopec, assistant professor of human nutrition at Ohio State and also the study’s lead author.

Kopec added that this could have potential implications every time a person consumes something rich in lycopene and iron, such as 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,” she explained.

Iron’s downside

Iron plays an important role in the body and is an essential part of our diet, but this nutrient can also interfere with other cellular-level processes.  

“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 said.

Kopec added that one of two things could be happening:

  • The meal with iron oxidises the lycopene, creating different products of metabolism.
  • The iron interrupts the emulsified mix of tomato and fats (and this is critical for cells to absorb the lycopene).

While researchers continue to further an understanding of lycopene’s role in fighting cancer and its interplay with other compounds and nutrients, it’s best to entirely separate your tomatoes from any iron-rich foods (like meatballs) if you want the full health benefits of this nutrient. 

Image: iStock


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