Tomatoes have long been recognized for their extensive array of health benefits, ranging from safeguarding against cancer and hypertension to promoting the well-being of our hearts, skin, and eyes.
One crucial component responsible for these benefits is lycopene, a potent plant compound abundantly found in tomatoes. Previous research has established a connection between lycopene intake and a decreased risk of various cancers, including prostate, colon, and lung cancer.
However, recent findings from a small-scale study shed light on a lesser-known factor that influences the cancer-fighting prowess of lycopene-rich foods. It appears that the combined consumption of iron-rich foods or supplements may potentially diminish the remarkable effects of lycopene.
The study, led by Rachel Kopec, an esteemed assistant professor of human nutrition at Ohio State University in Columbus, highlights this intricate interaction. Published in the esteemed journal Molecular Nutrition & Food Research, the research emphasizes the significance of considering nutrient combinations when aiming to maximize the benefits of lycopene in cancer prevention.
In the study conducted by Kopec and his colleagues, the focus was placed on investigating the “creation and assimilation of lycopene metabolites” among a group of seven male subjects who consumed test meals containing tomato extract. This study also explored the impact of iron on the process.
The participants were provided with a specially formulated shake, which they consumed in two variations: one supplemented with ferrous sulfate as an iron source, and the other without any iron supplementation. To gather valuable insights, the researchers diligently analyzed the blood and digestive fluids of the participants.
By meticulously examining the interplay between lycopene metabolites and iron, this study offers a comprehensive understanding of their intricate relationship and sheds light on previously unexplored aspects of this field.
Participants who had an iron-rich meal, the authors noticed “almost a twofold drop in lycopene uptake over time,” said Kopec.
“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,” remarked the author.
While it has been known that iron can destroy certain compounds when mixed, the impact on potentially beneficial carotenoids, such as lycopene found in fruits and vegetables, remained a mystery until now.
Carotenoids, plant-derived pigments responsible for yellow, orange, and red hues, are prevalent in the Western diet. Some of the most common carotenoids include alpha-carotene, beta-carotene, lutein, and lycopene.
While these pigments possess antioxidant properties, researchers have yet to ascertain whether their potential in fighting cancer stems from their antioxidant content or other compounds unrelated to antioxidants.
Regarding the recent study, the exact mechanisms behind iron’s ability to dilute lycopene also remain unknown. One possibility is that iron oxidizes lycopene, leading to the formation of metabolites distinct from apo-lycopenoids, which were the primary focus of this investigation.
Kopec suggested another theory: “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 added.
The study authors acknowledge limitations, including the use of exclusively male participants and the exclusive focus on apo-lycopenoids, which restricts the generalizability of the findings.
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