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Spanish scientists found cooked tomato sauce boosts the levels of healthy bacteria in the gut and ­tomatoes have a better probiotic effect when fried into a sauce, rather than when eaten raw.

Researchers at the Universitat Politècnica de València (UPV) belonging to the Food Development Engineering Institute (IUIAD) and the Advanced Centre on Food Microbiology have evaluated the impact certain antioxidants in tomatoes, phenolic compounds and lycopene, have on the viability of the probiotic microorganism L reuteri, and vice versa, throughout the digestive process.

They found that lycopene can be more readily utilized by the body if the ­tomatoes are cooked and especially if they’re concentrated, like when you make a pasta sauce, or in the form of ketchup (watch the sugar).

“We have evaluated the viability of the probiotic strain along the digestive process individually and the presence of antioxidants from vegetable sources, as well as the impact of the probiotic strain on the changes suffered by antioxidant compounds and the resulting bioaccessibility. We worked with raw and fried tomato to determine the impact of processing. And among the results, we found that serving meals rich in probiotics with fried tomato sauce boosts its probiotic effect; as well as causing a progressive isomerisation of the lycopene of the tomato, from form cis to trans throughout digestion, which positively results in an increased final bioaccessibility of this carotenoid,”

– Ana Belén Heredia, a researcher at the IUIAD of the UPV.

The cooked tomato sauce was better than raw tomatoes because cooking preserves the lycopene and also makes it more concentrated. This is important because it means more of the lycopene survives the digestive process and goes on to be absorbed by the body.

This is actually not the first study to show that cooked tomatoes increase the availability of lycopene, but what has previously been shown (e.g 2002, 2007, 2010 etc) now is also tied to interaction with L. reuteri and how cooked tomatoes put the brakes on a gastric cancer cell’s ability to spread and develop, as well as leading to their death.

The researchers say their findings could lead to studies on preventing stomach cancer, as well as using diet to support conventional cancer treatments.


J.García-Hernández et al. Tomato-antioxidants enhance viability of L. reuteri under gastrointestinal conditions while the probiotic negatively affects bioaccessibility of lycopene and phenols