Higher consumption of tomatoes could be associated with a decreased risk of liver cancer caused by high-fat diets, a study has found.

The study, conducted on mice, showed that tomatoes are rich in lycopene -- a strong antioxidant, anti-inflammatory and anti-cancer agent -- which helps in effectively reducing fatty liver disease, inflammation and liver cancer development.

"Consuming whole foods like tomatoes and processed tomatoes from sauces, tomato paste, canned whole tomato products, ketchup and juice, provides the best source of lycopene," said Xiang-Dong Wang, Professor at Tufts University in the US.

Interestingly, we observed that tomato powder is more effective than the same dose of purified lycopene supplementation to prevent liver cancer development, said Wang. This could be due to the potential beneficial effects of other nutrients in a whole tomato, such as vitamin E, vitamin C, folate, minerals, phenolic compounds and dietary fibres.

In addition, feeding mice tomato powder increased the richness and diversity of beneficial microbiota and prevented the over-growth of some bacteria related to inflammation, said the study, published in the journal Cancer Prevention Research.

For the study, infant mice were infected with a liver carcinogen and then fed an unhealthy high-fat diet similar to a Western diet, with or without tomato powder containing lycopene. Other foods including guava, watermelon, grapefruit, papaya, and sweet red pepper also contain lycopene, but in much lower concentrations compared to tomatoes.

Eating tomatoes and tomato products such as tomato sauce rich in lycopene is also associated with a lower risk of cardiovascular disease, osteoporosis, diabetes, and certain cancers, including prostate, lung, breast and colon cancer, the study showed.