A silent liver disease epidemic is sweeping Britain that has nothing to do with heavy drinking. Now experts think the humble tomato could help fight its devastating effects

When we think of health warnings linked to liver damage, alcohol usually steals the headlines. But a silent epidemic is sweeping Britain that has nothing to do with heavy drinking.

Metabolic dysfunction-associated steatotic liver disease (MASLD), or fatty liver disease, affects around one in four adults.

Yet this could be an underestimate as it often causes no symptoms until liver damage is advanced.

Driven by rising rates of obesity, the condition occurs when excess fat builds up inside liver cells. Left unchecked, it can lead to dangerous inflammation, irreversible scarring (cirrhosis) and liver failure.

Yet a clue to tackling this growing health problem could be hiding in the humble tomato.

Scientists have known for decades that tomatoes contain lycopene, the vibrant red antioxidant pigment linked to benefits ranging from better heart health to a reduced risk of prostate cancer.

But researchers are now turning their attention to another tomato compound that has largely escaped the spotlight: phytoene, which is part of the same family of compounds as lycopene, but colourless.

Researchers became interested in phytoene after animal studies suggested that the health benefits were not just from lycopene alone, hinting that other compounds play an important role.

In a new study published in Molecular Nutrition & Food Research, researchers at Tufts University, in Boston, looked specifically at phytoene.

The US scientists found that when mice were fed the same diet – high in refined carbohydrates (to trigger fatty liver disease) – those also given daily phytoene supplements, equivalent to the amount in three to four medium-sized tomatoes, developed significantly less fat in their livers.

Researchers found that phytoene increased levels of key proteins, SIRT1 and AMPK, which help regulate how the liver burns fat for energy – suggesting the liver was better able to process fat rather than allowing it to accumulate.

‘The liver-protective effects appear to come from active compounds produced when the body breaks down phytoene,’ explains Professor Xiang-Dong Wang, an expert in nutrition and carotenoid metabolism, who led the study.

The researchers concluded that phytoene-rich foods and supplements warrant further investigation as a way to help prevent fatty liver disease.

Professor Wang told Good Health: ‘Next, we need to conduct clinical trials of products enriched in phytoene on people with diabetes, obesity and fatty liver disease – to see how this component can improve metabolic health.’

This is not the only recent evidence linking tomatoes and liver health.

In July, a small trial in Italy provided encouraging evidence that eating tomatoes may benefit people already affected by fatty liver disease.

Published in the journal Nutrients, the study found that adults with MASLD who consumed 200g of raw tomatoes (roughly two to three medium tomatoes), plus 50g (three tablespoons) of passata (a tomato sauce), daily for six weeks, experienced a significantly greater reduction in liver fat than people who did not add tomatoes to their diet.

The researchers said tomato compounds influence how fat is produced, stored and burned in the liver, while also helping to reduce disease-causing inflammation. But they did not specify which compounds were responsible for the benefits.

There may be benefits beyond liver health.

In a trial by Heinrich Heine University in Düsseldorf, Germany, and the University of Dundee, adults given capsules containing tomato carotenoids, including phytoene, developed less skin redness after controlled UV exposure than those taking a placebo.

The compounds are thought to help reduce some of the cell damage and inflammation associated with the sun’s harmful rays.

There are simple ways to maximise the amount of beneficial compounds such as phytoene that your body absorbs from foods.

Phytoene is found throughout the tomato’s flesh and within plant cells, so both fresh and processed tomato products can contribute to intake.

And like lycopene, phytoene is fat-soluble, meaning it is absorbed more efficiently when tomatoes are eaten with a source of fat such as olive oil.

Cooking and processing can help too. Tomato purée, passata and tomato paste provide concentrated sources of beneficial carotenoids because heating and processing break down plant cell walls, making these compounds easier for the body to absorb.

And tomatoes are not the only source of phytoene.

The compound occurs naturally in a variety of colourful fruit and vegetables, as it is involved in making pigment-producing compounds, such as lycopene – these include carrots (which are actually a richer source than tomatoes), as well as apricots, peaches, watermelon and citrus fruits.

Commenting on the emerging findings, Duane Mellor, a dietitian and researcher at Aston University, says: ‘The science around phytoene remains an intriguing scientific lead rather than something that can be translated into dietary recommendations.

‘The new findings certainly provide another reason to keep tomatoes on the menu.’

He adds: ‘Tomatoes, particularly when lightly fried in olive oil and garlic as part of a traditional sofrito [a base for beans, sauces and stews], are seen by many as a cornerstone of the Mediterranean diet – and what we are most confident about is that Mediterranean-style diets are associated with a lower risk of fatty liver disease.

‘Tomatoes are just one part of that bigger picture.’

But the broader message remains a familiar one, he says: ‘A colourful, plant-rich diet is still one of the best ways to support long-term health, including a healthy liver.’