Tomatoes and Liver Fat: The POMOSANO Trial, Explained

2026-08-09 · FattyLiverFood Research Team

On August 8, 2026, researchers at the Italian National Institute of Gastroenterology published the POMOSANO trial in Nutrients. The design was small and clean: 79 adults with mild-to-moderate MASLD, average age 58, not obese, were randomized to either 200 grams of fresh tomatoes plus 50 grams of tomato sauce every day for six weeks, or no tomato intervention. Liver fat was measured with FibroScan's CAP score before and after.

The result: the tomato group's CAP dropped an average of 35 dB/m, versus 18 dB/m in the control group - roughly double the improvement. The effect held after adjusting for age, sex, and BMI. And critically, the two groups showed no significant difference in weight, waist circumference, visceral fat, blood sugar, or inflammation markers. The liver benefit did not come from weight loss. The authors pointed to lycopene, beta-carotene, and other bioactive compounds as likely drivers, possibly working through the SIRT1-AMPK pathway to curb de novo lipogenesis and speed fat oxidation.

What a 35 dB/m CAP change means

CAP is a surrogate for liver fat measured by ultrasound-based elastography. A 35 dB/m drop over six weeks is a meaningful shift in the steatosis range - the kind of change that, sustained over months, moves a person from a higher steatosis grade toward a lower one. The study is small and short, and the authors said so plainly. But the direction is consistent with the observational literature on tomato and carotenoid intake, and it is one of the first randomized trials to test the food directly in MASLD.

Here is what the number does not mean: it does not mean tomatoes replace the pattern. The control group also improved by 18 dB/m, which is the background effect of being in a study and eating normally. The tomato group improved more, and that difference is the signal the trial is pointing at.

The database reading: tomatoes already rate well

In the USDA-backed database on this site, raw tomatoes are rated Recommended. A typical entry shows about 18 kcal per 100g, 4.0g carbohydrate, 0.7g fiber, and essentially no fat - 0.1g total, none of it saturated. No added sugar, minimal processing, and a lycopene payload that increases with cooking. Tomato sauce, in its plain form, keeps most of that profile with the lycopene made more bioavailable by heat and oil.

The study's practical dose - a couple of medium tomatoes plus a half-cup of sauce a day - is easy to hit inside a Mediterranean pattern: tomatoes in a salad at lunch, sauce on whole grain pasta or in a vegetable soup at dinner. The database already lists tomatoes in the Recommended column with portion guidance; the POMOSANO trial adds a randomized, human-data reason to keep them there.

How our editorial team read this one

RCTs are our favorite kind of food news because they carry less interpretive fog than observational data. Still, we checked the trial's limits before covering it: 79 participants, six weeks, CAP as a surrogate rather than biopsy. Our data editor then ran the tomato entries through the rating pipeline to confirm the Recommended verdicts stand on independent grounds - saturated share near zero, no added sugar, fiber and water content - so the coverage did not hinge on a single small trial.

What we did not do is tell anyone that tomatoes are a liver medicine. They are a Recommended food with a new piece of supportive human data. The pattern - vegetables at the base of meals, tomatoes daily, saturated fat and sugar levers tight - is the same pattern this site has always encoded.

Fresh, cooked, or sauce: does form matter?

The trial used both fresh tomatoes and sauce, and the pairing is deliberate. Fresh tomatoes deliver lycopene in a water-and-fiber matrix; cooking with a little oil makes lycopene more bioavailable because it is fat-soluble. Eating both across a day hedges the bioavailability question without any food-science gymnastics. Canned tomatoes and plain tomato sauce, which the database treats as minimally processed whole foods, fit the same pattern; added-sugar pasta sauces do not, and the database flags those separately.

For the plate: tomatoes daily, in whatever form fits the meal - sliced on toast, diced into salads, simmered into a sauce, roasted with olive oil. The POMOSANO dose is small enough to be ordinary, which is exactly why the finding is useful.

Lycopene and the cooked-versus-raw question

Tomatoes are the single richest common source of lycopene, the carotenoid that gives them their red color. Lycopene is fat-soluble, which is why the bioavailability changes with preparation: cooking breaks down cell walls, and a little oil carries the compound into absorption. This is why the POMOSANO trial's design - both fresh tomato and sauce - makes biological sense. Fresh tomato contributes water, fiber, and potassium along with lycopene in its native matrix; the sauce delivers a more bioavailable form. Across a week, eating both covers the spectrum.

The database reflects the same logic in its form caveats. Raw tomatoes and plain tomato sauce rate Recommended, while added-sugar pasta sauces - a common hidden-sugar source - drift away from that verdict. The study's tomato dose is unambiguously the plain version, and the food-level translation is to read the label before reaching for the jar.

Where tomatoes sit in the broader pattern

A 35 dB/m CAP change is a real signal, but it is worth holding it in proportion. The POMOSANO participants were non-obese with mild-to-moderate disease, and the intervention was six weeks. The durable question for most people is not whether tomatoes help - it is whether the whole pattern holds. Tomatoes slot naturally into the Mediterranean framework the AASLD 2023 guidance recommends: a tomato-and-cucumber salad with olive oil at lunch, tomato sauce over whole grain pasta or in a minestrone at dinner, a few cherry tomatoes as a snack.

The database's Recommended column is where tomatoes live, and the portion guidance keeps the carbohydrate contribution in view. The trial adds a human-data reason to keep them there; the pattern is what sustains the change beyond six weeks.

Common Questions

Do tomatoes really reduce liver fat?

The POMOSANO RCT found 200g fresh tomatoes plus 50g sauce daily cut CAP by 35 dB/m over six weeks, about double the control group, independent of weight loss. It is a small short trial, but the direction matches the wider carotenoid literature.

How much tomato is the studied dose?

About 200 grams of fresh tomato (a couple of medium tomatoes) plus 50 grams of plain tomato sauce, daily. That fits easily into a Mediterranean pattern.

Is cooked tomato or sauce as good as fresh?

The trial used both. Cooking with a little oil makes lycopene more bioavailable; fresh tomato keeps the fiber. Eating both across the day is the practical approach. Added-sugar sauces are a different, Limit-adjacent food.

This is dietary reference information, not medical advice. Always consult your healthcare provider before making dietary changes.