Eating tomatoes every day may reduce liver fat even when body weight stays the same, according to a new study. The finding came from a randomized controlled trial that followed 79 adults with metabolic dysfunction-associated steatotic liver disease (MASLD) over six weeks.
A research team at Italy's National Institute of Gastroenterology published the study, titled "Effect of Tomato Consumption on Liver Steatosis in MASLD (POMOSANO Study)," in volume 18, issue 15 of the international journal Nutrients in 2026. The team divided 79 patients with fatty liver and a BMI of 30 or below into two groups: one group of 42 ate one large fresh tomato and three to four tablespoons of tomato sauce daily, while the other group of 37 maintained their usual diet.
After six weeks, the controlled attenuation parameter (CAP), a measure of liver fat taken with the FibroScan ultrasound device, fell in both groups, but the size of the decline differed. The median CAP reduction in the tomato group was 35 dB/m, roughly double that of the group that did not eat tomatoes, which was 18 dB/m.
Notably, this difference appeared independently of changes in body weight or metabolic indicators. There were no significant differences between the two groups in body weight, BMI, body fat percentage or waist circumference, nor in blood sugar, cholesterol, liver enzymes or inflammation markers. This suggests that tomato consumption itself may have contributed to the reduction in liver fat through some other pathway.
The team pointed to antioxidant and anti-inflammatory compounds in tomatoes — such as lycopene, beta-carotene and polyphenols — as the mechanism. These substances likely lowered oxidative stress and acted on liver fat metabolism pathways such as SIRT1, AMPK, adiponectin and PPARα, the team explained. Providing both fresh tomatoes and sauce was also cited as a basis for the results. The reasoning is that cooking raises the absorption rate of lycopene, while fresh tomatoes retain heat-sensitive components, so combining the two forms increases the range of bioactive substances that can be consumed.
The team itself drew limits around the findings. It cited as limitations that the number of participants was only 79, that the study was conducted at a single institution for just six weeks, that participants knew which group they had been assigned to, and that blood lycopene concentrations were not measured separately. Liver fat was also assessed using an indirect ultrasound-based method rather than a biopsy. The team said that whether the CAP reduction is clinically meaningful and whether the effect lasts over time must be confirmed through longer-term studies with larger samples.
