Daily Tomatoes Reduce Liver Fat in MASLD Trial

Daily consumption of raw tomatoes and tomato sauce significantly reduces controlled attenuation parameter (CAP)-defined hepatic steatosis in adults with metabolic dysfunction-associated steatotic liver disease (MASLD), according to an exploratory randomized controlled trial published in the journal Nutrients. Researchers found that a six-week tomato-rich diet outperformed a tomato-free control group, dropping median CAP values by 35 dB/m without requiring major weight loss or altering metabolic profiles.

Understanding the POMOSANO Study on MASLD and Tomato Intake

Metabolic dysfunction-associated steatotic liver disease stands as the most prevalent chronic liver disease globally. It links closely with obesity, insulin resistance, and cardiometabolic dysfunction. According to the study, hepatic fat accumulation alongside oxidative and inflammatory stress drives disease progression toward fibrosis, cirrhosis, and hepatocellular carcinoma. Current medical management relies heavily on lifestyle modification and dietary intervention, yet clinical guidelines largely emphasize overall weight reduction rather than specific food components.

To address this gap, investigators conducted the POMOSANO Study, a single-center Italian trial. The research team evaluated whether incorporating specific Mediterranean diet staples could directly influence liver fat. Investigators established eligibility criteria requiring participants aged 18 to 65 years with a confirmed MASLD diagnosis, hepatic steatosis, and at least one cardiometabolic risk factor. Individuals with excessive alcohol intake or alternative liver diseases were excluded.

Dietary Intervention Design and Patient Assessment

Researchers randomly assigned 79 participants to one of two groups: 37 individuals formed the control group on a tomato-free diet, while 42 participants entered the intervention group. According to trial parameters, the intervention group consumed 200 grams per day of raw tomatoes alongside 50 grams per day of tomato sauce for six weeks. All food items were sourced from a certified producer using standardized hydroponic cultivation to maintain consistency.

Clinical assessments occurred at baseline and following the six-week intervention. Measurements included weight, height, waist and neck circumferences, and body mass index (BMI), which was restricted to 30 kg/m² or lower for participants. Body composition evaluations utilized bioelectrical impedance analysis and dual-energy X-ray absorptiometry (DXA). Hepatic steatosis was confirmed using transient elastography to estimate fat accumulation via CAP thresholds of at least 275 dB/m.

Clinical Outcomes and Hepatic Steatosis Reductions

At baseline, both study cohorts showed comparable demographic characteristics, featuring a predominantly male distribution and low smoking prevalence. Throughout the six-week period, body weight, BMI, waist circumference, total body fat, and visceral adiposity remained stable with no significant divergence between the groups, according to the published data.

Despite the stable body weights, CAP values declined across both cohorts, with a notably greater decrease in the tomato intervention group. The median decline reached 35 dB/m among participants consuming tomatoes, compared to an 18 dB/m reduction in the control group. Statistical modeling established an adjusted difference in CAP change between the two groups of −26.63 dB/m (p = 0.003).

Mechanisms and Future Research Directions

Tomatoes contain high concentrations of carotenoids—particularly lycopene—alongside antioxidant and anti-inflammatory phytochemicals. Food processing methods dictate the bioavailability of these compounds, as lycopene absorbs more readily from cooked tomato products. Mechanistic evaluations indicate that these bioactives may modulate oxidative stress and hepatic lipid metabolism.

Because the trial relied on an exploratory design, a modest sample size, a short duration, and self-reported adherence, study authors emphasize that the findings remain hypothesis-generating. Future clinical investigations must confirm these observations in larger, longer-term randomized trials to determine if CAP reductions are sustained and clinically meaningful.

Frequently Asked Questions

What is MASLD?

Metabolic dysfunction-associated steatotic liver disease is a prevalent chronic liver condition characterized by hepatic fat accumulation linked to obesity and insulin resistance.

How much tomato did participants consume daily?

Participants in the intervention group consumed 200 grams of raw tomatoes and 50 grams of tomato sauce daily for six weeks.

Did participants lose weight during the study?

No, body weight, BMI, and total body fat remained largely stable throughout the six-week intervention period across both groups.

How was liver fat measured?

Researchers used the controlled attenuation parameter (CAP), an ultrasound-based transient elastography measure.