By Morgan Nwanguma
A specially formulated tomato-soy juice rich in lycopene and soy isoflavones significantly reduced markers of inflammation in adults with obesity after just four weeks, according to a new clinical study.
Researchers found that healthy adults with obesity who consumed the beverage daily experienced notable declines in several key inflammatory proteins in their blood. In contrast, participants who drank a control tomato juice lacking these bioactive compounds did not see the same benefits.
The findings suggest that the tomato-soy juice could serve as a functional food to help manage chronic inflammation, a condition closely linked to obesity and a wide range of long-term health problems.
The beverage contains high concentrations of lycopene, a powerful antioxidant found in tomatoes, and soy isoflavones, naturally occurring plant compounds that have been associated with various health benefits.
Compared with the control group, participants who consumed the enriched juice showed significant reductions in three proteins associated with systemic inflammation, highlighting the potential of targeted dietary interventions to support metabolic health.
“The idea is, can we use food-based interventions to modulate inflammation?” said lead author Jessica Cooperstone, associate professor of horticulture and crop science at The Ohio State University. “And can we test this in a rigorous way so that we can really see this is affecting inflammation, versus just saying something is anti-inflammatory?”
Building on these findings and earlier research, Cooperstone and her colleagues have received funding from the National Institute of Diabetes and Digestive and Kidney Diseases to launch a pilot clinical trial exploring whether the same tomato-soy juice can help reduce inflammation in people with pancreatitis.
The study findings were recently published in the journal Molecular Nutrition & Food Research.
Why Tomatoes and Soy?
Lycopene, the compound responsible for the red colour of tomatoes and several other fruits and vegetables, belongs to a class of plant pigments known as carotenoids. Soy isoflavones are naturally occurring flavonoids that can mimic certain effects of the hormone oestrogen. Both compounds are phytochemicals that play important roles in plant function and have been linked to potential health benefits in humans.
The tomato-soy juice used in the study was developed several years ago by researchers at Ohio State University after earlier evidence suggested that diets rich in tomatoes and soy might lower the risk of prostate cancer. The beverage was made from specially bred tomatoes with elevated lycopene levels and fortified with soy isoflavone extract.
Subsequent studies at Ohio State found that increased consumption of the juice was associated with lower levels of prostate-specific antigen in some men with prostate cancer. Additional research has also suggested that tomatoes and soy – either individually or in combination, may influence inflammatory and metabolic pathways involved in obesity and other chronic diseases.
“There’s been enough compelling evidence that compounds from tomatoes and soy might be modulating inflammation that we decided to test this in people,” Cooperstone said.
Human Trial Shows Lowered Inflammation
12 healthy obese adults were used in the study. Participants consumed two 6-ounce cans of the tomato-soy juice every day for four weeks. After a washout interlude, they drank a low-carotenoid tomato juice for another one month.
“The hypothesis is that it’s the lycopene from the tomatoes and the isoflavones from the soy that’s inducing the effect, so we didn’t want to have a control that’s just water,” Cooperstone said.
Scientists took blood samples from participants before and after each four-week intervention period to measure cytokines, inflammatory proteins produced by the immune system.
The results showed that only the tomato-soy juice led to significant reductions in three key cytokines: interleukin (IL)-5, IL-12p70, and granulocyte-macrophage colony-stimulating factor (GM-CSF). The researchers also observed a decline in tumour necrosis factor-alpha (TNF-α), although the reduction did not reach statistical significance.
Changes Extended Beyond Inflammatory Markers
The research team also analysed urine samples collected before and after each study phase to identify changes in metabolites – the molecules generated as the body processes nutrients and carries out essential biological functions.
Some metabolic changes were detected following consumption of both the tomato-soy juice and the control tomato juice, suggesting that tomatoes themselves may exert biological effects even in the absence of elevated lycopene levels.
However, shifts in metabolites linked to soy isoflavones were more pronounced among participants who consumed the tomato-soy juice. Although further research is needed, these findings provide additional evidence that the beverage produces measurable biological effects in the body.
“This is probably a function of the fact that there’s more to our intervention agents than just these two compounds,” Cooperstone said. “Ultimately, we want to have a better understanding of how the foods that we eat are relating to our health. And when we really want to be sure, we need to test them in clinical trials. And that’s what we’re doing here.”
Potential Benefits for People with Pancreatitis
The research team has also generated evidence from animal studies indicating that the tomato-soy juice may help reduce inflammation and lessen the severity of chronic pancreatitis. These findings provided the scientific basis for launching a new clinical trial involving patients with pancreatitis. Researchers hope the beverage could offer a promising dietary approach for managing a condition that currently has few effective treatment options.
“Care for patients with pancreatitis is palliative, focused on controlling pain and GI symptoms. Our hypothesis is that the tomato-soy juice may serve as an intervention to decrease inflammation and hopefully increase patients’ quality of life,” Cooperstone said.
The project had the backing of the U.S. Department of Agriculture, the National Institutes of Health, the Lisa and Dan Wampler Endowed Fellowship for Foods and Health Research, as well as the Foods for Health Initiative at Ohio State.
Other members of the team aside the first author – Maria Sholola consist of Jenna Miller, Emma Bilbrey, David Francis and Thomas Mace of Ohio State, along with Janet Navotny of the USDA. Mace serves as the lead principal investigator of the pancreatitis trial. Cooperstone, Philip Hart and Kristen Roberts of Ohio State are also principal investigators involved in the research.
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