Can a Tomato-Soy Drink Lower Inflammation in Adults With Obesity?

Possibly. In this small randomized crossover trial, 12 adults with obesity who drank a tomato-soy juice every day for four weeks had lower blood levels of three inflammation markers than before they started. Those drops were not significantly different from what happened on the control juice, so the signal is early.

Obesity often comes with what doctors call chronic low-grade inflammation. This is a slow, simmering kind of inflammation that you cannot feel, but that is linked to a higher risk of heart disease, diabetes, and other problems over time. Researchers wanted to know if a simple food-based drink could turn that simmer down. So they tested a juice made from tomatoes and soy, two foods rich in natural protective compounds.

How the drink works

Tomatoes are loaded with lycopene, the pigment that makes them red. Soy is rich in compounds called isoflavones. Both are thought to be key active compounds behind the health associations of these foods. The idea behind this study was that whole-food combinations might work better than isolated compounds. The juice supplied about 54 mg of lycopene and 190 mg of soy isoflavones a day.

What the data show

In this trial, adults with obesity drank two 6-ounce servings of the tomato-soy juice every day for four weeks. After a break period called a washout, they switched to a low-carotenoid control juice that lacked these protective compounds. Each person tried both drinks, so they served as their own comparison.

After the four weeks on the tomato-soy juice, blood levels of three inflammatory markers (IL-5, IL-12p70 and GM-CSF) were significantly lower than before the juice, and TNF-alpha trended down. However, these levels were not significantly different from those after the control juice; the authors think the study was too small to detect that difference. The urine changes after tomato-soy juice were mainly driven by soy isoflavone breakdown products, and both juices shared some urine changes, suggesting tomato itself has effects beyond lycopene.

Dr. Kumar’s Take

This study is practical. It is not a new drug or an expensive supplement; it is tomatoes and soy, foods most people can find at any grocery store.

The limits are real, though. Only 12 people finished, four weeks is a short window, and the drops were measured against each person’s starting point rather than clearly beating the control juice. Lower inflammation markers are a promising sign, not proof that this prevents heart attacks or diabetes down the road. A longer, larger study that tracks real health outcomes is needed. For now, this fits with what is already known about the value of a colorful, plant-rich diet.

Who might benefit most

The people in this study had obesity, with a body mass index between 30 and 45. That group often carries the kind of ongoing, low-grade inflammation this drink was tested against. If you fall into that category, a daily serving of tomato and soy is a low-risk addition to your routine, though it should support good medical care, not replace it.

Limits and caveats

This was a small, short trial, so the findings need to be confirmed in bigger groups over longer periods. The study measured inflammation markers and urine chemistry, not hard outcomes like heart attacks or hospital visits. It also tested a specific juice blend, so there is no guarantee that eating a tomato here or a bit of tofu there delivers the same steady effect. Soy can also be a concern for people with certain allergies, so check with your own doctor first.

Practical Takeaways

If you have obesity and want to lower low-grade inflammation, adding tomato-rich and soy-rich foods to your daily meals is a simple, low-risk place to start.
The participants in this study drank the juice every day for four weeks, not occasionally.
Treat this as a helpful addition to a healthy lifestyle, not a substitute for the medications, exercise, or weight management your doctor recommends.
If you have a soy allergy or take medications affected by diet, talk with your physician before making soy a daily habit.

FAQs

How much tomato-soy juice did people drink in the study?

Participants drank two 6-ounce servings each day, which adds up to about 12 ounces total. They kept this up for four weeks straight before switching to a comparison juice. That added up to about 54 mg of lycopene and 190 mg of soy isoflavones a day.

Is inflammation really a problem if I cannot feel it?

Chronic low-grade inflammation is the kind you usually cannot feel, which is exactly what makes it tricky. Unlike the swelling around a sprained ankle, this low-grade inflammation runs in the background for years. Over time it is linked to a higher risk of heart disease, type 2 diabetes, and other conditions, which is why lowering the blood markers tied to it is considered a meaningful step.

Can I just eat tomatoes and soy instead of drinking the juice?

The study specifically tested a concentrated juice blend, so there is no promise that eating an occasional tomato or a side of tofu gives you the same measured effect. Still, regularly including both foods in your diet is sensible and fits with broader nutrition advice. If you want to mirror the study closely, the key is a consistent daily intake of both lycopene-rich tomatoes and soy.

Bottom Line

In adults with obesity, drinking a lycopene- and soy-isoflavone-rich tomato-soy juice every day for four weeks lowered three markers of inflammation in the blood compared with before, and changed urine chemistry, mainly through soy breakdown products. The drops did not clearly beat the control juice, so it is an early sign that a simple, food-based drink could help calm the chronic inflammation that often comes with obesity. Larger and longer studies are still needed, but the takeaway is reassuringly familiar: colorful, plant-rich foods are good for you.

Read the full study