Tomatoes are among the most widely eaten foods on the planet, and a new clinical trial out of Spain has tested whether a daily dose of tomato paste does anything measurable to the brain. Over three months, 42 healthy adults alternated between a lycopene-rich diet built around tomato paste and a low-lycopene diet, taking cognitive tests and, for a smaller group, brain scans along the way. The differences the researchers found were real in a statistical sense but modest in size, and the team is careful to frame the work as an early signal rather than proof that eating more tomatoes changes how anyone’s brain functions.
A crossover design pits tomato paste against a low-lycopene diet
The trial used a crossover structure, meaning each of the 42 middle-aged participants effectively served as their own control. Before the study began, volunteers spent a week avoiding lycopene-rich foods such as tomato, watermelon, papaya, grapefruit and guava to establish a baseline. They then completed two three-month phases in randomized order: one involving 35 grams of tomato paste eaten daily, the other a diet kept deliberately low in lycopene. A one-month washout separated the phases, with three weeks of normal eating followed by a week back on the low-lycopene pattern to reset before the next leg. The work was led by nutritionist Ricardo López-Solís of the University of Barcelona, with researchers from Spain’s CIBEROBN biomedical obesity and nutrition network also involved. “To our knowledge, this is the first clinical trial to link changes in the antioxidant lycopene with alterations in functional brain connectivity,” the study authors wrote, framing the work as an early step rather than a settled finding.
Cognitive tests picked up gains in attention and a smaller memory effect
After the tomato-paste phase, participants showed improvements on tests of selective attention, with concentration scores up by 7.2 points and processing speed up by 8.3 points compared with the low-lycopene phase. A test of associative memory, based on matching faces to names, improved by a smaller 0.8 points. Those numbers describe within-group changes on standardized cognitive tests, not a dramatic before-and-after transformation, and the researchers note an important limitation: the trial was unblinded, so both participants and researchers knew which diet phase was underway at any given time. That leaves open the possibility that expectations or motivation, rather than lycopene itself, nudged performance on the tests.
Brain scans in a 14-person subgroup hinted at network changes
A smaller subset of 14 participants underwent functional MRI scans during each phase. These scans showed reduced resting-state connectivity in the right frontoparietal network and in an auditory network during the high-lycopene phase, and reduced connectivity in a dorsal attention network during the low-tomato phase. The imaging analysis relied on an uncorrected statistical threshold that was more lenient than the correction method the researchers had originally planned to use, and the authors themselves describe this portion of the study as small and statistically underpowered. The researchers interpret the pattern as consistent with “functional reorganization” of large-scale brain networks, comparing it to changes seen after training programs designed to improve working memory, according to the full study published in the journal Antioxidants.
Lycopene and a brain-growth protein moved together with the diet
Blood tests taken after each phase showed lycopene concentrations rose markedly during the tomato-paste period, alongside a borderline increase in brain-derived neurotrophic factor, a protein involved in neuron growth and synaptic adaptability. The authors describe the parallel shifts in lycopene, this growth factor, and network connectivity as suggestive of a broader reorganization tied to tomato intake, but they stop short of establishing a causal chain running from lycopene to brain-network change to the cognitive test scores. Lycopene is an antioxidant capable of crossing the blood-brain barrier, which is part of why researchers have been curious about its neurological effects, though tomatoes also contain a mix of other antioxidants and vitamins that could plausibly contribute.
Earlier tomato-and-cognition trials point in a similar, imperfect direction
This is not the first attempt to connect tomato compounds with brain performance. An eight-week pilot study in older adults that used a carotenoid-rich tomato-powder supplement previously found improvements in processing speed, attention and working memory compared with a placebo. A separate five-week crossover trial testing a mixed-berry beverage containing tomato powder improved working memory in older adults but not selective attention, a discrepancy the study authors suggested might reflect practice effects from taking the same cognitive test repeatedly. Broader observational research in mice and humans has also linked higher lycopene levels to lower rates of prostate and lung cancer as well as heart and liver disease, though none of that evidence establishes cause and effect either.
Small numbers and an unblinded design limit how far the findings travel
With 42 total participants and only 14 scanned, the trial is too small to support firm conclusions about tomato paste and brain function in the general population. The unblinded design compounds that caution, since neither the cognitive-test results nor the brain scans can fully rule out the influence of participants knowing which diet they were following. The researchers say larger, longer-term trials are needed to determine whether the neural changes they observed persist over time or translate into effects that would matter in everyday life. In the meantime, cooking tomatoes into products like paste is already known to break down plant cell walls in ways that can make lycopene easier for the body to absorb than from raw tomatoes, so the nutrient of interest is not lost in processing even if its brain effects remain unproven.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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