A randomised clinical trial in Spain reports that middle‑aged adults who ate a daily portion of tomato paste for three months showed modest improvements on cognitive tests and subtle differences on brain scans.
What the trial did and found
Researchers led by nutritionist Ricardo López‑Solís investigated the effect of tomato consumption on cognition and brain connectivity. The intervention group consumed 35 grams of tomato paste each day for three months. The trial enrolled 42 healthy, middle‑aged adults for the cognitive assessments. A smaller subgroup of 14 participants underwent functional brain imaging.
- Cognitive outcomes: participants who ate the tomato paste showed enhanced selective attention and a small improvement in associative memory on neuropsychological tests.
- Imaging outcomes: scans in the subgroup suggested changes in functional connectivity across large‑scale brain networks, but the imaging analysis was underpowered and relied on a more lenient statistical threshold than originally planned.
"To our knowledge, this is the first clinical trial to link changes in the antioxidant lycopene with alterations in functional brain connectivity," the authors wrote in the journal Antioxidants.
Biological rationale
Tomatoes contain lycopene, a red pigment that acts as an antioxidant. Lycopene is able to cross the blood‑brain barrier — the selective membrane that keeps many blood substances from entering the brain — and has been proposed to reduce neuroinflammation, a process implicated in cognitive decline. The trial tests the hypothesis that dietary intake of bioactive tomato compounds could produce measurable functional changes in the adult brain.
Strengths and significant limitations
The study provides an early, experimentally controlled test of a plausible nutritional mechanism. However, several limitations mean the findings must be treated cautiously:
- The sample size was small: 42 for cognitive tests and only 14 for the imaging analysis, leaving the brain‑scan results underpowered.
- The trial was unblinded — both participants and researchers knew who received the tomato paste — which raises the possibility that expectations influenced effort or performance on the tests.
- The imaging results were reported using a less stringent statistical threshold than the study's planned correction method, increasing the chance that some reported effects may be false positives.
| Measure | Participants | Reported change |
|---|---|---|
| Cognitive testing | 42 | Improved selective attention; slight associative memory gain |
| Functional MRI | 14 | Tentative changes in network connectivity (underpowered) |
| Intervention | — | 35 g tomato paste daily for 3 months |
What this means for readers
The results are interesting but preliminary. They suggest that lycopene and other bioactive compounds in tomatoes may influence cognition and brain function, at least in the short term for healthy, middle‑aged adults. However, the study does not prove long‑term benefit, nor does it establish clinical recommendations. Larger, double‑blind trials with pre‑registered analysis plans are needed to confirm the effects and to rule out placebo or expectancy influences.
For now, the study adds to a body of research linking diet and brain health. Public health advice remains focused on balanced diets that include a variety of fruits and vegetables. Those interested in maximising cognitive health should consider well‑established measures such as regular physical activity, good sleep, vascular risk management (blood pressure, diabetes control), and a nutritious diet rich in plant foods rather than relying on a single food item.
The research was published in the journal Antioxidants and led by López‑Solís and colleagues at the University of Barcelona. As the authors note, the findings are a springboard for larger, more rigorous trials rather than a definitive conclusion.
