UK researchers tested the tomato pill that contains lycopene, a natural antioxidant that also gives tomatoes their colour, versus a dummy drug in 72 adults and found it improved the functioning of blood vessels.
A spin-off company from the University of Cambridge - Cambridge Theranostics (CTL) - has come up with its own "tomato pill".
Working independently of CTL, a team at Cambridge University set out to see if the pill would have the desired effect.
They recruited 36 volunteers known to have heart disease and 36 "healthy" controls, who were all given a daily tablet to take, which was either the tomato pill or a placebo.
To ensure a fairer trial, neither the volunteers nor the researchers were told what the tablets actually contained until after the two-month study had ended and the results were in, 'BBC News' reported.
For comparison, the researchers measured something called forearm blood flow, which is predictive of future cardiovascular risk because narrowed blood vessels can lead to heart attack and stroke.
In the heart disease patients, the tomato pill improved forearm blood flow significantly, while the placebo did not.
The supplement had no effect on blood pressure, arterial stiffness or levels of fats in the blood, however.
Lead researcher Dr Joseph Cheriyan said the findings were promising, but added: "A daily 'tomato pill' is not a substitute for other treatments, but may provide added benefits when taken alongside other medication.
"However, we cannot answer if this may reduce heart disease - this would need much larger trials to investigate outcomes more carefully," Cheriyan said.