The pigment that gives the fruit its red colour, known as lycopene, has been shown to boost sperm quality, specifically around their size and swimming capabilities.
It means that a tablet that contains the pigment could hail the end of invasive and costly fertility treatment in the future.
Lycopene, although prevalent in tomatoes, is not absorbed well when the fruit is eaten, so it would need to be administered as a tablet.
In the 12-week experiment, 30 healthy volunteers took the pigment as a supplement in 14mg doses, whilst another 30 took placebos, with neither group knowing which tablet they had taken.
Researchers found that the those who had taken the supplement, called LactoLycopene, had almost 40% more fast-swimming sperm than when they began the trial, along with improvements to its size and shape.
Professor Allan Pacey, head of the University of Sheffield’s department of oncology and metabolism and lead author, said: “We didn’t really expect that at the end of the study there would be any difference in the sperm from men who took the tablet versus those who took the placebo.
“When we decoded the results, I nearly fell off my chair.
“The improvement in morphology – the size and shape of the sperm – was dramatic.”
He added that although the study did not look at overall sperm quality, he does believe the anti-oxidant properties of lycopene could be preventing sperm from becoming damaged.
The team say that the next stage is to repeat the exercise in men with fertility issues to see if the supplement can increase sperm quality and whether or not it can help couples conceive without invasive fertility treatments.
Sheena Lewis, a professor of reproductive medicine at Queen’s University Belfast, was cautious about the results of the study. “This is a small study where the volunteers were healthy, not infertile, with sperm parameters close to normal,” she said.
“Hence it is difficult to extrapolate any lycopene benefits to infertile men with poor semen quality. There are no clinical outcomes to the study.”