Carrots boost male fertility, according to a new study by Harvard University School of Public Health. Studying the effects of fruits and vegetables on 'motility' (the ability of sperm to swim towards an egg), researchers discovered carrots have the greatest impact.

For the study, researchers asked nearly 200 young, college-age men in the Rochester, N.Y., area to follow diets including a variety of fruit and vegetables. Researchers tested the quantity and quality of their sperm before and after the dietary changes..

Researchers found that consuming yellow and orange-colored foods made sperm stronger. While sweet potato and melon enhanced the quantity and quality of sperm, carrots improved the sperm performance by between 6.5 and 8 per cent.

The sperm boosting properties of carrots was attributed to carotenoids, which the body converts into health-boosting antioxidants like Vitamin A that helps maintain healthy sperm and neutralise free radicals. Vitamin A can also be found in broccoli, sweet potatoes and oatmeal.

Researchers also said that Lutein, a carotenoid or antioxidant found in spinach and lettuce, had similar effects on sperm motility.

The report said: 'In a population of healthy young men, carotenoid intake was associated with higher sperm motility and, in the case of lycopene, better sperm morphology. Our data suggest that dietary carotenoids may have a positive impact on semen quality.'

On the other hand, red fruit and veggies, particularly tomatoes, increased the production of healthy sperm. Men who consumed these foods had fewer abnormally shaped sperm due to the presence of anti-cancer chemical lycopene. Tomatoes were found to add between 8 and 10 per cent more 'normal' sperm, which could help couples who have troubles conceiving.

The study, titled "Semen Quality in Relation to Antioxidant Intake in a Healthy Male Population," was published in the journal Fertility and Sterility.

Recent studies have indicated that average sperm count has decreased by more than half in western countries. Environmental toxins and physiological changes in the body, cell phones in pockets and estrogen in milk or water are speculated to be the primary cause for the drop in sperm performance, Medical Daily reports.