We all know that carrots can help your eyesight, but researchers have discovered that they can improve the fertility of men too. Studying the effects of fruits and vegetables on ‘motility’ (the ability of sperm to swim towards an egg), researchers at Harvard University have discovered that carrots have the greatest impact. (Journal of Fertility and Sterility 2013)
The study found that many yellow and orange coloured fruit and vegetables improved men’s fertility but carrots came out top of the list. The reason for this boost to sperm is attributed to pigments called carotenoids including beta-carotene, which the body converts into Vitamin A, an antioxidant. Antioxidants help to neutralise free radicals, destructive groups of atoms and a by-product of metabolism, which can damage cell membranes and our DNA.
Sweet potato and melon improved the quality and quantity of sperm but carrots increased sperm performance by 6.5%-8%. Red fruit and vegetables, particularly tomatoes which contain the anti-cancer chemical lycopene, were associated with fewer abnormal shaped sperm which can affect the chances of conceiving.
Psychological stress has been found to have a negative impact upon sperm quality, affecting its concentration, appearance and ability to fertilize an egg. Researchers from Columbia University’s Mailman School of Public Health (2014) have found that men who feel stressed are more likely to have lower concentrations of sperm in their ejaculate, and what sperm they do produce is often misshaped or have reduced motility, affecting its ability to swim.
Workplace stress was not a factor but it can affect reproductive health as job strain can reduce testosterone levels. They found that unemployed men had sperm of lower quality than men in employment, regardless of how stressed they were. It is believed that stress triggers the release of steroid hormones called glucocorticoids, which affect testosterone and sperm production.
Sperm experience a difficult journey as they navigate their way in the race to get to the egg and fertilize it. Not only do they have to swim in the right direction over distances that are about 1,000 times their own length, but are also exposed to different chemicals and currents along the way which is why so few actually reach the egg. Researchers from Massachusetts Institute of Technology (MIT) and Cambridge University (2014) have studied how sperm eventually arrive at the egg and have found that they are incredible swimmers, which is why some men whose sperm are not great swimmers have fertility problems.
They discovered that the sperm are able to swim extremely efficiently upstream in certain currents and surprisingly, sperm do not swim in a straight line, but in a spiralling motion along the walls of the channel. The sperm cells react to the difference in the speed of currents near the walls of the chamber, where the fluid is attracted to the surface and are therefore at its slowest as compared to the free flowing centre of the tube.
Research in the Ecologist found that sperm motility is slower when you use some sexual lubricants so choosing a sperm friendly lubricant is advisable.
Going commando for better sexual health and to improve the quality of your sperm is often recommended and thinking about the type of underwear and the material it is made from too.
Sperm counts across the Western world are declining due to poor lifestyles including diet, lack of exercise, alcohol consumption, smoking and stress but by including dietary carotenoids in the diet and using research about the way in which sperm travel to get to the egg by designing new diagnostic tools and more efficient artificial insemination procedures, men could be helped to boost the quality and quantity of their sperm to improve their chances of becoming a father.