You’ve probably heard that soya consumption can affect your sperm count. In a study from Harvard University, it was found that men who had the highest daily intake of soya averaged 32 per cent less sperm per millilitre of ejaculate than those who didn’t consume the beans. In addition, two other studies found that a component in soya (daidzein) reduced testosterone levels and softened erections in rats. These findings definitely aren’t conclusive, though. “Most research about soya shows that it has positive effects on health, particularly on reducing the risk of heart disease and blood cholesterol levels,” says James.