Soda is widely thought to negatively affect men’s sexual health, although experts disagree about why. According to a study conducted at Copenhagen University Hospital, men who regularly consume a liter or more of soda per day have a sperm count that is reduced by as much as 30 percent compared to men that abstain from soda. Some experts believe it is the caffeine in soft drinks that lowers sperm counts. Others maintain that the sugar in soda reduces sperm count and leads to obesity, which impairs vitality and performance. A study published in the medical journal Fertility and Sterility suggests that the bisphenol A chemical commonly found in plastic soda bottles and soda cans is responsible for lowering sperm count and sperm quality.