The side effects of Mountain Dew include diabetes, obesity, bad teeth, high blood pressure and other health problems if people drink it in large quantities. These health problems are directly related to the high amounts of sugar and caffeine that Mountain Dew contains. Side effects of Mountain Dew are similar to those of any other soda.
Consumers are often worried about the side effects of Mountain Dew and other yellow sodas because of an urban myth that drinking them lowers a man's sperm count. In fact, many people admit they believe in this myth so much that they use Mountain Dew as a form of contraceptive. These believers think that the Yellow Dye No. 5 used in the making of Mountain Dew and other yellow soft drinks has spermicidal properties. They also point to Mountain Dew's extremely high caffeine content.
According to the Federal Drug Administration, Yellow Dye No. 5 does not pose any kind of threat to sperm. Also, the FDA says that caffeine may improve the mobility of sperm rather than kill it. This means that drinking large qualities of Mountain Dew may increase the efficacy of sperm. Mountain Dew has around 55 milligrams of caffeine per can, while a Coca-Cola has only 37.2 milligrams.