There is a lot of controversy in the scientific world as to whether or not high consumption of soda can have a carcinogenic effect on your body. For regular soda the main health risks associated are weight gain and higher risk for developing diabetes. One study showed women who consumed one or more cans of soda per day were at twice the risk for diabetes than women who consumed less than one can per month. No connections were found between regular soda and carcinogens.
Diet soda brings in all the controversy. Diet soda uses artificial sweeteners to lower the amount of calories in the soda while preserving the taste. Aspartame is one of the most commonly used artificial sweeteners. many claim that Aspartame is a carcinogen, yet the FDA says there is no real evidence to prove it. A study done by Morando Soffritti and colleagues performed an extensive study on the effects of Aspartame on rats. Their findings showed malignant tumors forming in rats having Aspartame administered to them daily. The FDA says these findings aren’t significant due to the fact that rats were the test subjects and not people. No solid findings have been concluded to prove diet soda can be a carcinogen.
Regular soda: No evidence of carcinogenic effects.
Diet soda: Animal studies show a possible connection to Aspartame as a carcinogen, but these findings have not been accepted as relevant to the human population.
References:
Soffritti M, Belpoggi F, Esposti D D, Lambertini L, Tibaldi E, Rigano A. First experimental demonstration of the multipotential carcinogenic effects of Aspartame administered in the feed to sprague-dawley rats. Environ. Health Persepc. 2006; 114(3): 379-385.
Vartanian L R, Schwartz M B, Brownell K D. Effects of soft drink consumption on nutrition and health: a systematic review and meta-analysis. Am J Public Health. 2007; 97(4): 667-675.
http://www.realclearsience.com/articles/2013/04/12/artificial_sweetener_aspartame_isnt_bad_for_you_106508.html