By Ruth Kava, Ph.D., R.D., Aubrey Noelle Stimola, Rivka Weiser, Lynnea Mills
Posted: Monday, December 13, 2004

REPORT
Publication Date: December 13, 2004

Introduction
Pediatric Vaccines and Autism    
PCBs in Salmon and Cancer   
Cell Phones Cause Brain Tumors    
Nightlights and Leukemia     
Chemicals in Cosmetics     
Mercury in Seafood Causes Neurological Problems in Humans  
Cheeseburgers and Cardiovascular Disease (CVD)  
Antibiotics Cause Breast Cancer    
Teflon Causes Health Problems in Humans   
Soda Causes Esophageal Cancer    
Dishonorable Mention     
Deodorants, Antiperspirants Cause Breast Cancer 
Plastics Cause Cancer

The Scare:
While soda is a frequent target of some activist groups who term it “junk food,” media coverage in May 2004 took the vilification of the product to new heights (or perhaps, more accurately, a new low). Soda was reported to be a cause of esophageal cancer, a relatively uncommon but usually fatal cancer diagnosed in about 14,250 people per year in the United States.(120) Currently-known risk factors for esophageal cancer include tobacco use and alcohol use, particularly in combination.

Where Did the Scare Come From?
A team of scientists from India reported that the rise in per capita consumption of soda was correlated with the increased rate of esophageal cancer in the United States (both increased more than 400% between 1946 and 2000). Rates of esophageal cancer in countries with per capita consumption of more than 20 gallons of soda per year had also increased. The researchers presented the findings in May 2004 at the Digestive Disease Week conference in New Orleans, meaning that the research had not been subject to peer review (papers published in high-quality scientific journals are rigorously reviewed).

The Media Coverage:
Some reports made the classic mistake of interpreting the evidence of correlation as indicating that soda was shown to cause esophageal cancer. The headline of a Reuters article (which was also picked up by other media) announced “Sodas Raise Cancer Risk, U.S. Study Finds,”(121,122) and a CNBC reporter warned, “those fizzy drinks many of us love might pose a serious health risk.”(123) The Times-Picayune (New Orleans) said that the study “concluded carbonated drinks increase the risks of cancer of the esophagus” and that “researchers said they have linked the two together as cause and result, but they cannot establish beverage consumption as the only link.”(124) That paper did, however, later publish a correction clarifying that only a correlation was found.

The Bottom Line:
Indeed, the fact that both soda consumption and esophageal cancer have become more prevalent since 1946 was the only evidence presented in support of a “link” between the two. The researchers did hypothesize about a biological mechanism by which soda could irritate the digestive tract and cause esophageal cancer, but the research itself certainly did not demonstrate this causal link or ascertain that those who developed esophageal cancer ever drank soda. The rise in esophageal cancer rates could undoubtedly be similarly correlated with a laundry-list of other things that have also increased since 1946, including watching television, increase of women in the workforce, use of computers, and more. As this “study” basically did not have any scientific findings about cancer risk—simply showing that both soda consumption and esophageal cancer rates had risen significantly—it is remarkable that the mainstream media even reported it at all.

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