Benzene is a carcinogenic molecule that may be formed in soft drinks when benzoic acid or benzoates react with ascorbic acid (Vitamin C). Benzoates are used as preservatives and ascorbic acid as an antioxidant.
In the body, benzene is metabolized to produce various molecules. These may linger in the body and interact with DNA and body tissues, leading to increased genetic mutations and other pro-cancerous effects. Benzene has been associated with immune suppression, certain cancers, and anemia.
While benzene levels in drinking water are monitored and limited, they are not regulated within soft drinks. Benzene is also a component of atmospheric pollution; casual soft drink consumption leads to significantly less benzene consumption compared to atmospheric levels but additive effects exist.
Soft drinks, cranberry juice
IARC Scientific Publications
U.S. Food and Drug Administration
Food Standards Agency