Artificial sweeteners and cancer risk in a network of case-control studies

Background: The role of sweeteners on cancer risk has been widely debated over the last few decades. To provide additional information on saccharin and other sweeteners (mainly aspartame), we considered data from a large network of case-control studies. Methods: An integrated network of case-control studies has been conducted between 1991 and 2004 in Italy. Cases were 598 patients with incident, histologically confirmed cancers of the oral cavity and pharynx, 304 of the oesophagus, 1225 of the colon, 728 of the rectum, 460 of the larynx, 2569 of the breast, 1031 of the ovary, 1294 of the prostate and 767 of the kidney (renal cell carcinoma). Controls were 7028 patients (3301 men and 3727 women) admitted to the same hospitals as cases for acute, non-neoplastic disorders. Odds ratios (ORs), and the corresponding 95% confidence intervals (CIs), were derived by unconditional logistic regression models. Results: The ORs for consumption of saccharin were 0.83 (95% CI 0.30-2.29) for cancers of the oral cavity and pharynx, 1.58 (95% CI 0.59-4.25) for oesophageal, 0.95 (95% CI 0.67-1.35) for colon, 0.93 (95% CI 0.60-1.45) for rectal, 1.55 (95% CI 0.76-3.16) for laryngeal, 1.01 (95% CI 0.77-1.33) for breast, 0.46 (95% CI 0.29-0.74) for ovarian, 0.91 (95% CI 0.59-1.40) for prostate and 0.79 (95% CI 0.49-1.28) for kidney cancer. The ORs for consumption of other sweeteners, mainly aspartame, were 0.77 (95% CI 0.39-1.53) for cancers of the oral cavity and pharynx, 0.77 (95% CI 0.34-1.75) for oesophageal, 0.90 (95% CI 0.70-1.16) for colon, 0.71 (95% CI 0.50-1.02) for rectal, 1.62 (95% CI 0.84-3.14) for laryngeal, 0.80 (95% CI 0.65-0.97) for breast, 0.75 (95% CI 0.56-1.00) for ovarian, 1.23 (95% CI 0.86-1.76) for prostate and 1.03 (95% CI 0.73-1.46) for kidney cancer. A significant inverse trend in risk for increasing categories of total sweeteners was found for breast and ovarian cancer, and a direct one for laryngeal cancer. Conclusion: The present work indicates a lack of association between saccharin, aspartame and other sweeteners and the risk of several common neoplasms.