Aspartame Safety Cemented by Major US Study

06/04/06 A major new epidemiology study from the United States National Cancer Institute confirms previous study conclusions that there is no link between aspartame consumption and leukemias, lymphomas and brain tumors. The study, presented at the American Association of Cancer Research meeting in Washington, D.C. evaluated over 500,000 men and women between the ages of 50 and 69 over a five-year period. The researchers found that there was no evidence of an increased risk of leukemias, lymphomas and brain tumours among people who use aspartame.  The researchers report, “Our findings from this epidemiologic study suggest that consumption of aspartame-containing beverages does not raise the risk of hematopoietic or brain malignancies.”

Researchers examined aspartame-containing beverage consumption in relation to incident hematopoietic and brain cancers among 340,045 men and 226,945 women aged 50-69 years in the NIH-AARP Diet and Health Study. The self-administered baseline food frequency questionnaire queried regarding consumption frequency and “diet” type preference of three potentially aspartame-containing beverages (soda, fruit drinks, and iced tea) as well as aspartame added to coffee and hot tea. From the responses, the researchers computed daily consumption of aspartame, taking into account aspartame content, portion size, and intake frequency of each beverage. Relative risks (RR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards regression that adjusted for age, sex, ethnicity, body mass index (BMI: weight in kilograms/height in meters squared; 4 categories of ≥18.5 and <25, ≥25 and <30, ≥30 and <35, and ≥35), and history of diabetes and smoking.

During up to 5 years of follow-up (1995-2000), histologically-confirmed hematopoietic cancers (N = 2,106) and brain cancers (N = 376) were ascertained by linkage with state cancer registry of eight study areas. Compared with no consumption of aspartame-containing beverages, increasing levels of consumption were not associated with any risk of overall hematopoietic cancer (adjusted RR for ≥ 600mg/day vs. none = 0.93, 95% CI = 0.72, 1.19, P trend = 0.75) or brain cancer (RR for ≥ 400mg/day vs. none = 0.74, 95% CI = 0.49, 1.13, P trend = 0.03), in men or women. The association remained null for main subtypes of lymphoid cancers (Hodgkin lymphoma, non-Hodgkin lymphoma, and multiple myeloma) and the non-Hodgkin lymphoma subtypes (small lymphocytic lymphoma and chronic lymphocytic leukemia, immunoblastic lymphoma and lymphoblastic lymphoma/leukemia) and non-lymphoid leukemias reported in the previous animal study. These findings did not change materially with further adjustments for education, family history of cancer, physical activity, alcohol, caffeine, and other dietary and lifestyle risk factors. Our findings from this epidemiologic study suggest that consumption of aspartame-containing beverages does not raise the risk of hematopoietic or brain malignancies.

The study confirms the findings of a recent 2005 report, Review of Lymphatic and Hematopoietic Cancer Incidence Trends & Consumption of Aspartame, in which researchers concluded, upon examining cancer trends from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program that there is no consistent pattern (of leukemias or lymphomas) that parallels the rise in aspartame consumption. Further, the findings also support those of three recent animal studies conducted by the National Toxicology Program (NTP) designed to evaluate whether aspartame is capable of causing cancer.  These U.S. government-funded and-managed studies were conducted using Good Laboratory Practices (GLP). The results of these cancer studies, in which aspartame was fed to mice bred to be especially sensitive to cancer-causing agents, unequivocally indicated that "there was no evidence of carcinogenic activity [cancer] of aspartame."

The Center for Science in the Public Interest had pressed the government in the US to further assess aspartame’s safety after an Italian study last year showed that female rats fed aspartame developed more leukemias and lymphomas than rats that were not fed the sweetener. Dr. Robert Bursey, President, Ajinomoto Corporate Services, LLC, the largest producer of aspartame, said of the findings, "While we have always been confident in the safety of aspartame, this study overwhelmingly reinforces that conclusion and should put to rest any speculation to the contrary.”

Last week it emerged that Holland Sweetener Company the 50/50 joint venture between Royal DSM N.V. (the Netherlands) and Tosoh Corporation (Japan) would withdraw from the aspartame business, including Twinsweet. DSM reported that HSC will terminate its activities at the end of 2006 and as a consequence will discontinue the production of aspartame in the fourth quarter of 2006.