The Cancer Scare of the Month for November was a classic that first appeared on the charts in the '70s: aspartame, a.k.a. Nutrasweet. Back then, one study found that rats who were fed huge doses of the artificial sweetener developed more brain tumors than a control group. The results were never replicated, and extensive research indicated that aspartame, which the body breaks down into components that are present in many foods, is safe at the levels anyone could reasonably be expected to consume. In 1981 the Food and Drug Administration approved the use of aspartame in dry foods; aspartame-sweetened soda got the nod in 1983.
Now Dr. John Olney, a Washington University neuropathologist and longtime opponent of aspartame, is citing a 10 percent increase in the U.S. brain cancer rate between 1984 and 1985 as evidence that the FDA made a mistake. "Compared to other environmental factors, aspartame appears to be a promising candidate for explaining the surge in brain tumors in the mid-1980s," he and three colleagues wrote in the November Journal of Neuropathology and Experimental Neurology. "Although our analysis does not establish definitive proof of a causal link…it does indicate the need for a reassessment of the carcinogenic potential of this agent."
Predictably, the study led to alarming headlines and sweeps-week TV news stories, calls from consumer groups for more research, and warnings to keep aspartame away from children.
But as FDA officials and other critics of the study soon demonstrated, the cloud consists mainly of hot air. The critics noted that the incidence of brain cancer began rising in 1973, years before aspartame was approved, and the increase was due almost entirely to cases in people over 65, who are not major consumers of the sweetener. The trend leveled off after 1985, even while aspartame consumption was rising, and the rate actually dropped slightly from 1991 to 1993. Harvard epidemiologist Dimitrios Trichopoulos called Olney's argument "misleading" and "preposterous," noting that it hinges on "two biologically indefensible assumptions: that a certain factor (aspartame) could cause a solid tumor (brain cancer) with a latency period of less than four years and that subsequent widespread exposure to the factor would cause no further increase in the incidence of that cancer."