News that the World Health Organization (WHO) on Friday is expected to classify aspartame as a “possible carcinogen” has reignited a debate that has churned since the U.S. Food and Drug Administration (FDA) first approved the artificial sweetener more than four decades ago.
Aspartame, sold under the brand names NutraSweet, Equal and Sugar Twin, is widely used in diet sodas and in sugar-free and “reduced-sugar” food products, including ice cream, gum, yogurt and salad dressing. It is even found in such non-food products as mouthwash and cough medicine.
Tomorrow’s ruling — by the WHO’s quasi-independent cancer research arm, the International Agency for Research on Cancer (IARC) — means the IARC found only limited evidence linking aspartame to cancer in humans, based on its system of classifying potential hazards on a scale from “carcinogenic” to “probably not carcinogenic.”
While decades of industry-sponsored research found no hazards from aspartame, independent research has identified a broad range of harms, from liver and kidney damage to risks of seizure and premature birth.
Aspartame has been on IARC’s radar for over a decade. Only after a large-cohort observational French study found that a high intake of artificial sweeteners raised the risk of breast and obesity-related cancers did the WHO scientists deem it worth further investigation.
Earlier studies by the Ramazzini Institute found a correlation between aspartame levels — as little as what is recommended for daily intake by humans — and increases in malignant tumors in multiple organs in rats and mice.
The IARC classification does not establish safe consumption levels, but JECFA — the Joint Food and Agriculture Organization of the United Nations and WHO Expert Committee on Food Additives — also is reviewing aspartame and is expected to publish its “accepted daily limits” recommendations on Friday, coinciding with the IARC’s announcement, according to Reuters.
Regulators deem aspartame safe
Aspartame has been used in more than 6,000 products worldwide since the 1980s. The FDA approved it in 1981, deeming it safe in doses under 50 milligrams per kilogram of body weight.
The European Food Safety Authority (EFSA) conducted a full risk assessment in 2013, also finding aspartame safe for human consumption at 40 mg/kg or under. The EFSA recently said it has no reason to change that assessment based on current evidence.
“There’s been a huge number of studies performed on aspartame, which overwhelmingly show that it’s very safe, and has no carcinogenic potency,” Dr. Samuel Cohen, professor of oncology at the University of Nebraska Medical Center, told Reuters. Cohen has served on a number of expert panels and consulted for industry.
Erik Millstone and Elisabeth Dawson, in their paper analyzing all 154 studies reviewed by EFSA to make their 2013 determination on aspartame, found the agency “had consistently treated a very large majority of negative studies as reliable, while discounting each and every one of the studies providing evidence of harm as unreliable.”
The artificial sweetener industry has gone to great lengths to assure the public that “aspartame is safe.” It is concerned that the JEFCA review could “mislead consumers,” Reuters reported.
Decades of debate over safety
Since aspartame first entered the food supply, some scientists have warned about potential health effects, ranging from neurological symptoms to cancer.
In 1975, the FDA held up aspartame’s approval, finding fault with industry-led studies. A meta-analysis of 164 studies found that of “90 non-industry-sponsored studies, 83 identified one or more problems with aspartame.
“Of the 74 industry-sponsored studies, all 74 claimed that aspartame was safe,” wrote Ronnie Cummins and Katherine Paul in 2013, in an article published in Salon.
In 1995, the FDA “documented 92 aspartame-related symptoms, including migraines, memory loss, seizures, obesity, infertility, dizziness, fatigue, neurological problems and a host of others,” according to Cummins and Paul.
“Since 1981, when the product got formal approvals, there has been ongoing controversy,” Peter Lurie, president of the U.S.-based Center for Science in the Public Interest (CSPI), told Reuters. “We have been pushing for an IARC review for many years now.”
IARC’s ruling has far-reaching consequences, according to CSPI:
“IARC is a global authority on cancer-causing agents. It has classified the carcinogenicity of over 1,000 agents, including chemicals, biological agents, and other exposures. … The American Cancer Society and the California EPA both directly rely on IARC classifications to update their lists and warn the public about carcinogens.”
- Liver and lung cancer
- A rare type of urinary tract cancer
- Lymphoma and leukemia, including non-Hodgkin’s lymphoma
- Multiple myeloma
U.S. Right To Know, reporting on decades of science pointing to the serious health risks of aspartame, determined those risks include:
- Cardiovascular disease
- Alzheimer’s disease
- Stroke and dementia
- Intestinal dysbiosis
- Mood disorders
- Headaches and migraines
- Pre-term birth and overweight babies
- Early menarche
- Sperm damage
- Parkinson’s disease
In May, the WHO advised consumers against using non-sugar sweeteners (NSS) for weight control, naming aspartame, acesulfame K, saccharin and other products in their warning.
“There may be potential undesirable effects from long-term use of NSS, such as an increased risk of type 2 diabetes, cardiovascular diseases, and mortality in adults,” the WHO advisory stated.
The WHO guidelines provoked a furor of industry pushback, with industry arguing that aspartame “can be helpful for consumers wanting to reduce the amount of sugar in their diet.”
A number of studies take issue with this claim, some even concluding that use of the alternative sweeteners can induce weight gain.
What’s Donald Rumsfeld got to do with it?
If there were so many negative studies, how did aspartame get into our food supply? That is the question that Cummins and Paul posed in their Salon article.
Their answer: Donald Rumsfeld, former U.S. Secretary of Defense and former CEO of Searle, maker of aspartame. According to the article:
“In 1981, Rumsfeld, who had previously served as CEO of Searle, hand-picked Reagan’s new FDA commissioner, Arthur Hayes Hull, Jr. …
“On January 21, 1981, the day after Ronald Reagan’s inauguration, Searle re-applied to the FDA for approval to use aspartame as a sweetener in beverages. Hull, the brand new FDA commissioner, recommended by Rumsfeld, appointed a five-person Scientific Commission to review the board of inquiry’s prior decision. (A board of inquiry had been formed in 1975 when the FDA first questioned the validity of Searle’s studies on aspartame).
“When it became clear that the Scientific Commission was on track to uphold the 1975 ban by a 3-2 decision, Hull installed a sixth member on the commission. That led to a deadlocked vote. Hull then personally cast the tie-breaking vote. Voilà. Aspartame was approved.”
Not long after, Hull left the FDA to work for a PR firm whose clients included Searle and Monsanto. Monsanto later purchased Searle and spun off the company under the name NutraSweet.
For his trouble, Rumsfeld “earned a handsome $12 million bonus, presumably for his role in greasing the wheels for aspartame’s approval.”
Impact of IARC classification uncertain
Observers say they don’t expect any quick changes following Friday’s announcement.
“I don’t see how, without better-designed studies, we can make any conclusions on this [IARC ruling],” Andy Smith, professor with the MRC Toxicology Unit at the University of Cambridge, told Reuters.
IARC’s anticipated classification of aspartame will likely motivate more research designed to “help agencies, consumers and manufacturers draw firmer conclusions.”
“But it will also likely ignite debate once again over the IARC’s role, as well as the safety of sweeteners more generally,” Reuters reported.