Aspartame is found in the likes of diet coke. Photo / Getty Images
The WHO’s claims over the additive’s possible links to cancer are the latest in a bitter dispute that has gone on for almost 40 years.
It was a creation verging on the miraculous: a substance 200 times sweeter than sugar, with a fraction of the calories. But after 40 years of widespread global use, Aspartame – found in the likes of Diet Coke, low-fat yoghurt, low-calorie chewing gum, cough drops and breakfast cereal – is to be declared “possibly carcinogenic” by the World Health Organisation (WHO) within weeks.
A key ingredient in some 5,000 products worldwide, the news has come as a blow both to the £327 billion ($670 billion) diet-drink industry and the billions who now rely on cracking open a can of Diet Coke to get them through the afternoon.
While the International Agency for Research on Cancer (IARC; the cancer arm of the WHO) has yet to divulge how it reached its conclusion, the decision is in part thought to be linked to a large observational study in France, which last year found that elevated Aspartame and acesulfame K (another artificial sweetener) intake was associated with a higher risk of breast and obesity-related cancers.
Other research has linked it to mood disorders, leukaemia, cardiovascular disease, migraines, diabetes and a list of other ailments.
Still, the taste has proven too sweet for consumers to much mind those. First approved by the US Food and Drink Authority (FDA) in 1981, it is now present in 95 per cent of all carbonated diet drinks, with a market worth projected to hit £9.5 billion come 2027. All the while, fierce debate over its safety has raged on.
Those perturbed by the IARC’s declaration (to be made in conjunction with the Joint Food and Agriculture Organisation/WHO Expert Committee on Food Additives, or JECFA) are now asking one thing: if Aspartame was toxic, wouldn’t it have killed us already?
Cancer Research UK maintains that it is safe to consume, as do all regulatory bodies here and in the 90 other countries where it is used, leading Aspartame’s backers to dismiss the upcoming announcement as “dumb”, featuring “widely discredited research” that “contradicts decades of high-quality evidence”.
Aspartame turns to aspartic acid, phenylalanine and methanol in the body – with the latter breaking down into formaldehyde, a carcinogen. The current guidance from the European Food Safety Authority (EFSA) is that no more than 40mg per kilogram of body weight should be consumed daily (the FDA allows 50mg), but this would equate to swigging somewhere between 12-36 cans of the stuff each day (for an adult weighing roughly nine and a half stone) to cause harm.
“There is no conclusive proof yet that Aspartame is bad for you in the doses that we’re getting,” says Giles Yeo, professor of molecular neuroendocrinology at the University of Cambridge. “People ask: is Aspartame bad for you? And the question is, compared to what? Is it better to drink water than to drink something with aspartame? Of course it is.” The rest of the time, he says, the equation is less obvious – particularly if it helps people to cut out other, worse, alternatives.
The simplest way to put the debate to rest would surely be to look at the science. But this is where things grow significantly more complicated; Aspartame’s history is a decades-long battle between the lab coats and the beverage industry behemoths that have led it to be dubbed “one of the most contested [approvals] in the FDA’s history”.
The controversy began almost immediately, when producer G D Searle was accused of falsifying some of the data in studies submitted to the FDA for approval in 1974. It was initially granted – in spite of the research being called “poorly conceived, carelessly executed, or inaccurately analysed or reported” in an FDA task force report – but so was a petition for a public hearing the next year, following safety concerns.
By the end of 1975, Searle had been banned from marketing Aspartame, with a grand jury investigation ordered to determine whether two of their studies were falsified or incomplete.
Yet that investigation never went ahead, as the US lawyer due to conduct it instead took up a job at Searle’s law firm; in 1983, the FDA commissioner responsible for fully green-lighting Aspartame around a year earlier joined the company Searle used for public relations. Between 1977 and 1985, a period covering much of the approval process, Searle was led by Donald Rumsfeld, who would go on to become the US secretary of defence.
The close links between the industry’s major players and those enforcing the law have for decades fuelled theories that Aspartame’s approval was inevitable – and that no matter how many studies are produced, no government sees taking on these multi-billion dollar industries as worth their while.
Just as the health risks of cigarettes, asbestos, talcum powder and glyphosate (found in weed killer) were known ahead of time and covered up by those seeking to protect their interests, critics accuse Aspartame of following in their footsteps.
“Industry-sponsored research almost always produces the desired results,” says Marion Nestle, a molecular biologist at New York University and author of Soda Politics: Taking on Big Soda (and Winning).
She has been informally tracking studies funded by food and beverage groups – which in 2015, for instance, showed 156 of 168 backing the sponsor’s interests. An analysis of 166 medical journal articles published between 1980-85 found that all studies paid for by the industry confirmed Aspartame’s safety, while of 92 independently funded articles published during the same time period, 84 showed adverse health effects.
As well as their somewhat generous donations towards research, companies’ more subtle lobbying is a common feature. In 2014, Coca-Cola donated US$1.5 million to a now-disbanded nonprofit claiming to fund research into obesity, which promoted the idea that upping exercise levels was more important for health than what people consumed; the following year, they gave US$1 million to the University of Colorado School of Medicine to fund an advocacy group dismissing the links between fizzy drinks and obesity (the money was later returned).
Following a New York Times investigation, the company admitted that between 2010-15, it had spent US$132.8 million on scientific research and partnerships.
Nestle says these tactics are an integral part of “the playbook, which is what the cigarette industry used to cast doubt on evidence that smoking causes lung cancer – and all industries have picked it up”. Whether it’s cigarettes, talc or pop, she thinks the strategy is the same: “The first thing you do is cast doubt on the science… [saying] that the research isn’t strong enough. Then they’re going to attack the scientists who say otherwise, and say that they have agendas, or are not doing good science. And they’re going to lobby behind the scenes to make sure that no state or government [introduces] any regulation to try to get rid of this stuff.”
The billions of worldwide consumers serve as a useful tool for these companies too, she adds, as “there will be enough people who are devotees of diet soda, who will be insisting that these things not be taken away from them. Certainly, the soft drink industry is going to be able to use that.”
Don Barrett, a lawyer who took the tobacco industry to the courts – and cost them £158 billion (a tale recreated by Russell Crowe in the film Insider) – is a little more forgiving. After cigarette purveyors, he turned his attention to the food industry, fighting companies whose marketing claims about products being “natural” or “healthy” were no such thing – and says that while they have “tremendous power”, they are nowhere near as pernicious as the pharmaceutical or tobacco industries, who resort to “scorched earth tactics in litigation. But even the pharmaceutical industry is not as evil as the tobacco industry, from what I saw, and what I witnessed, and what I endured for 13 years when I was at the forefront of the fight against Big Tobacco.”
He agrees, though, that lambasting the science is the inevitable next step – a sentiment that will likely play more easily in the US, where the WHO’s handling of Covid remains a febrile topic. Doubt has already been cast over existing research, including the large-scale observational study in France that the IARC is thought to be basing their decision on, which was criticised for failing to show causal links between Aspartame consumption and raised cancer incidence.
Two studies produced by the Ramazzini Institute in Italy in 2006 and 2007 that reported Aspartame caused cancers in multiple sites in both mice and rats were also dismissed by critics, on account of too high a dose being administered. These tensions between either side have led the FDA to review its Aspartame guidance five times, and EFSA three – none of which has led to any changed decisions.
Those in Aspartame’s corner have compared this latest news to times the WHO has raised fears over the likes of red meat or using mobile phones; adding it to the “possibly carcinogenic” category (the third-most severe, of four) will rank it alongside some pesticides, petrol fumes and aloe vera.
“Aspartame is one of the most widely studied food ingredients and has repeatedly been determined to be safe by global scientific and regulatory authorities, which is why the Calorie Control Council is gravely concerned about any unsubstantiated assertions that contradict this conclusion,” according to Robert Rankin, its president.
“Consumers want context and that is what’s missing from these misleading claims.” The International Sweeteners Association added that the news coming ahead of the report’s release may create baseless fears over consuming Aspartame. “IARC is not a food safety body,” says its secretary general, Frances Hunt-Wood.
“No conclusions can be drawn until both reports are published.” That the FDA, EFSA and so many countries worldwide say Aspartame is still safe is considered the biggest – and perhaps only – seal of approval required. But this may be less a case of accuracy, and more “institutional inertia”, says Erik Millstone, professor of science policy at the University of Sussex, “because governments and committees are loath to admit they’ve ever made a mistake in the past.”
In a 2019 study, he examined issues within EFSA’s 2013 reapproval process, which led the panel to discount “the results of every single one of 73 studies that indicated that Aspartame could be harmful, while treating 84 per cent of studies providing no prima facie evidence of harm as unproblematically reliable”.
He believed too that changes to legislation post-Brexit might close the door on the sweetener for good, but is now hopeful that the IARC’s decision may encourage regulatory bodies to act, and finally curtail a product that “I don’t think should ever have been approved in the first place. And I think now, there is sufficient evidence to support a ban on its use.”
If Aspartame is found to have links to cancer, so will begin the expensive business of fighting claims through the courts. In 2015 the IARC classified glyphosate, found in weed killers, as “probably carcinogenic”– and years on, even as other bodies (including EFSA) have contested the decision, companies have still lost £8 billion in payouts awarding damages to customers.
In lieu of lengthy litigation, many believe that the Aspartame giants’ next step is to begin “reformulating like mad”, says Nestle. Still, it doesn’t always work, and getting it wrong costs. In 2015, Pepsico (which owns brands like Pepsi) announced that they were cutting aspartame from Diet Pepsi in a bid to stem falling sales, as “drinkers in the US told us they wanted Aspartame-free Diet Pepsi and we’re delivering… We recognise that consumer demand is evolving and we’re confident that cola lovers will enjoy the crisp, refreshing taste of this new product,” the company said. The next year, with sales down by more than double, the old recipe returned. Their blend of artificial sweeteners sucralose and acesulfame potassium was again introduced in 2020 – the result of aspartame controversy being “the number one thing customers are calling about”.
Packaging boasting of products being “Aspartame-free” are becoming increasingly common on American supermarket shelves, in spite of the fact they contain other artificial sweeteners. Sales figures after July 14′s ruling will show just how seriously the IARC’s verdict is taken, but it’s hard to see how the ruling will conclusively put the battle to bed. Aspartame’s backers are sure to decry it as bad science, while naysayers revel in the pendulum swinging back on their side.
Victory will be sweet for one side. At least, until the next round.
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