Artificial Sweeteners, Aspartame, And Cancer
Artificial Sweeteners, Aspartame, And Cancer
Explaining the confusing news about artificial sweeteners and your risk of cancer
The news about artificial sweeteners is incredibly confusing, and often scary. There was the recent story about sucralose being potentially genotoxic, and now the news that aspartame is possibly causing cancer. There’s nothing we love to hate more than a substance with the word ‘artificial’ in the name. The second something requires humans to actively process it somehow, it morphs from a wonderful natural product into a substance that is designed to make us all sick.
And then, just as we had all decided that artificial sweeteners were terrifying substances that were killing us all, the news breaks that actually aspartame is pretty safe. While the International Agency for Research on cancer, the IARC, has decreed that aspartame is a ‘possible’ carcinogen, another WHO body called the Joint Expert Committee on Food Additives (JECFA) has said that there is “limited evidence” for carcinogenicity and that reasonable levels of intake of aspartame are safe. Suddenly, the entire idea that artificial means bad for your health is in question. It’s a cycle that repeats itself with impressive regularity, because we are torn between a hatred for the manmade and a love of just how useful artificial things can be.
Take the recent noise about sucralose. Sucralose – the sweetener used in Splenda – is incredibly well-researched and generally considered to be fine. However, a recent study showed that when rats eat sucralose it can possibly break down into very small quantities of a substance called sucralose-6-acetate. This substance can, at very high concentrations, potentially cause some extremely minor negative impacts on cells in petri dishes.
If you read it like that, the research sounds fairly innocuous – it is very much lab-bench, early data, which in all likelihood has no bearing on human health. The amount of sucralose that you have to eat/drink to get the concentrations that were found to be harmful in these studies is tens of thousands of times more than a human being could reasonably expect to ingest. We’ve also got decades of safety data showing that sucralose isn’t consistently associated with negative health outcomes, and some decent – albeit industry-funded – evidence that such sweeteners are pretty safe.
Aspartame In The News
And then there’s aspartame. Technically, neither WHO agency has contradicted the other. The IARC has decided, based on very sparse data in humans and a few studies in rodents, that there is a very small risk that aspartame might increase the risk of a specific type of liver cancer. Meanwhile, JECFA has said that the risk increase for any human disease for aspartame is sufficiently low at the currently-advised level of consumption – which is set at 40mg/kg, or about 10 cans of Diet Coke a day – is safe. These two decisions don’t contradict, because the IARC is saying that it’s possible that, at a population level, there may be a tiny increase in cancer risk, while JECFA is saying that this risk increase is sufficiently unlikely that we probably don’t need to worry about it right now.
This is nuanced public health decision-making, and honestly it’s not entirely unreasonable. The IARC only look at a single question – does a substance cause cancer ever. In this case, the answer they’ve come up with is maybe, hence the 2B classification. Meanwhile JECFA looks at what regulatory agencies should actually implement, and in this case they believe that the risk to people is small enough that no further action needs to be taken.
The media saga that’s happened around these fairly boring, everyday reports, however, has been a sight to see. The initial Reuters article that broke the news that the IARC was considering aspartame to be a possible cancer risk went HUGELY viral across the globe. We’ve had weeks of coverage, and are probably now going to get weeks more.
This is all a perfect representation of our on-again, off-again attitude towards artificial sweeteners, and artificial things in general. We have this abiding fear that something which is produced by human beings must be bad for our health, even when those things are tested endlessly.
Take the issue of pharmaceutical products vs supplements – we care deeply whether drugs have a benefit in humans, and rightly so. Drugs are incredibly important, but can also cause a great deal of harm if they are ineffective, and we are reasonably suspicious of the pharmaceutical industry’s claims of benefit for their products.
But take that drug, call it a ‘natural’ supplement, and suddenly those rules no longer apply. If you call a chemical a drug, it’s carefully regulated, but if you call it a supplement there’s almost no oversight looking at whether it works, or even what the pills contain. Drugs are scary because they’re manmade, while supplements are fine because they’re natural, even though this makes no sense at all. To paraphrase the brilliant Australian comedian Tim Minchin, manmade things include lifesaving medicine and airplanes, while natural things include cow dung and snake venom.
Why I’ll Keep Drinking Diet Coke
But back to artificial sweeteners. We are also absolutely terrified that they might be bad for us in a way that vastly outweighs the evidence. We’ve been looking at aspartame and sucralose for decades, and have never identified any convincing, major health risks, but the yearly scare story comes around and suddenly it’s time to worry about them again.
None of this is to say that artificial sweeteners are irreplaceable or even entirely fine for your health. They can help a little bit with weight loss, probably, but the industry claims that they cannot possibly cause any harm to health aren’t quite accurate. It’s entirely possible - albeit a bit unlikely - that we’ll someday find an as-yet unidentified issue for one of these sweeteners that will make them unviable to use in our everyday lives.
But it’s also true that these chemicals are incredibly well-researched, commonly-used, and generally considered by independent regulatory agencies across the world to be safe. The IARC and JECFA decisions may seem confusing, but that’s just because they fundamentally aren’t aimed at you. This sort of monograph is set out to help public health agencies make decisions for entire countries, or judge whether something needs more research, not to help you or I in our day-to-day life.
You can see this quite easily when you put the research that goes into these decisions in context. As I noted, the IARC decision was mostly made on the basis of a potential increased risk from artificial sweeteners for liver cancer. But if you look at the research that underpins that decision, the risk increase is incredibly small. Of the people who drank absolutely no artificially sweetened drinks, about 3/100,000 got liver cancer each year. Of those who drank a can of Diet Coke a day, this risk increased to about 6/100,000, equivalent to a 0.003% increase in absolute terms. That’s so tiny as to be almost entirely meaningless at the individual level.
In general, the best health advice is to drink water if you’re going to drink anything. But there’s no evidence that artificial sweeteners such as aspartame and sucralose are particularly bad for your health.