Here's What A Doctor Has To Say About Diet Coke And Cancer

I'm taking notes.
LAW Ho Ming via Getty Images

If you’re 1) terminally online and 2) a Diet Coke fan, I reckon you and I would get on. And I also suspect you’ve seen last week’s headlines about Diet Coke and its reported links to cancer.

The World Health Organisation’s cancer research sector, the International Agency for Research on Cancer (IARC), is set to publish a safety review on Diet Coke’s sweetener, aspartame, next month.

Reuters reported that in said review, “Aspartame, used in products from Coca-Cola diet sodas to Mars’ Extra chewing gum and some Snapple drinks, will be listed in July as ‘possibly carcinogenic to humans’ for the first time by the International Agency for Research on Cancer (IARC).“

Aside from leading some Diet Coke drinkers to question their choices, the news also caused some scientists and doctors to point out that these cancer warnings can have vastly different meanings and should cause very different levels of concern.

James Wong, a science writer, shared a Tweet which read: “According to the WHO aspartame is as carcinogenic as aloe vera and pickled veg. And less carcinogenic than eating red meat, drinking hot drinks, or being a hairdresser.”

“It’s rather like reporting an earthquake measuring 2 on the Richter scale hit a major city, without explaining that earthquakes of 2.5 or less are rarely felt, but can be measured on a seismograph,” he added.

And Dr. Karan Raj, a doctor known for debunking medical myths on TikTok, seems to agree. Here’s his take:


Aspartame is a carcinogen?

♬ original sound - Dr Karan Raj

Not all carcinogens are created equal

“The IARC uses four classifications,” Dr. Raj explains. Group 1 is carcinogenic – or cancer-causing – to humans; group 2A is “probably carcinogenic to humans”; group 2B is “possibly carcinogenic to humans”; and group 3 is “not classifiable.”

“These levels are based on the hazard of the substance itself,” Dr. Raj adds, and tells us nothing about the level of risk relative to the dosage.”

For instance, a kilo of aspartame might indeed have a different effect on your body to a kilo of flour – but we consume both of those differently, and in different quantities.

This is how, Dr. Raj says, “they(’ve) got plutonium in the same class one risk category as processed meat and being a hairdresser.”

He adds that the “possibly” (2B) category, into which aspartame seems set to fall, is used when there’s limited evidence of a carcinogenic effect in humans, or when the data comes from animal studies.

“For context,” he says, “other things included in group 2B include aloe vera, coconut oil, and pickled vegetables.“

He finishes by saying that “an epidemiological review of more than 12 studies looked at whether aspartame caused cancer in humans at the levels currently consumed.” (The “levels currently consumed” is a crucial difference between this study and that done by the IARC, because the latter didn’t account for dosage).

“The conclusion was clear,” he said. “Your Diet Coke is not gonna cause you cancer.”

I mean, it’s not like I needed much convincing anyway.