Will Diet Coke now carry a cancer warning? Everything you need to know after bombshell WHO ruling

Aspartame will be declared a potential cancer risk to humans, a bombshell report claimed today.

The artificial sweetener, used in a multitude of soft drinks including Diet Coke and Dr Pepper, will be listed as ‘possibly carcinogenic to humans’ in a World Health Organization reclassification within the next few weeks, insiders said.

But what is aspartame? What other products is it found in? And how much is safe to consume?

Here, MailOnline answers all your questions. 

What is aspartame?

Aspartame is an artificial sweetener first developed in the 1960s — completely by accident — and brought into market about 20 years later.

It is approximately 200 times sweeter than sugar. 

This means less is needed gram per gram than sugar to achieve the same sweet result, meaning products that contain it tend to be less calorific.

Unlike sugar, it does not raise blood sugar levels, making it a handy alternative for diabetics.

Chemically, aspartame is made up of three substances — aspartic acid (40 per cent), phenylalanine (50 per cent) and methanol (10 per cent).

What is it found in?

Aspartame is added to hundreds of products which market themselves as being ‘diet’ or ‘sugar-free’. 

The most famous examples are Diet Coke and Dr Pepper, as well as sugar-free gums like Extra’s.

Other examples include low fat or diet yogurts and jellies.

Is there aspartame in Coke Zero and Pepsi Max too?

Both products list aspartame in their ingredients list.

Other soft drink brands like Fanta, Lucozade and Sprite as well as some brands of squash and juice, like Robinsons and Ribena, also contain the artificial sweetener.

This means that it’s not just stereotypically ‘diet’ or ‘light’ soda drinks that contain the sweetener and many people could be consuming them without realising. 

What are its dangers?

Aspartame consumption has been anecdotally linked to headaches, dizziness and stomach upsets. 

However blind trials, where participants didn’t know if the product they consume has the sweetener, have failed to replicate this.

But there have been broader health concerns for years, including that it causes cancer, alters the gut biome, triggers depression, and paradoxically even contribute to obesity by increasing people’s appetites.

Yet health and food regulators have repeatedly declared them safe to use following ‘rigorous’ safety assessments.

There is one exception, however. People with phenylketonuria, a rare inherited blood condition, cannot process phenylalanine — one of the building blocks of aspartame.

If people with phenylketonuria consume phenylalanine it can build up in their blood, eventually damaging their vital organs. 

For this exact reason, aspartame must be listed as an ingredient on any product that contains it in both the US and UK, as well as other countries. 

Only about one in 10,000 people have the condition.  

What does the potential ruling mean?

The bombshell decision means the WHO’s subsidiary body, the International Agency for Research on Cancer (IARC), will officially link aspartame consumption to cancer.

However, it is expected to get a ruling of 2B, according to Reuters. 

This means it is ‘possibly carcinogenic to humans’. 

This is the middle of five categories, and means ‘there is some evidence that it can cause cancer in humans’. At the same time, the link is ‘far from conclusive’.

The IARC’s same 2B cancer risk status is also given to Aloe vera extract, lead, and several colouring agents. 

For comparison, red meat is considered ‘probably carcinogenic to humans’ or 2A — one stage above aspartame’s expected bracket. 

The IARC has previously the radiofrequency electromagnetic fields emitted by mobile phones as a 2B cancer risk and acrylamide, the brown-black substance that forms on food from frying or baking, as a 2A cancer risk. 

IARC rankings are based on the evidence base that a substance or hazard poses a carcinogenic risk to people and not the individual risk.

For example, both smoking tobacco and processed meat a classified as 1 for cancer risk, meaning the evidence basis linking the substance to an increased risk of cancer is very strong.

However, it does not mean bacon is as carcinogenic as smoking. 

Will Diet Coke be slapped with cancer warnings then?

Such rules are left up to individual countries.

But no similar warnings have been placed on red or processed meats in the UK despite stronger links to cancer being found according to past IARC rulings.

Any attempt to include such a warning would likely be considered an overreaction and would face stiff opposition from the soft drinks and sweetener industries.

Those opposed to the creep of ‘nanny-statism’ would also campaign against it.

But it could, if the evidence base is strong enough, lead to a recommended intake for aspartame by health authorities, for example the NHS.

This, depending on what experts find, could lead to Brits being advised to only consume one product containing aspartame per day or week, for example.

Such warnings could be published in health information similar to the NHS’s Eat Well guide. 

How much aspartame is safe to consume?

Even if aspartame is declared ‘possibly carcinogenic’ to humans, an individual’s risk could vary immensely.

The IARC establishes its rating based on evidence linking a substance to cancer, not the actual risk itself. 

Safe consumption levels would be determined by a separate body, the Joint WHO and Food and Agriculture Organization’s Expert Committee on Food Additives.

It would provide advice on individual consumption levels, which could then be adapted by national health bodies.

The current recommendations for safe daily aspartame consumption are 50mg per kg of body weight in the US and 40mg per kg of body weight in the UK. 

This puts the British recommendation at about 2800mg for a 70kg adult.

Considering the average can of Diet Coke contains 180mg of real aspartame the British Dietetic Association says an adult would need to consume 15 cans a day to reach the acceptable daily intake of the sweetener. 

Will manufacturers face backlash?

Any IARC ruling on aspartame’s cancer risk could prompt consumer backlash, with customers shunning products containing them over cancer fears.

Similar boycotts have occurred from other IARC rulings.

In 2015, its committee concluded that glyphosate, a herbicide, is ‘probably carcinogenic’.

The ruling is often cited as a reason the product was banned in various countries, and many more individual states, cities or local government have also enacted rules against its use. 

Such consumer backlash on aspartame could, in theory, lead to food and drink companies changing the formulation of their products.