Aspartame, a sweetener commonly found in diet drinks and chewing gum, has been declared a potential cancer risk by the World Health Organization (WHO).
The sweetener has been listed as “possibly carcinogenic to humans.”
The World Health Organization’s cancer research arm, the International Agency for Research on Cancer (IARC), said there was “limited evidence” Aspartame causes cancer in humans.
“While safety is not a major concern at commonly used doses, potential effects have been described and require investigation,” said Dr Francisco Branca of the World Health Organization.
He added in his advice to the public: “If a consumer is faced with the decision of whether to drink a sweetened cola or a sweetened cola, I think there is a third option that should be considered – and that is water.”
If the evidence is limited, why did the World Health Organization make this statement?
The scale used by the International Agency for Research on Cancer indicates the level of evidence that a substance causes cancer.
IARC uses four categories: 1 – Causes cancer; 2A – Likely causes cancer; 2B – Likely causes cancer; 3 – No evidence of cancer risk.
Based on limited evidence in human cancers (specifically hepatocellular carcinoma, a type of liver cancer), aspartame is classified as 2B, “probably carcinogenic.”
Other possible 2B carcinogens in this group include aloe vera, ferns, lead, and hairdresser’s work.
The scale doesn’t say how much you need to be exposed to to increase your cancer risk, it just identifies the substances as dangerous.
Alice Davies, Cancer Research UK’s health information manager, told Sky News: “Being classified as a carcinogen doesn’t tell you how much it increases your cancer risk.
“Sometimes there are substances that theoretically could cause cancer, but in reality, you’re exposed to too low a dose to increase your risk.
“For example, processed meat and smoking are both carcinogens, but smoking causes about 54,000 cases of cancer in the UK each year, while processed meat only causes about 5,400.”
So how much aspartame can I take in a day?
This is where another arm of the World Health Organization comes in, the Joint WHO and Food and Agriculture Organization Expert Committee on Food Additives (JECFA for short).
JECFA reviewed data on aspartame intake and said adults can safely consume up to 40mg per kilogram of body weight.
This does not change the previously recommended daily limit.
This means that an adult weighing 70 kg can consume 2800 mg of aspartame per day.
Aspartame is found in beverages including Coke Zero, Diet Coke, Diet Pepsi, Pepsi Max, Zero Sprite, and Zero Fanta.
A can of diet drinks typically contains about 200 mg of aspartame. Therefore, a 70 kg adult can drink 14 cans without exceeding the safe daily limit of aspartame.
What do carcinogens do to your body?
Cancer is a disease of cells, and carcinogens are substances that disrupt the way cells work.
Ms Davies, from Cancer Research UK, said carcinogens could damage the cells themselves, as well as your DNA.
For example, genes that normally prevent cells from replicating too much could become damaged, causing cells to multiply uncontrollably.
Do I need to worry about aspartame causing cancer?
Instead of worrying about the things that might cause cancer, Ms Davis said it was better to address the established causes of cancer, such as smoking, alcohol and obesity.
“The most important things you can do to reduce your risk of cancer are not smoking, maintaining a healthy weight, eating a healthy, balanced diet, reducing alcohol consumption and being physically active.”
The Food Standards Agency (FSA) agrees. It said people need not be concerned about the JECFA report on aspartame as long as they followed the existing advice.
Professor Robin May, FSA Chief Scientific Advisor, said: “The JECFA report supports the FSA’s view that aspartame is safe to consume at the levels currently permitted for use.”
The International Agency for Research on Cancer and the World Health Organization will continue to monitor emerging evidence and encourage further research on the potential link between aspartame and cancer by independent research groups.
The FSA welcomed the additional research, calling for “more and better research” on the potential risks of aspartame consumption.