Aspartame is an artificial sweetener that is used in more than 6000 different food products ranging from diet sodas to chewing gums. It is known to be 200x sweeter than regular sugar and only a small amount is needed.

However, recently WHO has made a statement that aspartame is “possibly carcinogenic (cancerous) to humans“ and as per the International Agency for Research on Cancer (IARC), aspartame falls into Group 2B.  

So, what does this classification mean?

There are 5 different categories developed according to carcinogenicity by International Agency for Research on Cancer (IARC).  Below is the interpretation of each category:  

Group	What Does it mean?	Examples
1	Sufficient evidence that items cause cancer in humans	-Smoking -Exposure to solar radiation -Alcohol -Processed meat
2A	Limited evidence of cancer causing in humans. Sufficient evidence in animals.	-Emissions from high temperature frying -Steroids -Red meat -Exposures to chemicals in hairdressing environment
2B	Limited evidence of cancer causing in humans. Insufficient evidence in animals.	-Pickled vegetables -Gasoline -Welding fumes
3	Inadequate evidence in humans and animals	-Tea -Static magnetic fields -Fluorescent lighting -Polyethene
4	Evidence suggest no cancer causing ability in humans/ animals	-Caprolactam (used in the manufacture of synthetic fibres) — only 1 chemical ever placed in these category

** Substances in the same group tells us the level of carcinogenicity of each item but does not tell us the relative risks.

To conclude it all, these declaration as of now is a risk assessment- the probability of a specific type of harm (e.g. cancer) to occur under certain conditions and levels of exposure.

As of now, the Acceptable Daily Intake (ADI) of 40 milligrams per kilogram of body weight per day (mg/kg/BW/day) remains. This is equivalent to drinking 36 cans of diet soda.

Hence, be wary of the amount of aspartame one consumes. Always check the nutrition label.

References:

1. Exclusive: WHO’s cancer research agency to say aspartame sweetener a possible carcinogen –sources. Reuters.

2. Aspartame – is it a possible cause of cancer?. BBC News.