Consumer Alert: Does your diet Coke cause cancer? What the new aspartame classification means

Does your diet Coke cause cancer? That’s the question consumers are asking after a committee of the World Health Organization, the International Agency for Research on Cancer or IARC, categorized aspartame as “possibly carcinogenic to humans.” And this is a shocker: Aspartame is one of the most used artificial sweeteners in the world. It’s in more than 6,000 products around the globe — everything from your diet soda to your gum, even your toothpaste. So of course, consumers are concerned.

But let’s put it in perspective. The IARC has four categories for substances.

• Category one: Carcinogenic to Humans. This is the worst category. Cigarettes and asbestos fall in this category.
• Category two: Probably carcinogenic. This classification indicates there’s strong evidence in animals but more research is needed.
• Category three: Possibly carcinogenic. This classification indicates there’s limited evidence and the committee believes more research is needed.
• Category four: Not classifiable as to its carcinogenicity to humans. In this class, there is not enough evidence to classify the substance.

The IARC includes aspartame in its third category, possibly carcinogenic, but that doesn’t mean your diet Coke will give you cancer. It means there is some evidence to indicate the aspartame needs more study. In addition to aspartame, other substances labeled possibly carcinogenic are aloe vera, Asian pickled vegetables, some vehicle fuels and some dry-cleaning chemicals.

And it’s important to note another committee of the WHO has not changed its recommendations for daily maximum intake of aspartame, which is 40 milligrams per kilogram of body weight. Most diet sodas have around 100 milligrams of aspartame. That means someone who weighs the American average of 83 kilograms, or 184 pounds, could drink up to 33 cans a day and stay within the limits. And you’d have to consume the equivalent of 33 cans of diet soda every day for a long period of time.

It’s also important to note this classification is controversial. The FDA does not agree. A spokesman told CNN the FDA believes the research that the IARC relied on had “significant shortcomings.”

So that brings us back to the question: Should you limit your diet coke? Sure, just as you limit your red meat and natural sugars. There is wisdom in the old adage, “all things in moderation.”