I have a fraught relationship with the WHO (World Health Organization). On the one hand, their campaigns in the areas of infectious disease, famine, poverty, and public health are admirable. On the other hand, when it comes to communicating cancer risk of the foods we eat, they quickly lose my admiration.
Their most recent cancer (mis)communication had consumers asking the question: Is my diet soda cancer in a can? The WHO, killjoys that they are, decided to categorize aspartame (NutraSweet) as a “Possible Carcinogen”. Should you worry about that can of diet coke you drink with lunch? Let’s dig into the headline hype and talk about the organization’s faulty communications on cancer.
One of the biggest problems with the WHO’s cancer categorization is how they classify carcinogens and then fail to explain it to the public. The WHO has quite a knack for issuing confusing proclamations about what might and might not cause cancer. The way they categorized carcinogens, particularly food, is often misleading and confusing. Take a look at the categories.
WHO Categories of Carcinogens:
Group 1: Carcinogenic to Humans
· Sufficient evidence of causing cancer in humans
· Smoking, alcohol, and processed meat
Group 2A: Probably Carcinogenic to Humans
· Limited evidence of causing cancer in humans but sufficient evidence of causing cancer in animals
· UV radiation, red meat, anabolic steroids
Group 2B: Possibly Carcinogenic to Humans
· Limited to inadequate evidence of causing cancer in humans, sufficient evidence of causing cancer in animals.
· Coffee and aspartame
Group 3: Not Classifiable as Carcinogenic to Humans
Group 4: Probably Not Carcinogenic to Humans
These groupings can be deceiving because they don’t quantify your risk. They show risk identification – not risk quantification. Notice that both processed meats and smoking are in the same, riskiest category. But obviously processed meats are not nearly as bad for you as smoking. Smoking a pack of cigarettes a day over 20 years increases your chances of getting lung cancer by a relative risk of 1900%. Eating 1.7 ounces of processed meats every day is associated with an increased relative risk of 18%. An 18% increased relative risk is not all that high as relative risks go - especially when you compare it to smoking. I'm not saying go whole hog on the bacon and ham but a sausage and eggs breakfast on Sunday isn't going to kill you.
Aspartame, the stuff that’s likely in your diet soda, is in the possibly carcinogenic category (the second lowest category) which means that there is limited to inadequate human data. The studies that the scientists used to land aspartame in the possible carcinogen category do not show cause and effect – they only show associations or correlations. They are observational studies and are generally considered weak in the field of nutrition research. You’ll also notice it’s joined there by coffee. Yes, that’s right – the drink that for many of us makes mornings bearable.
Here’s What I Recommend:
· Read Beyond the Headlines: Headlines are clickbait. Reading the entire article will help you find the nuances and caveats and help you make an educated choice. Usually the limitations of the studies and evidence are in the lower third of the article.
· Don’t Overdo It. If you enjoy a one or two diet sodas a day (12 ounces each) there is no need to stop. One thing this designation does not recommend is changing the guidelines for safe aspartame consumption. The guidelines stay the same for aspartame safety: no more than the equivalent of 13 cans of diet soda a day for a 150-pound person. That’s a lot and I don’t recommend that you drink that much.
· Cut Other Sources of Aspartame. You may be getting more than you think so read your labels!
· Don’t Switch to Sugary Drinks! While some sugar is fine, too much can add weight and replace healthier foods and drinks.
· Switch to Other Drinks. If you still feel that you’d rather not drink any diet drinks at all, that’s fine. There’s nothing inherently healthy about aspartame and other noncaloric sweeteners. Water is great but if you find it boring (like I do!) switch to lightly sweetened iced tea, sparkling water, or add lemon and lime slices to water to jazz it up!
I’ll close with this statement from Dr. Mitrou of the World Cancer Research Fund while I wait for the next scream-inducing headline:
Many may be worried to hear that the artificial sweetener, aspartame, has been classified as ‘possibly carcinogenic’. The evidence for a direct link between aspartame and cancer isn’t strong, so aspartame is unlikely to cause harm if consumed within safe levels.
-Dr. Panagiota Mitrou, Director of Research, Policy and Innovation at the World Cancer Research Fund
Beth Kitchin PhD RDN