What You Should Know About Aspartame, SIBO
Q&A: Looking deeper into recent controversy over the artificial sweetener, plus more on gut health (SIBO edition)
Welcome back to Rethinking Wellness! In these biweekly Q&A newsletters, I answer audience questions about wellness culture, including whether particular diets are warranted, the truth about supplements and other protocols, how to spot wellness scams, and lots more. You can ask your own question here for a chance to have it answered in an upcoming edition, and some of these Q&As may end up in bonus episodes of the podcast as well.
Just a reminder that these answers are for educational and informational purposes only, and not a substitute for medical or mental-health advice. Although I am a registered dietitian, I’m not your dietitian (unless you happen to be one of my 1:1 clients—hi!—but even then, this email isn’t a session).
Without any further ado, let’s get to the questions!
The first question today is available to all subscribers (about aspartame and cancer risk), and there’s a bonus one for paid subscribers (about small intestinal bacterial overgrowth, or SIBO).
What is your input on the FDA vs WHO debate on artificial sweeteners?
—Katelyn
In case you missed it, last month the World Health Organization (WHO) released a statement about aspartame, the widely used artificial sweetener, suggesting it could be linked to cancer in humans. The news struck fear in the hearts of many readers, as nutrition-related headlines often do. Some wellness influencers took this as an opportunity to reinforce their negative views on artificial sweeteners, and old conspiracy theories about aspartame were given new life.
Then, on July 14, the U.S. Food and Drug Administration (FDA) responded to the WHO’s classification, disagreeing with its “possibly carcinogenic to humans” label and arguing that the scientific studies cited by the WHO had “significant shortcomings.”
I personally agree with the FDA’s stance on this. Labeling a food item as “possibly carcinogenic” without solid scientific evidence can lead to unnecessary fear among the public, helping to fan the flames of diet and wellness culture.1
The studies that informed the WHO’s classification do have major limitations: For starters, most of them are observational, making it hard to distinguish between correlation and causation. The research also mainly focused on artificially sweetened beverages rather than aspartame consumption specifically.
Interestingly, even within the WHO, there’s disagreement on this issue. On the same day, two separate WHO divisions published reports on aspartame: One (the International Agency for Research on Cancer) labeled it as “possibly carcinogenic,” while the other (the Joint FAO/WHO Expert Committee on Food Additives) maintained its previous stance on acceptable aspartame intake.
Speaking of which: the upper limit on aspartame set by the WHO is quite high. It’s based on body weight, and I won’t give specific weight numbers out of respect for readers recovering from disordered eating—but I will say that most Americans can consume about 14 cans or more of diet soda per day without exceeding the limit. Again, this recommendation hasn’t changed since the “possibly carcinogenic” classification.
In other words, even by the WHO’s relatively strict standards (the FDA’s upper limit is slightly higher), consuming multiple servings of aspartame-containing products daily shouldn’t be a problem. The idea spread by some wellness enthusiasts that aspartame is “literal poison” at any dose is simply incorrect.
But there’s more to this story that many media outlets are missing, which they often miss: the role of disordered eating.
Though I don’t think we need to freak out about aspartame, I do think that if you’re consuming lots of artificially sweetened products every day, it’s important to examine your relationship with food and your body.
For one thing, drinking diet soda or chewing gum in order to curb hunger and avoid food is a well-known sign of disordered eating. So is constantly consuming artificially sweetened foods because you’re craving sweets but not allowing yourself to have sugar. (For some people with diabetes this can be a little more complicated, as artificial sweeteners can sometimes be helpful for blood-glucose management—but even then, real sugar still is not the scourge it’s made out to be, and excessive consumption of artificial sweeteners still may be a sign of disordered eating.)
If you’ve been told your body size is a problem and that you need to lose weight for health/wellness, you might be turning to artificial sweeteners as part of a weight-loss diet. But even low-level dieting can still put you at risk for rigid dieting and eating disorders.
In all these situations, you deserve help and support to help let go of the negative beliefs about food and your body that are likely driving these behaviors. And for many people, when they start to heal their disordered relationship with food, their artificial sweetener consumption declines or even disappears. When you’re no longer dieting or restricting sugar, you may not crave artificially sweetened foods as much—or at all.
Granted, some people may genuinely prefer the taste of artificially sweetened products like diet soda. There was a famous Diet Coke ad campaign to that effect when I was growing up, and there’s been a similar effort to position Coke Zero as a purely aesthetic choice.
But if you fall into that camp, I’d be curious: if you’re really honest with yourself, how much of that taste preference do you think is due to lingering diet-culture beliefs? If you had never restricted your eating or thought sugar was bad, would you have given diet soda the time of day? Even if you did, do you think you would have made it such a habit if you weren’t restricting?
If you truly love the taste of artificial sweeteners even when you’re definitely not dieting, cool! (People like that do exist, including friend of the pod Virginia Sole-Smith.) But I’d encourage you to critically examine your relationship with these products—and to wait until you’ve truly stopped dieting before you decide whether this really is a taste preference that you want to reclaim.
Thanks so much for the great question, Katelyn, and thanks to all the free subscribers for reading! Paid subscribers can stick around for the bonus Q&A, and everyone can ask their own questions for a chance to have them answered in an upcoming newsletter.
Hi Christy, I've struggled with gut issues for many years, and I'm really grateful for everything you've written on this topic—your books, newsletters, and podcasts give me hope that elimination diets and aggressive protocols are not the only routes to healing, and could even be counterproductive, especially for people with eating disorder histories.
However, I'm still really struggling to know what is going on with my gut, and am afraid to go back to traditional doctors, as their advice (laxative cleanses, restrictive diets) has been harmful to both my physical and emotional health. My list of intolerances seem to keep growing; initially I thought I was gluten-intolerant, but now I am reacting to all carbs: gluten-free bread, cereal, oats, and even simple sugars like fruit and juice. I don't think it is nocebo because I have never had a fear of carbs, even in my eating disorder, carbs were "safe" in my mind.
Now I don't know what to believe. You've mentioned in past newsletters that the GI Map test is problematic, so I don't even know how to go about diagnosing the problem. My symptoms match the criteria for SIBO [small intestinal bacterial overgrowth], and the most common piece of advice I've received on that front is to "starve the bad bacteria" by cutting out food groups. However, as someone with a history of anorexia, this concept is very triggering—I don't know how to starve the bacteria without starving myself. Do you have any thoughts on this? Thanks so much.
—Priya