I won't eat artificial sweeteners.
That's certainly not because I buy into the conspiracy theories, some of which contend these were introduced into the food supply to kill people on purpose. Really, that's just silly.
But it's also not because I think the prevailing sweeteners are terrible toxins. There is a case to make that aspartame can adversely affect the nervous system. But there is a case to make that peanuts can cause life-threatening allergy. We have not concluded as a result that peanuts are poison; we've just concluded that some people are sensitive to them and need to avoid them. That appears to be the case with aspartame as well.
There are concerns about sucralose and cancer, but to my knowledge, no real evidence of any harm. And concerns about saccharin and cancer may have been valid but misdirected. Sweet'N Low actually contained something called cyclamate along with saccharin, and current thinking is that cyclamate may have carcinogenic potential, while saccharin likely does not.
[Read: Are We Sugar Crazy?]
We needn't go too deep into these weeds, and there's no particular need to get very specific about the prosecution and defense of aspartame, saccharin, sucralose, acesulfame-k or any other sweetener. We can get most of what we need with a view from altitude.
Artificial sweeteners are massively prevalent in our food supply. If we think in terms of servings consumed, it must number in some huge multiple of billions, perhaps trillions. Certainly, hundreds of millions of people have been exposed, in some cases for decades. During all that time, we have had diligent epidemiologic surveillance conducted by the likes of the U.S. Centers for Disease Control and Prevention and the Surveillance, Epidemiology and End Results (SEER) Program, the latter being a cancer surveillance program of the National Cancer Institute.
If artificial sweeteners were causing any meaningful, overt harm – the simple fact is, we would have seen it. Imagine trying to do serious harm to hundreds of millions of people and NOT having it become obvious! In fact, over the decades that these chemicals have disseminated throughout our food supply, cancer rates have declined substantially.
[Read: Seeking a More Perfect Supply.]
But lest you think I am here to defend rather than bury artificial sweeteners, let me remind you where we started: I won't eat them! There are several reasons why.
1. The precautionary principle
If any of the widespread artificial sweeteners were causing a whole lot of very direct harm, we would have seen it. But that by no means precludes a whole lot of subtle, perhaps indirect harm we can't see. We don't know why the incidence of ADD/ADHD is rising, although I have some thoughts on the subject. We can't readily account just yet for the rising prevalence of autism. We don't know the specific causes of chronic fatigue syndrome, fibromyalgia or irritable bowel syndrome, to name just a few.
Is it possible that chemicals in our food, to which we of course have no native adaptations, are contributing to some or all of this? Of course it's possible. It may even be probable. The precautionary principle argues that we don't assume something is entirely safe just because we don't have proof that it's dangerous. These are chemical compounds, not food – and we know our native diet was made up of food.
[Read: The Myth of Healthy Processed Food.]
2. The burden of proof
Much attention has recently been paid to diet soda, the stand-out vehicle for artificial sweeteners in our diets, in both the research literature and the popular press. The current conclusion is that while we don't know for sure that diet sodas and artificial sweeteners cause Homo sapiens to overeat and get fat – as they appear to do in other species – we don't have conclusive evidence to rule that out, either. In other words, there is no well-established case that "diet" sodas actually help with "dieting" (a very questionable practice in its own right, but that's a different story).
The only putative advantage of making sweet chemicals a part of our diets is the calories and sugar they take out. If they don't really do that, there is no excuse for them whatsoever. Perhaps they do help with this, but the burden of proof resides with those claiming the benefit, not with those of us who doubt it. If something implies it helps with dieting, there should be evidence of that benefit. Such evidence as exists is murky at best.
So, in other words, it is far from clear that artificial sweeteners do the very thing they were designed to do. The burden of proof, in my view, has not been satisfied – and neither am I.
3. The sweet tooth
There has also been a whole lot of attention recently, again in both the research literature and popular press, around the issue of sugar being addictive. And once again, we need not wade too deep into controversy to extract what we need.
We refer, in the vernacular, to a "sweet tooth," not a sugar tooth, and we have it exactly right. Sweet is a neurophysiological response – it's the way particular nerve cells communicate their awareness of a particular stimulus to the brain. The reaction is much the same, no matter what the sweet stimulus is. As the "sweet tooth" expression suggests, it's sweet we like and sweet we want. That sweet can come from sugar, or corn syrup, or agave or aspartame. Sweet is sweet.
The questions about addiction notwithstanding, it is pretty clear that the more sweet we get, the more we tend to need to feel satisfied. Bathe taste buds in sweet all day long, and they need much higher concentrations to take notice. And that's just what artificial sweeteners do. Those sweeteners now predominant in the food supply range in sweetness intensity from 600 to roughly 1300 times as sweet as sugar.
My impression – based in part on 20 years of clinical experience – is that feeding a sweet tooth with sweetness from any source helps it grow into a sweet fang, much inclined to take over your appetite and your life.
[Read: What Makes a Healthy Diet?]
4. The better way
And finally, there is the "who needs them, anyway?" argument. Even the most ardent defenders of sugar substitutes don't argue that they are actually GOOD for us! The very best case that can be made for artificial sweeteners is all about what they take out of our diets – sugar and calories – not what they add.
So the goal here is to take sugar and calories out of our diets, not to add aspartame or saccharin. It's a good goal, since by and large, we consume way too much of both. But it's not clear, as noted, that artificial sweeteners actually help with this – and there certainly is a better way.
[Read: How to Overcome Your Sugar Addiction.]
Because of programming my lab has developed for kids and adults alike, and related research we have done over the years, I have a pretty intimate knowledge of the ingredients in thousands of foods. Looking through that window, it becomes clear that there is sugar everywhere! There is sugar in all the places you expect it, and all the places you don't. Bread should not need added sugar – but many breads have it. So do many crackers. So, too, do many pretzels and even some chips.
No one I know would pour packets of sugar over lettuce, but many commercial salad dressings are highly concentrated sources of added sugar. No one I know would pour packets of sugar over pasta, but some commercial marinara sauces are more concentrated in added sugar than ice cream topping. Really!
I refer to all of this as "stealth sugar," and it's a problem in two ways. First, sugar is added to food that isn't even sweet as a goad to appetite – it causes us to eat more before feeling full. Related to a well-studied phenomenon called sensory specific satiety, that, too, can be a story for another day.
The other way in which that stealth sugar is a problem is the obvious one: It bathes taste buds in sugar they barely notice, causing them to need ever higher doses of sugar to notice. The sweeter your pasta sauce, the sweeter you tend to like your dessert.
But there is an opportunity here as well: This menace can be reverse engineered. You can take gram after gram of sugar out of your diet before ever even touching the foods you thought of as sweet in the first place. And by doing that, you can file your sweet tooth down to size. Before long, you will find yourself content with seltzer or even water in place of soda; before long, the dessert you used to like best will taste too sweet. I have worked with patients innumerable times over the years to remove copious additions of stealth sugar from their diets and then move on to the sugar that was obvious. It works, no chemicals required.
[Read: Recipe for Health.]
So there you have it. I do not buy into the hyperbolic conspiracy theories about artificial sweeteners but see no need to go that far to make the case against them. They are just too darn sweet for the sweet spot.
As a public health pragmatist, I often find myself advising my colleagues that we should not make perfect the enemy of good. There is a corollary that doesn't get as much attention: We should not make horrendous the enemy of bad, either.
I don't think artificial sweeteners are horrendous; I just think they're bad. My point is that bad is bad enough.
Hungry for more? Write to firstname.lastname@example.org with your questions, concerns, and feedback.
David L. Katz, MD, MPH, FACPM, FACP, is a specialist in internal medicine and preventive medicine, with particular expertise in nutrition, weight management, and chronic-disease prevention. He is the founding director of Yale University's Prevention Research Center, and principal inventor of the NuVal nutrition guidance system. Katz was named editor-in-chief of Childhood Obesity in 2011, and is president-elect of the American College of Lifestyle Medicine.