Welcome to Nutrition Bites. The no nonsense podcast where you get the truth about food so you can eat what you want and be healthy. I’m your host Maggie and welcome to the series! We are biologically built to crave sweetness, but too much sugar is not great for us. Fortunately we have a lot of alternatives available, but how much healthier are they compared to the real stuff? On the menu today, sugar substitutes. Artificial sweeteners. Sweeteners.
Over the past two months I’ve been on a personal food journey. Having recently switched to a mostly vegetarian diet, I’ve been struggling to meet my daily protein needs. There’s only so much tofu, lentils and beans I can eat before my bloated stomach makes me airborne. So to help bump up my protein intake I’ve decided to dabble into the world of protein powders. But in entering this space I feel how I imagine many Dad’s do shopping in Sephora: confused, overwhelmed, and slightly scared. There are just way too many options! And it doesn’t help that the label claims are outrageous, the flavours are confusing, and the brand names are downright aggressive. But beyond this pomp and circumstance one particular aspect that I struggled with was finding an option without any added sugar or sweetener. Now I eventually discovered a protein powder that fit my needs but the unsweetened version I ordered tasted positively offensive. After consulting with friends who also use protein powders, their advice was simple: just pick a sweetened option ya dummy. After all, sweeteners are a common ingredient in protein powders. And more importantly, are they really something to be concerned about? But with years of nutritional shame and media negativity around sugar substitutes in general, I’m still not immediately comfortable with adding them into my daily diet. But for the sake of my tastebuds, perhaps it’s about time I check my own assumptions and figure out the truth behind sugar substitutes.
Sugar substitutes, also called low-calorie sweeteners or non-nutritive sweeteners, are substances that provide a sweet taste while contributing few or no calories. They are primarily used as an additive in packaged foods and beverages - like Diet Coke or sugar-free gum. Some sugar substitutes are also available as a standalone ingredient. Like those colourful packets of Sweet’n Low or Splenda you can add to your coffee, or a bag of powdered stevia available at the grocery store. The main benefit of sugar substitutes is that they provide an option for people to consume sweet foods and drinks while helping to reduce their overall added sugar and caloric intake. And in theory, this can provide assistance with weight management and blood sugar control. You can have your cake, eat it too, and not suffer any consequences.
Sugar substitutes are so commonly used because of just how strongly they trigger our perception of sweetness. Sweet is one of the five basic tastes, and we perceive this sensation thanks to receptors on our tongue (aka taste buds). When these specific receptors interact, or bind, with the right molecules a signal is sent to the brain that we’re eating something sweet. The stronger the bond between the molecule and receptor, the sweeter the taste. Some substitutes actually have a much stronger bond than sugar, which means you only need to add a tiny amount of the molecule in order to get an insanely sweet effect. Because the volume of sweetener needed is so small, the amount of calories they contribute is minimal. Other substitutes by-pass metabolism all together, therefore contributing no calories to your system. But in the grand scheme of things, whether a sugar substitute is a low- or no-calorie sweetener is not so important. What’s more interesting is their origin.
The terms artificial sweeteners and natural sugar substitutes get thrown around a lot in the nutrition world - with one being demonized and the other viewed as a holy grail ingredient (I’ll let you figure out which is which). Now in general, there are three main categories of sugar substitutes: artificial, natural, and sugar alcohols. For a variety of reasons, much of the distrust and skepticism of sugar substitutes is focused on artificial sweeteners, so that’s where we’ll be focusing this episode. But it’s still important to learn a little about natural sugar substitutes and sugar alcohols because they are so prevalent in our diet.
The most common natural sugar substitute on the market is stevia, a molecule 200x sweeter than sugar and sourced from the leaves of the South American stevia plant. Although consumed for hundreds of years by indigenous peoples in this region, Stevia has only been approved for use in North America, Europe and Australia since the early-mid 2000s. Because it is a zero-calorie, plant-derived, high-intensity sweetener - it has received a lot of positive backing from anti-sugar wellness advocates. That said, we also don’t have too much long-term research on stevia so TBD on if it actually deserves its health halo.
Sugar alcohols are a group of plant-derived molecules including sorbitol, xylitol, maltitol, erythritol, and any other difficult-to-pronounce word ending in -ol. They are actually less sweet than sugar, however, their prime advantage is that they don’t cause tooth decay or cavities. So you’ll often find these molecules added to sugar-free chewing gums, candies, and even in mouthwash and toothpaste. One drawback to sugar alcohols though is that they are highly fermentable which if you listened to Episode 39, you know that means they can cause some intense bloating and digestive issues.
All in all, most people aren’t fussed with sugar alcohols or stevia. The Big Bad Wolf of the sugar substitute world is artificial sweeteners. Artificial sweeteners are synthetic substances, many of which were discovered in the 1960s and 70s when scientists accidently licked their fingers after mixing chemicals in the lab. True story..and it happened more than once. The four most popular artificial sweeteners today are: aspartame, acesulfame-potassium (also called Ace-K), saccharin, and sucralose (which you probably known as Splenda). Many of these sweeteners have been approved for decades in the US, Canada, EU, Australia and other regions. The safety of these substances has been rigorously evaluated and each sugar substitute has an acceptable daily limit - essentially the max amount one could ingest safely every day for the rest of their life. And these limits are insanely high, so one diet pepsi, or a pack of splenda in your coffee, is perfectly safe. But apart from the obvious products that contain artificial sweeteners, where else can we find these ingredients?
Well, the first place to look for any sugar substitutes are products which are branded sugar-free, diet, or use the label “light”. Think diet pop, keto or paleo snacks, sugar-free protein bars, and light yogurt or ice cream. By far the most commonly consumed sugar substitutes are artificial sweeteners found in low- and no-cal sodas like Diet Coke and Pepsi Zero Sugar.
But while you can somewhat easily avoid buying these obvious products, sugar substitutes often sneak attack their way into other foods and drinks. For example, they may be used alongside a real sugar source simply to reduce the overall amount of added sugar needed in a product. On a recent trip to the grocery store I found a kombucha drink that contained both cane sugar and stevia. I also found a protein bar which contained maltitol (a sugar alcohol), sucralose (an artificial sweetener), and fructose (which is regular sugar). Case and point - these substitutes can be found all over, and so you really have to scrutinize the ingredients list to find out if you’re consuming them or not.
Now contrary to the preachings of food conspiracy Facebook groups, if you happen to consume a product with artificial sweetener, you don’t have to worry about your DNA mutating or spontaneously developing cancer. These ingredients are safe and there are virtually no short-term side effects. The only notable one is a weak link between aspartame and headaches, so if you suffer from chronic migraines be mindful. But the bigger concern out there is what happens in the long-term if you regularly consume artificial sweeteners.
One of the advantages of low- and no-calorie sweeteners is that they can be used to help prevent weight gain. But newer observational studies are showing that regular consumption of artificial sweeteners, mostly in the form of low- and no-cal sodas, may actually cause us to gain weight. Now the overall results in this field are mixed, with studies showing weight loss, others showing maintenance, and others weight gain. But that’s still not a particularly comforting outcome for an ingredient whose purpose is to help people reduce caloric intake. The same conflicting result has been found in relation to Type 2 Diabetes. Sugar substitutes in general are often promoted as a good choice for diabetics as they do not raise blood sugar. But some observational studies are now showing an association between consumption of these substitutes, particularly in diet sodas, with an increased risk of developing Type 2 Diabetes. Now before anyone calls for big soda to be canceled, and trust me I’d be first in line, the researchers of these studies have pointed out that reverse causation may be to blame. For example, people already at risk of developing Type 2 Diabetes may be told to begin drinking these artificially sweetened beverages to improve their blood sugar control. This then produces a false association between intake of artificial sweeteners and risk of developing diabetes.
A different long-term health association of artificial sweeteners is with cancer. Even as a teen I remember hearing about how aspartame causes brain tumors, most likely from an embellished Dr. Oz episode. Now the artificial sweetener and cancer link stems from two old studies: one on aspartame and the other on saccharine. Both studies have been heavily criticized by scientists, and to keep it short, the original authors made pretty outlandish, and strategically newsworthy, conclusions from crappy data. Today organizations such as Cancer Research UK and the US National Cancer Institute explicitly state that these sweeteners do not cause cancer. But to stir the pot a little bit, this year’s theme is chaos after all, a new study published a few months ago suggests that perhaps we shouldn’t be so dismissive of the cancer link just yet. An evaluation of over 100,000 French adults, showed an association between high consumption of artificial sweeteners and an increased risk of breast, stomach, liver, and colon cancer. Specifically, adults who drank high volumes of diet sodas had an increased cancer risk compared to people who never consumed artificial sweeteners. Now I hope by now you know that we can’t conclude anything based on one result from one study. But what this does highlight is the need for more research. And that can be said for all the suspected long-term health effects of artificial sweeteners - especially because the blame seems to heavily lie on diet sodas rather than the sweeteners as a standalone ingredient. But while more real-world evidence is being gathered, researchers are also investigating the exact mechanisms by which artificial sweeteners, and sugar substitutes in general, may be causing these long-term health issues.
The overarching theory boils down to this: you can’t shortcut the human body. Whenever I hear an influencer try to sell their audience on ways to trick the body, I want to send them to Azkaban for defamation of a biological masterpiece. The idea of a substance sending a sweetness signal to our brain without providing any calories that real sugar is known for, sounds exactly like the type of scam the body wants to punish us for participating in.One reason that researchers suspect sugar substitutes may actually cause weight gain is related to a concept called the reward theory. The neurological reward system plays an important role in regulating our energy intake. When we want something sweet and act on it by consuming sugar, signals are sent to the brain to let it know the craving has been satisfied. But when we try to soothe our sweet craving with sugar substitutes, scientists think that this satisfaction signal is much weaker. And this may lead to involuntary over consumption as you are triggered consume more, or other, sources of sweetness to try to gain that neurological reward. A related mechanism also thought to be at play here is called caloric intake compensation. Because sugar substitutes contribute so few calories, some people may use this as an excuse to over consume elsewhere in their diet. Like upping their fry order to extra-large because they ordered a diet soda. Of course this kind of choice effectively cancels out the caloric benefit of consuming a sugar substitute in the first place.
Another suspected mechanism regarding the impact of sugar substitutes on long term health is related to my favourite fermenting place - the gut. The gut microbiome is a sensitive environment and incredibly influenced by what we eat and drink. The trillions of microorganisms that exist in our gut play a crucial role in our overall health, and some scientists suspect that sugar substitutes may alter the composition and function of these tiny creatures. Such changes could very well negatively influence our metabolism, weight regulation and blood sugar control.
Now when it comes to all these suspected mechanisms, one thing to keep in mind is that they are just theories with little human evidence to back it up. However, despite the lack of research here and with long-term observational studies, it does seem like health organizations and governments are beginning to shy away from recommending sugar substitutes as a whole.
The American Heart Association and American Diabetes Association state that sugar substitutes can be used in moderation. But similar advocacy groups in Canada, the UK and Australia hold a different position. They don’t outright state you should avoid sugar substitutes, but instead of recommending their moderated use, they advise people to choose unsweetened items over anything sweetened. Now considering that low- and no-calorie sweeteners were once proudly promoted to Diabetics this is definitely an interesting change.
From a regulation standpoint, Health Canada has recently displayed some surprising bravery regarding sugar substitutes. In the 2019 update of their Dietary Guidelines they outright state “there are no well-established health benefits associated with the intake of sweeteners” and also “sugar substitutes do not need to be consumed to reduce the intake of free sugars.” Now, that is what I call a regulation clap-back. Coincidentally, the EU is currently undergoing a standard re-evaluation of all approved sweeteners, and so it will be interesting to see what scientific burn, if any, the Europeans come up with next year.
Artificial sweeteners, and sugar substitutes in general, were initially brought to market to provide options for consumers who wanted to satisfy their sweet tooth without the negative consequences of excess added sugar or calories. But while they’ve been on the market for decades, there still remains a lot of mystery regarding the long-term health impacts of these sweeteners. And yes, the overall results are mixed and inconclusive, but there also doesn’t seem to be much showing that they really benefit us in the long-run. And mechanistic theories aside, I have one outstanding question: isn’t swapping real sugar for substitutes just putting a band-aid on a bullet hole? At the end of the day, if too much added sugar is a public health issue, why not focus on re-calibrating our senses to not expect sweetness with every bite or sip? I mean, using sweeteners in place of sugar just gives me the same vibe as smoking vape pens instead of cigarettes. Sure one may be better on paper, but it still doesn’t solve the bigger problem at hand. Tackling our biological drive to eat sweet is no easy challenge, especially when we have become so used to sweetness in our diets. But trying to find a shortcut by tricking our sensory system with sugar substitutes, may actually lead us down a bad and bitter path.
That’s been the bite for today. Stay hungry.